Biology 20B Study Quiz
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Questions and Answers

What is the primary difference between whole body metabolic rate and mass-specific metabolic rate?

  • Whole body metabolic rate is independent of body size, while mass-specific varies significantly with size.
  • Whole body metabolic rate is averaged across various individuals, while mass-specific is measured solely in one individual.
  • Whole body metabolic rate considers total energy use regardless of size, while mass-specific accounts for energy use per unit mass. (correct)
  • Whole body metabolic rate is measured in calories per hour, while mass-specific is in calories per gram.

    • Which tissue type in animals is primarily responsible for coordination and communication?

  • Nervous tissue (correct)
  • Epithelial tissue
  • Connective tissue
  • Muscle tissue

    • In the context of body temperature regulation, which characteristic is typical of an ectotherm?

  • Has a high metabolic rate leading to high heat production.
  • Maintains a constant internal temperature regardless of the environment.
  • Relies primarily on environmental heat sources for body temperature. (correct)
  • Can adapt its metabolism significantly based on dietary changes.

    • How does the surface area to volume ratio change as body size increases?

    <p>Volume increases at a faster rate than surface area. (B)</p> Signup and view all the answers

    What happens to an endotherm in comparison to an ectotherm during cold environmental conditions?

    <p>The endotherm maintains stable body temperature due to metabolic heat production. (C)</p> Signup and view all the answers

    What does a plot of mass-specific metabolic rate versus body mass typically reveal?

    <p>A decreasing trend where smaller animals have higher mass-specific rates. (D)</p> Signup and view all the answers

    In the oxyhemoglobin saturation graph, what represents a condition of decreased oxygen affinity?

    <p>A rightward shift of the curve. (A)</p> Signup and view all the answers

    Which equation represents the water potential in a plant system?

    <p>Water potential = Solute potential + Pressure potential (A)</p> Signup and view all the answers

    What is the primary source of carbon for most plants?

    <p>Carbon Dioxide (B)</p> Signup and view all the answers

    What role do arbuscular mycorrhizae play in plant mutualism?

    <p>They enhance nutrient uptake for the plant in exchange for carbohydrates. (C)</p> Signup and view all the answers

    Which of the following statements correctly describes the pressure potential component of water potential?

    <p>It can be positive or zero and is influenced by turgor pressure. (D)</p> Signup and view all the answers

    What is the main reason that plants rely more on cell expansion than cell division compared to animals?

    <p>Cell wall rigidity allows plants to expand readily. (B)</p> Signup and view all the answers

    What is the primary source of heat for endotherms?

    <p>Metabolic processes (A)</p> Signup and view all the answers

    In the transpiration-cohesion-tension theory, what primarily causes water to be pulled upward in plants?

    <p>Evaporation of water from leaves creating a negative pressure. (D)</p> Signup and view all the answers

    Which term refers to the balance an organism maintains within its internal environment?

    <p>Homeostasis (B)</p> Signup and view all the answers

    In which process do polymers break down into monomers?

    <p>Digestion (C)</p> Signup and view all the answers

    What is the main distinction between absorption and digestion?

    <p>Digestion involves enzyme activity, while absorption involves nutrient transport. (C)</p> Signup and view all the answers

    What do the terms hypoosmotic and hyperosmotic refer to?

    <p>Osmotic pressure relative to another solution (B)</p> Signup and view all the answers

    Which of the following statements best describes the function of the Loop of Henle?

    <p>It plays a key role in urine concentration. (C)</p> Signup and view all the answers

    Which of the following is NOT a method animals use to manage osmoregulation?

    <p>Concentration of urine beyond body fluid osmolarity (D)</p> Signup and view all the answers

    How does the type of digestive fuel and site of digestion vary among major organs?

    <p>All fuels are absorbed in the small intestine. (A)</p> Signup and view all the answers

    What differentiates Type I diabetes from Type II diabetes?

    <p>Type I diabetes involves autoimmune destruction of insulin-producing cells. (B)</p> Signup and view all the answers

    What effect does alcohol have on urine output in relation to ADH levels?

    <p>Alcohol increases urine output by inhibiting ADH secretion. (D)</p> Signup and view all the answers

    What is the primary role of water in photosynthesis?

    <p>To supply electrons during the light reactions (D)</p> Signup and view all the answers

    What is the primary function of the pacemaker of the heart?

    <p>To conduct electrical impulses to the heart muscle. (B)</p> Signup and view all the answers

    Which component of blood is primarily responsible for oxygen transport?

    <p>Red blood cells (A)</p> Signup and view all the answers

    Which process is most directly linked to the enlargement of cells in phototropism?

    <p>Movement of auxin to the light-exposed side (B)</p> Signup and view all the answers

    How does rubisco function in the Calvin Cycle?

    <p>It fixes carbon dioxide into organic molecules (A)</p> Signup and view all the answers

    How does an action potential travel unidirectionally along a neuron?

    <p>By creating a positive feedback loop during depolarization. (C)</p> Signup and view all the answers

    What effect does sickle-cell anemia have on oxygen transport?

    <p>It leads to reduced oxygen transport due to abnormal red blood cell shape. (B)</p> Signup and view all the answers

    In plant reproduction, what distinguishes a monoecious species from a dioecious one?

    <p>Monoecious plants have both reproductive organs on the same individual, while dioecious have them on separate individuals. (D)</p> Signup and view all the answers

    What does the oxyhemoglobin disassociation curve illustrate?

    <p>The relationship between hemoglobin saturation and partial pressure of oxygen. (C)</p> Signup and view all the answers

    What term describes the process of double fertilization in plants?

    <p>One sperm cell fertilizes the egg and another fuses with polar nuclei to form endosperm. (D)</p> Signup and view all the answers

    What concept describes the trade-off in size seen in relation to surface area and volume in organisms?

    <p>Surface area to volume ratio (D)</p> Signup and view all the answers

    Which of the following denotes an ectotherm?

    <p>A reptile that relies on environmental heat sources. (C)</p> Signup and view all the answers

    What is the significance of the surface area to volume ratio in living organisms?

    <p>It influences the rate of heat loss or gain. (B)</p> Signup and view all the answers

    What function does chlorophyll serve in the photosystem?

    <p>It absorbs light energy for photosynthesis (A)</p> Signup and view all the answers

    In the context of metabolism, what distinguishes ectotherm conformers from endotherm regulators?

    <p>Ectotherms rely on external heat sources, while endotherms produce their own heat through metabolism. (C)</p> Signup and view all the answers

    During negative pressure breathing, which happens in mammals?

    <p>Diaphragm contraction increases lung volume. (C)</p> Signup and view all the answers

    What key role does myelin play in neurons?

    <p>It insulates axons to speed up signal transmission. (A)</p> Signup and view all the answers

    What occurs during the reaction center of a photosystem?

    <p>Electrons are ejected and sent to the electron transport chain. (B)</p> Signup and view all the answers

    What role does water potential play in plant function?

    <p>It aids in the expansion and turgidity of plant cells. (A)</p> Signup and view all the answers

    Which components contribute to the water potential equation in plants?

    <p>Solute potential and pressure potential (D)</p> Signup and view all the answers

    In the context of the oxyhemoglobin saturation graph, what does a right shift indicate?

    <p>Decreased affinity of hemoglobin for oxygen (D)</p> Signup and view all the answers

    What is a primary distinction between ectotherm conformers and endotherm regulators?

    <p>Endotherms maintain stable internal temperature through metabolic processes. (A)</p> Signup and view all the answers

    How does the surface area to volume ratio change with increasing organism size?

    <p>It decreases, which can limit gas exchange and waste elimination. (C)</p> Signup and view all the answers

    Why do plants prefer to use cell expansion rather than cell division for growth compared to animals?

    <p>Cell expansion allows plants to efficiently adapt to environmental changes. (B)</p> Signup and view all the answers

    How does the surface area to volume ratio change as an organism increases in size?

    <p>Volume increases faster than surface area. (B)</p> Signup and view all the answers

    Which of the following correctly represents the relationship of metabolic rates with body mass for endotherms?

    <p>A decreasing curve as body mass increases. (D)</p> Signup and view all the answers

    What does the oxyhemoglobin saturation graph illustrate about oxygen affinity under various conditions?

    <p>High levels of carbon dioxide decrease oxygen affinity. (C)</p> Signup and view all the answers

    In terms of temperature regulation, how do ectotherm conformers primarily function in relation to environmental temperature?

    <p>Their body temperature fluctuates with environmental temperature. (B)</p> Signup and view all the answers

    What distinguishes endotherms from ectotherms in terms of thermoregulation?

    <p>Endotherms generate their own heat through metabolism. (C)</p> Signup and view all the answers

    How might the shape of the SA:Vol curve change when comparing smaller to larger organisms?

    <p>It shows a hyperbolic decrease for larger organisms. (B)</p> Signup and view all the answers

    How do the metabolic rates of mass-specific and whole-body rates differ in animals?

    <p>Mass-specific rates decrease with increasing body mass. (A)</p> Signup and view all the answers

    Which of the following describes the relationship between the length of the Loop of Henle and a kidney's concentrating ability?

    <p>Longer loops enhance the kidney's ability to concentrate urine. (A)</p> Signup and view all the answers

    How do ectotherm conformers differ functionally from endotherm regulators?

    <p>Endotherm regulators actively maintain a stable internal temperature despite environmental changes. (A)</p> Signup and view all the answers

    What does the term 'surface area to volume ratio' imply for larger organisms?

    <p>Larger organisms have a lower surface area to volume ratio, affecting their heat retention. (C)</p> Signup and view all the answers

    Which factor primarily influences the water potential in plant cells?

    <p>Solute concentration and pressure potential (A)</p> Signup and view all the answers

    In the context of blood sugar regulation, which hormone primarily lowers blood glucose levels after a meal?

    <p>Insulin (A)</p> Signup and view all the answers

    In an oxyhemoglobin saturation graph, what does a rightward shift typically indicate?

    <p>Increased temperatures or decreased oxygen affinity (C)</p> Signup and view all the answers

    What is the main function of metabolic processes in endothermic organisms?

    <p>To generate internal heat for temperature regulation. (D)</p> Signup and view all the answers

    What primarily distinguishes ectotherm conformers from endotherm regulators?

    <p>Ectotherm conformers are dependent on environmental temperatures (A)</p> Signup and view all the answers

    Which statement best describes the function of osmoregulation in animals?

    <p>To balance the internal osmotic pressure relative to the external environment. (B)</p> Signup and view all the answers

    How does the surface area to volume ratio impact the metabolism of larger organisms?

    <p>Metabolism decreases with size due to a lower surface area to volume ratio (C)</p> Signup and view all the answers

    What is a key characteristic of the absorption process in the digestive system?

    <p>It occurs exclusively through cellular membranes. (B)</p> Signup and view all the answers

    Which of the following best describes the role of rubisco in plant metabolism?

    <p>It fixes carbon dioxide during the Calvin Cycle (A)</p> Signup and view all the answers

    Which mechanism represents a common way lipids are transported across epithelial cells?

    <p>Simple diffusion through cell membranes. (B)</p> Signup and view all the answers

    Which characteristic is typical of ectotherm conformers in relation to temperature?

    <p>They rely on external heat sources to regulate body temperature (A)</p> Signup and view all the answers

    What effect does a decrease in surface area to volume ratio have on physiological processes?

    <p>Decreased heat loss and gas exchange (D)</p> Signup and view all the answers

    What distinguishes Type I diabetes from Type II diabetes?

    <p>Type I is characterized by insulin deficiency due to autoimmune destruction of beta cells. (D)</p> Signup and view all the answers

    How does metabolism in larger animals differ from that in smaller animals?

    <p>Larger animals typically have slower metabolism rates (B)</p> Signup and view all the answers

    What would be the consequence of mutations affecting water potential mechanisms in plants?

    <p>Disruption of photosynthesis and growth (B)</p> Signup and view all the answers

    What is the relationship between water potential and auxin in plants?

    <p>Water potential alterations influence cell enlargement through auxin distribution (B)</p> Signup and view all the answers

    What does the water potential equation primarily account for?

    <p>Solute potential and pressure potential (C)</p> Signup and view all the answers

    What is indicated by a rightward shift in the oxyhemoglobin dissociation curve?

    <p>Decreased oxygen affinity due to lower pH (D)</p> Signup and view all the answers

    Which statement best explains the difference between ectotherm conformers and endotherm regulators?

    <p>Ectotherms rely on environmental temperatures, while endotherms maintain a stable internal temperature. (D)</p> Signup and view all the answers

    How does the surface area to volume ratio affect metabolic processes in organisms?

    <p>A higher ratio enhances the rate of heat exchange with the environment. (C)</p> Signup and view all the answers

    What is primarily illustrated by the oxyhemoglobin dissociation curve?

    <p>The relationship between hemoglobin saturation and oxygen availability (D)</p> Signup and view all the answers

    In the context of metabolic rates, how do ectotherm conformers typically differ from endotherm regulators?

    <p>Ectotherm conformers may exhibit fluctuating metabolic rates while endotherm regulators maintain consistent rates. (C)</p> Signup and view all the answers

    What would happen if the steep part of the oxyhemoglobin dissociation curve were shallower?

    <p>Oxygen saturation would be less sensitive to changes in partial pressure. (A)</p> Signup and view all the answers

    Which characteristic is essential for understanding how metabolic rates differ across species?

    <p>Body surface area in relation to volume (D)</p> Signup and view all the answers

    What impact does an increased solute concentration have on water potential in plant systems?

    <p>It lowers the water potential due to decreased solute potential. (B)</p> Signup and view all the answers

    What is a key consequence of high blood pressure on the circulatory system?

    <p>It can cause damage to blood vessel walls over time. (A)</p> Signup and view all the answers

    Which part of the plant primarily undergoes meiosis to generate spores?

    <p>Anther (B)</p> Signup and view all the answers

    What type of reproductive structure do monoecious plants exhibit?

    <p>Flowers containing both male and female parts on the same flower (B)</p> Signup and view all the answers

    In terms of plant reproduction, which statement accurately describes dioecious plants?

    <p>They have separate male and female flowers on different plants. (B)</p> Signup and view all the answers

    What is a crucial evolutionary advantage of sexual reproduction in flowering plants?

    <p>It promotes genetic diversity, enhancing adaptability. (C)</p> Signup and view all the answers

    What stage of the plant life cycle is characterized by having two sets of chromosomes?

    <p>Sporophyte stage (B)</p> Signup and view all the answers

    Which gene combinations lead to the specification of sepals and petals?

    <p>AA and AB (B)</p> Signup and view all the answers

    What characteristic prevents A and C genes from forming a dimer?

    <p>Lack of complementary binding sites (D)</p> Signup and view all the answers

    Which gene combination results in the formation of carpels?

    <p>CC (A)</p> Signup and view all the answers

    Which two gene classes can be combined to produce stamens?

    <p>B and C (A)</p> Signup and view all the answers

    What happens when two identical gene classes, such as B and B, are combined?

    <p>They form a non-functional dimer (B)</p> Signup and view all the answers

    In the context of organ formation, how does the expression of gene combinations differ across whorls?

    <p>Unique combinations result in the development of various organs (A)</p> Signup and view all the answers

    Why can't the gene combinations BB and AC generate an organ?

    <p>They do not fit together correctly (B)</p> Signup and view all the answers

    What is the primary characteristic of a perfect flower?

    <p>Contains both male and female parts (C)</p> Signup and view all the answers

    Which term describes a flower that has both male and female flowers on the same plant?

    <p>Monoecious (B)</p> Signup and view all the answers

    What primarily determines the flowering process in plants?

    <p>Internal size of phytomers (C), Environmental factors like temperature (D)</p> Signup and view all the answers

    What are the four main organs of a flower?

    <p>Sepals, Petals, Stamens, Carpels (A)</p> Signup and view all the answers

    In which structure do both male and female floral organs typically exist?

    <p>Perfect flowers (B)</p> Signup and view all the answers

    Which of the following correctly describes an imperfect flower?

    <p>Contains only one gender's reproductive organs (D)</p> Signup and view all the answers

    Which environmental factor does NOT typically trigger flowering in plants?

    <p>Soil pH (A)</p> Signup and view all the answers

    What is meant by the term 'whorls' in the context of flower structure?

    <p>Circular arrangements of floral organs around the stem (D)</p> Signup and view all the answers

    Which of the following statements best describes the role of organ identity genes in flower development?

    <p>They establish the identity and arrangement of floral organs. (A)</p> Signup and view all the answers

    Which of the following floral traits is most likely found in a dioecious plant?

    <p>Separate male and female plants (C)</p> Signup and view all the answers

    What process do C4 and CAM plants specifically utilize to aid in carbon fixation?

    <p>PEP for carbon fixation separated by space or time (C)</p> Signup and view all the answers

    In which part of the plant do C3 plants primarily fix CO2?

    <p>Mesophyll cells through the Calvin cycle (C)</p> Signup and view all the answers

    Which of the following best describes CAM plants?

    <p>They fix CO2 into four-carbon molecules at night. (D)</p> Signup and view all the answers

    What enzyme is primarily responsible for carbon fixation in C3 plants?

    <p>Rubisco (B)</p> Signup and view all the answers

    What differentiates the spatial and temporal separation of carbon fixation in C4 and CAM plants?

    <p>C4 plants fix CO2 in mesophyll and separate products in bundle-sheath cells. (B)</p> Signup and view all the answers

    What is the main function of chlorophyll in photosynthesis?

    <p>To convert light energy into chemical energy (B)</p> Signup and view all the answers

    Which statement accurately describes C4 plants?

    <p>They're designed to concentrate CO2 in bundle sheath cells. (D)</p> Signup and view all the answers

    What role does the reaction center play in photosynthesis?

    <p>It contains chlorophyll a and facilitates electron transport. (C)</p> Signup and view all the answers

    Which of the following accurately reflects photorespiration?

    <p>Rubisco binds to O2 instead of CO2 during this process. (D)</p> Signup and view all the answers

    How do CAM plants differ from C3 and C4 plants in their adaptation to hot climates?

    <p>They use PEP to concentrate CO2 at night. (D)</p> Signup and view all the answers

    What is a primary characteristic of C3 plants in contrast to C4 and CAM plants?

    <p>They are more susceptible to photorespiration. (B)</p> Signup and view all the answers

    Which component is exclusively involved in the photosynthetic light reactions?

    <p>ATP and NADPH production (C)</p> Signup and view all the answers

    What do C4 plants produce as a primary four-carbon compound during photosynthesis?

    <p>Oxaloacetate (D)</p> Signup and view all the answers

    Which enzyme is crucial for the fixation of carbon in C4 plants during the initial step?

    <p>PEP carboxylase (D)</p> Signup and view all the answers

    How do CAM plants utilize CO2 differently from C4 and C3 plants?

    <p>They absorb CO2 only at night. (D)</p> Signup and view all the answers

    In what cellular location is Rubisco found in C4 plants?

    <p>Bundle-sheath cells (C)</p> Signup and view all the answers

    What is a significant advantage of C4 and CAM plants over C3 plants in hot and dry environments?

    <p>They have specialized adaptations to reduce photorespiration. (A)</p> Signup and view all the answers

    Which of the following compounds is not produced by the Calvin Cycle?

    <p>Oxaloacetate (A)</p> Signup and view all the answers

    What distinguishes CAM plants from C4 plants in their carbon fixation strategy?

    <p>C4 plants separate the pathways spatially, while CAM plants separate them temporally. (B)</p> Signup and view all the answers

    What is the primary role of Rubisco in the Calvin Cycle?

    <p>It catalyzes the reaction between CO2 and RuBP. (D)</p> Signup and view all the answers

    What is the key distinction between C3 and C4 photosynthesis regarding CO2 fixation?

    <p>C4 plants fix CO2 before it enters the Calvin Cycle. (C)</p> Signup and view all the answers

    Which condition significantly influences whether some C3 plants can adopt a CAM pathway?

    <p>Temperature and precipitation (D)</p> Signup and view all the answers

    What is the primary function of the key enzyme Rubisco in the Calvin Cycle?

    <p>To fix carbon from CO2 into an organic molecule (D)</p> Signup and view all the answers

    Which of the following correctly describes the stages of the Calvin Cycle?

    <p>Carbon fixation, reduction, regeneration (B)</p> Signup and view all the answers

    During which stage of photosynthesis is glucose primarily produced?

    <p>Calvin Cycle (A)</p> Signup and view all the answers

    What is a unique feature of C4 plants compared to C3 plants in photosynthesis?

    <p>They have a specialized pathway that minimizes photorespiration. (D)</p> Signup and view all the answers

    Where in the chloroplast does the Calvin Cycle take place?

    <p>Stroma (D)</p> Signup and view all the answers

    What is the primary function of the light reactions in photosynthesis?

    <p>Convert light energy into chemical energy in the form of ATP and NADPH (D)</p> Signup and view all the answers

    Which statement correctly describes the Calvin Cycle?

    <p>It fixes carbon dioxide to produce organic sugars. (A)</p> Signup and view all the answers

    What tradeoff occurs when stomata open during photosynthesis?

    <p>Carbon dioxide enters the leaf but water is lost. (A)</p> Signup and view all the answers

    Which component is NOT produced during the light reactions of photosynthesis?

    <p>Glucose (A)</p> Signup and view all the answers

    In which part of the chloroplast do the light-independent reactions take place?

    <p>Stroma (A)</p> Signup and view all the answers

    What primary function is associated with auxin in plants?

    <p>Promotion of stem elongation (A)</p> Signup and view all the answers

    Which type of light is most effective for promoting phototropism in plants?

    <p>Red light (A)</p> Signup and view all the answers

    Which mechanism is primarily responsible for cell enlargement in response to auxin?

    <p>Increased water uptake and cell turgor pressure (A)</p> Signup and view all the answers

    How do plants primarily detect and respond to the quality of light?

    <p>Using photoreceptors that respond to specific light wavelengths (C)</p> Signup and view all the answers

    Which hormone plays a role in the differentiation of vascular tissue in plants?

    <p>Brassinosteroids (D)</p> Signup and view all the answers

    What is the primary function of auxin in plants?

    <p>Stimulates cell elongation on the shaded side of the plant (C)</p> Signup and view all the answers

    Which mechanism primarily describes how plants respond to light direction?

    <p>Phototropism (C)</p> Signup and view all the answers

    What does the term 'coleoptile' refer to in the context of plant growth?

    <p>The outer sheath of a young shoot (B)</p> Signup and view all the answers

    What is the significance of placing the agar block with auxin on only one side of the stem?

    <p>It demonstrates differential growth and bending towards light (A)</p> Signup and view all the answers

    How did Frits Went's experiment contribute to the understanding of plant hormones?

    <p>It established the chemical movement of hormones in response to light (A)</p> Signup and view all the answers

    What process occurs when H+ ions bind to clay, enhancing nutrient availability for plants?

    <p>Cation exchange (A)</p> Signup and view all the answers

    How do ectomycorrhizal fungi benefit woody plants?

    <p>By increasing root surface area (A)</p> Signup and view all the answers

    What role does rhizobia bacteria play in symbiosis with legumes?

    <p>They break down triple-bonded nitrogen (D)</p> Signup and view all the answers

    Which of the following best describes the role of macronutrients for plants?

    <p>They are essential for growth and development (D)</p> Signup and view all the answers

    What key mechanism allows plant roots to absorb more nutrients from the soil?

    <p>Pumping of H+ ions (C)</p> Signup and view all the answers

    Which nutrient type relies on clay particles for effective absorption through cation exchange?

    <p>Macronutrients (C)</p> Signup and view all the answers

    What role do negatively charged clay particles play in soil health?

    <p>They enhance water retention. (D)</p> Signup and view all the answers

    Which of the following is a primary difference between macronutrients and micronutrients for plants?

    <p>Macronutrients are needed in larger quantities. (C)</p> Signup and view all the answers

    In a mycorrhizal association, what benefit does the plant gain from the fungus?

    <p>Enhanced nutrient uptake. (A)</p> Signup and view all the answers

    How do rhizobia bacteria contribute to plant nutrition?

    <p>By converting atmospheric nitrogen to a usable form. (D)</p> Signup and view all the answers

    What occurs when guard cells become flaccid?

    <p>The stomata close to conserve water. (D)</p> Signup and view all the answers

    What triggers rapid changes in turgor pressure in guard cells?

    <p>Blue light affecting ion movement. (C)</p> Signup and view all the answers

    How does water potential primarily change within guard cells when they are turgid?

    <p>It becomes more negative as water enters the cells. (C)</p> Signup and view all the answers

    Which mechanism explains how sugars are transported in plants?

    <p>Pressure flow model relying on water potential changes. (C)</p> Signup and view all the answers

    What is the primary result of potassium ions rushing into guard cells?

    <p>Turgor pressure in guard cells increases. (B)</p> Signup and view all the answers

    What drives the movement of water into phloem during sugar transport?

    <p>More negative water potential in the phloem (C)</p> Signup and view all the answers

    What is the effect on water potential in phloem when sugar is deposited into a sink cell?

    <p>Water potential becomes less negative (C)</p> Signup and view all the answers

    In the context of girdling, which outcome can occur if a trunk is girdled?

    <p>Trees starve and potentially die (D)</p> Signup and view all the answers

    Why is turgor pressure essential for plant cells?

    <p>It supports the plant structure by maintaining cell shape (C)</p> Signup and view all the answers

    What happens to water movement in xylem during the process of sugar loading into phloem?

    <p>Water is drawn from xylem due to decreased potential in phloem (A)</p> Signup and view all the answers

    What is a primary function of epidermal tissue in plants?

    <p>Water retention and protection (A)</p> Signup and view all the answers

    Which of the following types of vascular tissue is responsible for transporting water and minerals?

    <p>Tracheids (B)</p> Signup and view all the answers

    What is a key characteristic of ground tissue in plants?

    <p>Provides structural support and storage (C)</p> Signup and view all the answers

    How does cell maturity affect the function of plant tissues?

    <p>Mature cells become more specialized for specific functions. (C)</p> Signup and view all the answers

    What is the main role of meristematic tissue in plants?

    <p>Cell division and growth (C)</p> Signup and view all the answers

    Which tissue type is primarily responsible for transporting nutrients in plants?

    <p>Phloem (D)</p> Signup and view all the answers

    What functional role do companion cells play in phloem tissue?

    <p>Assist sieve tubes in transporting nutrients (D)</p> Signup and view all the answers

    How do spongy mesophyll cells contribute to a leaf's function?

    <p>They allow for gas exchange through air spaces. (C)</p> Signup and view all the answers

    Which type of growth is primarily characterized by cell elongation in plants?

    <p>Primary growth (B)</p> Signup and view all the answers

    What is the function of the cuticle in plant leaves?

    <p>To prevent water loss and desiccation (A)</p> Signup and view all the answers

    At which locations in a plant does cell division primarily occur?

    <p>At tips of roots and shoots and lateral meristems (C)</p> Signup and view all the answers

    Which type of ground tissue is responsible for photosynthesis in leaves?

    <p>Parenchyma (A)</p> Signup and view all the answers

    Which cell type is responsible for structural support in younger stems and leaves?

    <p>Collenchyma (B)</p> Signup and view all the answers

    What distinguishes secondary growth from primary growth in plants?

    <p>Cell division occurs only in lateral meristems. (A)</p> Signup and view all the answers

    What initiates the rapid series of cell divisions after fertilization?

    <p>Changes in ion fluxes across the egg membrane (A)</p> Signup and view all the answers

    What is the pattern of cell division immediately following fertilization known as?

    <p>Cleavage (A)</p> Signup and view all the answers

    Which of the following describes the primary event of gastrulation in mammals?

    <p>Establishment of germ layers (C)</p> Signup and view all the answers

    At which stage of human development does implantation typically occur?

    <p>Day 6-7 (C)</p> Signup and view all the answers

    During organogenesis, which of the following is primarily developed from the ectoderm?

    <p>Nervous system (B)</p> Signup and view all the answers

    What is the primary role of the trophoblast during implantation?

    <p>To facilitate the blastocyst’s integration into the uterine wall (D)</p> Signup and view all the answers

    Which structure of the inner cell mass will ultimately become the embryo?

    <p>Epiblast (A)</p> Signup and view all the answers

    How does the blastocoel contribute to the process of gastrulation?

    <p>It allows for cell movement to form germ layers (A)</p> Signup and view all the answers

    Which germ layer is responsible for the development of the circulatory system and skeleton?

    <p>Mesoderm (C)</p> Signup and view all the answers

    What is the main purpose of chorionic villi during implantation?

    <p>To increase surface area for maternal blood contact (B)</p> Signup and view all the answers

    Prior to the embryonic tissue split, what significant role does the trophoblast play?

    <p>It secretes adhesion molecules and proteases (A)</p> Signup and view all the answers

    What is a key characteristic of cell division during the early stages of development?

    <p>It is asynchronous and can be slow (B)</p> Signup and view all the answers

    Which cell layer is the outermost in a developing embryo?

    <p>Ectoderm (C)</p> Signup and view all the answers

    What event follows the formation of the blastocyst in early embryonic development?

    <p>Gastrulation (A)</p> Signup and view all the answers

    Which statement accurately describes the inner cell mass at the 32 cell stage?

    <p>It contains cells that will become the embryo (C)</p> Signup and view all the answers

    What is the main purpose of transcription factors in development?

    <p>Determining the fate of a cell (A)</p> Signup and view all the answers

    Which concept describes the specific pattern of gene expression that leads to the development of distinct cell types?

    <p>Differential Gene Expression (D)</p> Signup and view all the answers

    In the context of development, what does the term 'cell potency' refer to?

    <p>The general potential of cells to differentiate into various cell types (A)</p> Signup and view all the answers

    How do morphogens influence the development of an organism?

    <p>By establishing concentration gradients that dictate cell fate (B)</p> Signup and view all the answers

    What is the role of the gene cascade during development?

    <p>To initiate a sequential activation of genes (C)</p> Signup and view all the answers

    What type of cells can give rise to any cell type during development?

    <p>Totipotent cells (B)</p> Signup and view all the answers

    Which process involves setting the fate of a cell before it undergoes differentiation?

    <p>Determination (B)</p> Signup and view all the answers

    In developmental biology, which term describes a cell's ability to become multiple cell types?

    <p>Potency (D)</p> Signup and view all the answers

    What is the function of morphogens in development?

    <p>To regulate gene cascades (C)</p> Signup and view all the answers

    Which stem cells are capable of differentiating into several related cell types?

    <p>Multipotent stem cells (D)</p> Signup and view all the answers

    What is the primary mechanism behind differential gene expression in cells?

    <p>Cytoplasmic segregation (D)</p> Signup and view all the answers

    During differentiation, what term describes the actual process of a cell becoming a specific type of cell?

    <p>Differentiation (B)</p> Signup and view all the answers

    What defines the difference between pluripotent and multipotent stem cells?

    <p>Pluripotent can form any cell type, while multipotent can form several related types. (C)</p> Signup and view all the answers

    Which factors are primarily responsible for activating specific genes in developmental pathways?

    <p>Transcription factors (D)</p> Signup and view all the answers

    What does the process of cell induction refer to in the context of development?

    <p>The stimulation of cells to differentiate under the influence of neighboring cells (B)</p> Signup and view all the answers

    What is the primary role of sodium (Na+) voltage-gated channels in the generation of action potentials?

    <p>To initiate depolarization by allowing Na+ to flow into the neuron (A)</p> Signup and view all the answers

    How does the resting membrane potential of a neuron maintain itself at approximately -60 mV?

    <p>Through the action of K+ leak channels that allow K+ ions to exit the neuron (C)</p> Signup and view all the answers

    What occurs at the synaptic terminal of a neuron when an action potential reaches this area?

    <p>Neurotransmitters are released, causing a response in the next neuron (B)</p> Signup and view all the answers

    What is the significance of positive feedback during an action potential?

    <p>It amplifies the initial depolarization by opening more Na+ channels (C)</p> Signup and view all the answers

    Which of the following correctly describes the flow of signals through a neuron upon sensory stimulation?

    <p>Signal moves from dendrites to the axon terminal along the axon (B)</p> Signup and view all the answers

    What role does myelin sheath have in neuronal function?

    <p>It separates opposite charges to reduce attraction. (C)</p> Signup and view all the answers

    How does the size of a neuron affect the speed of action potentials?

    <p>Larger neurons conduct action potentials faster. (B)</p> Signup and view all the answers

    What is the effect of an inhibitory drug on the resting membrane potential of a postsynaptic neuron?

    <p>It creates hyperpolarization, making action potential generation more difficult. (C)</p> Signup and view all the answers

    What process describes how neurotransmitters are released into the synaptic cleft?

    <p>Exocytosis (B)</p> Signup and view all the answers

    What consequence does a myelin sheath have on the transmission of action potentials?

    <p>It enables saltatory conduction by allowing APs to jump from node to node. (D)</p> Signup and view all the answers

    Which of the following best represents the resting membrane potential established in a neuron?

    <p>Higher concentration of potassium ions inside than outside. (A)</p> Signup and view all the answers

    How does an action potential travel down an unmyelinated neuron?

    <p>The action potential travels continuously without interruption. (C)</p> Signup and view all the answers

    What impact does the node of Ranvier have on action potentials?

    <p>It allows for unidirectional conduction of the action potential. (D)</p> Signup and view all the answers

    What initiates the depolarization phase of an action potential?

    <p>An influx of sodium ions into the neuron. (A)</p> Signup and view all the answers

    What effect does action potential propagation have on synaptic transmission?

    <p>It induces the release of neurotransmitters into the synaptic cleft. (C)</p> Signup and view all the answers

    What occurs during negative pressure breathing in mammals?

    <p>Air is drawn into the lungs. (C)</p> Signup and view all the answers

    What is the vital capacity in respiratory terms?

    <p>The maximum tidal volume during forced breathing. (B)</p> Signup and view all the answers

    Which statement accurately describes residual volume?

    <p>Air volume that remains in the lungs after full exhalation. (B)</p> Signup and view all the answers

    How do volume and pressure change when inhaling?

    <p>Volume increases and pressure decreases. (C)</p> Signup and view all the answers

    What is tidal volume in the context of respiration?

    <p>The amount of air inhaled or exhaled during normal breathing. (A)</p> Signup and view all the answers

    What is the primary advantage of a left-shifted hemoglobin curve for a fetus?

    <p>Higher affinity for oxygen to prioritize oxygen delivery (A)</p> Signup and view all the answers

    How does cooperation in oxygen-hemoglobin saturation impact oxygen delivery?

    <p>It increases oxygen release from hemoglobin when needed. (B)</p> Signup and view all the answers

    What characteristic of llama hemoglobin allows it to thrive in high-altitude environments?

    <p>It has a different amino acid sequence resulting in higher affinity. (C)</p> Signup and view all the answers

    In the context of oxygen-hemoglobin dissociation curves, what does a left shift in the curve indicate for Covid patients?

    <p>Preservation of oxygen for vital organs. (D)</p> Signup and view all the answers

    What role does surfactant play in the alveoli during gas exchange?

    <p>It helps maintain alveolar stability by reducing surface tension. (C)</p> Signup and view all the answers

    Which of the following animals would most likely have a left-shifted oxygen-hemoglobin dissociation curve?

    <p>An animal adapted to high altitude. (C)</p> Signup and view all the answers

    What is the primary mechanism driving the movement of oxygen from alveoli to blood in the lungs?

    <p>Diffusion due to concentration gradients. (D)</p> Signup and view all the answers

    Which feature is NOT characteristic of the closed circulatory system?

    <p>Blood is mixed with oxygen in the open spaces of the body. (D)</p> Signup and view all the answers

    What occurs in the lungs during negative pressure breathing?

    <p>The intrapleural pressure becomes more negative, drawing air in. (B)</p> Signup and view all the answers

    Which part of the ECG indicates a first-degree AV block?

    <p>PR interval (C)</p> Signup and view all the answers

    In a Type I heart block, how does the electrical signal behave before a skipped beat occurs?

    <p>It gets slower and slower. (A)</p> Signup and view all the answers

    Which phase of the cardiac cycle primarily corresponds to depolarization of the ventricles?

    <p>ventricular systole (C)</p> Signup and view all the answers

    What role does the SA node primarily play in the cardiac conduction system?

    <p>It initiates and regulates the heartbeat. (D)</p> Signup and view all the answers

    Which type of heart block is characterized by the pattern of failure to conduct an impulse, but also has occasional successful transmissions?

    <p>Mobitz Type I (Wenckebach) (C)</p> Signup and view all the answers

    What is the main role of gap junctions in cardiac muscle?

    <p>To transmit electrical signals quickly (D)</p> Signup and view all the answers

    During which phase of the cardiac cycle do the ventricles contract?

    <p>Systole (A)</p> Signup and view all the answers

    What electrical change corresponds to depolarization in cardiac muscle cells?

    <p>An influx of sodium ions (B)</p> Signup and view all the answers

    What is the primary function of the SA node in the heart?

    <p>To initiate the heartbeat (A)</p> Signup and view all the answers

    What characterizes a third-degree heart block?

    <p>Complete dissociation between atrial and ventricular activity (B)</p> Signup and view all the answers

    What occurs during diastole in the heart?

    <p>Ventricles fill with blood (D)</p> Signup and view all the answers

    Which physiological change signals repolarization in cardiac muscle cells?

    <p>Potassium ions exiting the cell (B)</p> Signup and view all the answers

    In what order do the electrical signals travel through the heart during contraction?

    <p>SA node → AV node → Bundle of His → Purkinje fibers (C)</p> Signup and view all the answers

    What effect does an increased total area have on blood pressure?

    <p>Decreases blood pressure (D)</p> Signup and view all the answers

    What is the primary function of the glomerulus in the kidney?

    <p>To filter blood plasma creating filtrate (D)</p> Signup and view all the answers

    Juxtamedullary nephrons are unique because they allow for the:

    <p>Concentration of urine above body fluid osmolarity (B)</p> Signup and view all the answers

    What role does secretion play in kidney function?

    <p>It selectively adds substances to the filtrate (C)</p> Signup and view all the answers

    Osmoregulation is critical for maintaining which aspect of homeostasis?

    <p>Fluid and electrolyte balance (B)</p> Signup and view all the answers

    What is true regarding the structure of the nephron?

    <p>Cortical nephrons have shorter loops of Henle than juxtamedullary nephrons (C)</p> Signup and view all the answers

    What primarily establishes the concentration gradient in the medulla?

    <p>Salts are actively pumped out of the ascending limb (C)</p> Signup and view all the answers

    Why does the descending limb of the loop of Henle become concentrated with salt?

    <p>It is permeable to water but not to salt (B)</p> Signup and view all the answers

    What role do the vasa recta play in the kidney's function?

    <p>They maintain the concentration gradient by carrying away water and salts (A)</p> Signup and view all the answers

    In which part of the kidney is urine primarily concentrated?

    <p>Collecting duct (C)</p> Signup and view all the answers

    How does the loop of Henle function as a counter-current multiplier?

    <p>Each side of the limb aids in the osmotic difference (B)</p> Signup and view all the answers

    What is the consequence of water leaving the descending limb on the concentration gradient?

    <p>It enhances the gradient by increasing salt concentration (A)</p> Signup and view all the answers

    Which nephron structure is crucial for creating the osmotic gradient in the medulla?

    <p>Loop of Henle (D)</p> Signup and view all the answers

    What happens to the filtrate as it passes through the collecting duct?

    <p>It becomes more concentrated as water is reabsorbed (B)</p> Signup and view all the answers

    What is the primary function of active transport in the ascending limb of the loop of Henle?

    <p>To pump salts out into the interstitial fluid (B)</p> Signup and view all the answers

    Why is urine not concentrated in the loop of Henle itself?

    <p>Concentration only occurs in the collecting duct (B)</p> Signup and view all the answers

    What is measured by the field metabolic rate (FMR)?

    <p>Average MR over a seasonal period (C)</p> Signup and view all the answers

    How does the resting metabolic rate (RMR) respond to increasing environmental temperatures?

    <p>RMR shows a significant linear increase (C)</p> Signup and view all the answers

    Which characteristic distinguishes endothermic regulators from ectothermic conformers?

    <p>Endothermic regulators maintain a stable internal temperature despite external changes (C)</p> Signup and view all the answers

    What type of scale is used to represent the values on the axes in metabolic rate graphs?

    <p>Logarithmic scale (A)</p> Signup and view all the answers

    What can be inferred about the metabolic rates of reptiles compared to birds and mammals?

    <p>Reptiles are generally more energy efficient due to their ectothermic nature (C)</p> Signup and view all the answers

    What is the formula used to calculate George's mass-specific metabolic rate?

    <p>Total calories burned per day divided by body weight (B)</p> Signup and view all the answers

    How does mass-specific metabolic rate differ from whole body metabolic rate?

    <p>Mass-specific metabolic rate considers body mass, while whole body metabolic rate does not (B)</p> Signup and view all the answers

    What describes the relationship between the thermal neutral zone and energy expenditure?

    <p>It represents a range where no extra energy is needed for temperature regulation (D)</p> Signup and view all the answers

    What energetic advantage do endotherms have in cold environments compared to ectotherms?

    <p>Endotherms can maintain a stable body temperature using metabolic rates (C)</p> Signup and view all the answers

    If George the Elephant weighs 4000 kg and has a mass-specific metabolic rate of 11.98 kcal/day * kg, what is his total daily energy expenditure?

    <p>47,907 Kcals/day (C)</p> Signup and view all the answers

    What could a person infer if a graph shows a steep increase in metabolic rate as environmental temperature decreases?

    <p>The animal is endothermic and can regulate its body temperature through metabolic processes (B)</p> Signup and view all the answers

    In the context of thermal regulation, what role does the lower critical temperature play?

    <p>It represents the temperature below which additional energy is required to maintain body temperature (C)</p> Signup and view all the answers

    What is a potential challenge for ectotherms in maintaining metabolic functions?

    <p>They rely heavily on external temperature to manage body functions (A)</p> Signup and view all the answers

    What does an increased mass-specific metabolic rate often indicate about an organism's behavior or activity levels?

    <p>The organism is actively foraging or undergoing substantial physical activity (C)</p> Signup and view all the answers

    What is the primary function of epithelial tissue?

    <p>To secrete and absorb nutrients (D)</p> Signup and view all the answers

    How does the structure of muscle tissue relate to its function?

    <p>Muscular fibers composed of myofibrils enable motion (C)</p> Signup and view all the answers

    Which connective tissue type primarily serves as energy storage in the body?

    <p>Adipose tissue (A)</p> Signup and view all the answers

    What characteristic is unique to nervous tissue compared to other tissue types?

    <p>It processes and transmits information through specialized cells (A)</p> Signup and view all the answers

    Which type of epithelial tissue functions in protection and can be found in multiple layers?

    <p>Stratified squamous epithelium (D)</p> Signup and view all the answers

    What is the primary function of connective tissues in animals?

    <p>Providing structural support and connection (B)</p> Signup and view all the answers

    How does the structure of epithelial tissue relate to its function?

    <p>Its cells are tightly packed to form protective barriers. (C)</p> Signup and view all the answers

    Which of the following types of tissue primarily aids in maintaining homeostasis within the body?

    <p>Nervous tissue (A)</p> Signup and view all the answers

    What is the significance of surface area to volume ratio in animal tissues?

    <p>It affects nutrient absorption and metabolic efficiency. (A)</p> Signup and view all the answers

    Which type of connective tissue is responsible for storing energy and insulating the body?

    <p>Adipose tissue (A)</p> Signup and view all the answers

    What are the four main types of animal tissues?

    <p>Muscle, Epithelial, Nervous, Connective (B)</p> Signup and view all the answers

    How do muscle tissues contribute to an animal's homeostasis?

    <p>By generating heat through contraction (C)</p> Signup and view all the answers

    Which tissue type is primarily involved in the rapid transmission of signals throughout the body?

    <p>Nervous tissue (B)</p> Signup and view all the answers

    What aspect of connective tissue is crucial for its function in energy metabolism?

    <p>The presence of blood vessels for nutrient transport (D)</p> Signup and view all the answers

    How do specialized tissues impact the overall function of an animal?

    <p>They enable the organism to adapt to various environments. (C)</p> Signup and view all the answers

    How does understanding the relationship between structure and function aid in evolutionary biology?

    <p>It showcases adaptations in various species over time. (B)</p> Signup and view all the answers

    Which type of tissue in animals is primarily responsible for movement?

    <p>Muscle tissue (B)</p> Signup and view all the answers

    What happens to the surface area to volume ratio as an animal increases in size?

    <p>The ratio decreases. (D)</p> Signup and view all the answers

    How do smaller animals primarily manage heat compared to larger animals?

    <p>They dissipate heat faster due to a larger surface area to volume ratio. (D)</p> Signup and view all the answers

    What is a significant consequence of the surface area to volume ratio in physiological processes?

    <p>It affects nutrient absorption rates in small animals. (A)</p> Signup and view all the answers

    What does the concept of surface to volume ratio primarily influence in organisms?

    <p>The ability to exchange materials with the environment (B)</p> Signup and view all the answers

    What is the primary function of stratified squamous tissue in animals?

    <p>Protection against abrasion (D)</p> Signup and view all the answers

    Which type of tissue is primarily responsible for absorption and secretion in animal organs?

    <p>Simple columnar epithelium (D)</p> Signup and view all the answers

    Which statement best reflects the relationship between structure and function in biology?

    <p>Structure and function are interdependent (C)</p> Signup and view all the answers

    What limits the exchange processes of single-celled organisms compared to multicellular organisms?

    <p>They lack specialized tissues (C)</p> Signup and view all the answers

    Why is the size of an organism a critical factor concerning surface to volume ratios?

    <p>Larger organisms have less effective material exchange (A)</p> Signup and view all the answers

    Which of the following types of tissues primarily conducts impulses and coordinates body activities?

    <p>Nervous tissue (B)</p> Signup and view all the answers

    What is a primary challenge faced by larger animals in relation to their surface to volume ratio?

    <p>Decreased ability to exchange gases (A)</p> Signup and view all the answers

    Which of the following statements accurately describes a key characteristic of specialized tissues in multicellular organisms?

    <p>Specialized tissues enhance the efficiency of biological processes (D)</p> Signup and view all the answers

    Flashcards

    Endothermy

    Regulation of body temperature using metabolic heat.

    Ectothermy

    Regulation of body temperature using external heat sources.

    Homeostasis

    Maintaining a stable internal environment.

    Negative Feedback Loop

    A loop that reduces a deviation from a set point.

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    Positive Feedback Loop

    A loop that amplifies a deviation from a set point.

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    Digestion

    Breakdown of polymers into monomers.

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    Absorption

    Movement of molecules across cell membranes.

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    Extracellular digestion

    Digestion outside of the cell.

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    Hypoosmotic

    Having a lower solute concentration (and thus higher water concentration) than another solution.

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    Hyperosmotic

    Having a higher solute concentration (and thus lower water concentration) than another solution.

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    Plant Meristems

    Regions of actively dividing plant cells responsible for growth.

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    Secondary Growth

    Plant growth that increases the width or girth of stems and roots (wood growth).

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    Water Transport in Plants

    Water moves up a plant by the transpiration-cohesion-tension theory; water is pulled up, not pushed.

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    Nitrogen Fixation

    The process of converting atmospheric nitrogen into a usable form for plants, is done by bacteria, not plants.

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    Auxin Polar Transport

    Auxin, a plant hormone, moves in one direction in a plant due to specific transport proteins.

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    Cardiac Output

    The amount of blood pumped by the heart per minute.

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    Blood Pressure Equation

    Blood pressure = Cardiac output x Total Peripheral Resistance (TPR).

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    Negative Pressure Breathing

    Breathing driven by the expansion and contraction of the lungs, creating a pressure difference.

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    Action Potential

    Rapid change in electrical membrane potential of a neuron or muscle cell.

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    Oxyhemoglobin Dissociation Curve

    Shows the relationship between oxygen saturation of hemoglobin and the partial pressure of oxygen.

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    Blood Brain Barrier

    Specialized structure that regulates the passage of materials from blood to brain tissue.

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    Hemoglobin

    Protein in red blood cells that carries oxygen.

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    Fetal Hemoglobin

    Form of hemoglobin in a fetus that has a higher affinity for oxygen.

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    Single Circuit Circulation

    Circulatory system with a single loop of blood vessels.

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    Closed Circulatory System

    A circulatory system in which blood is contained within vessels and does not directly bathe organs.

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    Phototropism mechanism

    Phototropism is the growth of a plant towards or away from a light source, primarily due to differential cell elongation, not division.

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    Photosynthesis reactants

    Photosynthesis uses carbon dioxide, water, and light energy to produce glucose and oxygen.

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    Calvin Cycle reactants

    The Calvin Cycle uses carbon dioxide and other molecules to produce glucose.

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    Light-dependent reactions electrons source

    Electrons for light-dependent reactions come from water molecules.

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    Photosystem role

    Photosystems are protein complexes that absorb light energy and transfer it to electrons, initiating electron transport chains.

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    Chlorophyll role

    Chlorophyll absorbs light energy from the visible spectrum, primarily red and blue light, and is critical for photosynthesis.

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    Rubisco role

    Rubisco is an enzyme that fixes carbon dioxide during the Calvin cycle of photosynthesis.

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    Alternation of generations

    Alternation of generations refers to the life cycle of plants, featuring both a multicellular haploid (gametophyte) and a multicellular diploid (sporophyte) phase.

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    Monoecious vs. Dioecious

    Monoecious plants have both male and female reproductive structures on the same plant, whereas dioecious plants have separate male and female plants.

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    Double fertilization

    Double fertilization is a process unique to plants where one sperm fertilizes the egg and another fuses with polar nuclei to form endosperm.

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    Surface Area:Volume Ratio

    The ratio of a cell or organism's surface area to its volume. It influences how quickly substances can enter and leave the cell or organism.

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    Whole Body Metabolic Rate

    The total energy expenditure of an organism per unit time. It reflects the organism's overall energy needs.

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    Mass-Specific Metabolic Rate

    The energy expenditure per unit mass of an organism per unit time. It helps compare metabolic rates of organisms of different sizes.

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    Regulating vs. Conforming

    Two strategies for maintaining internal body conditions. Regulators actively maintain a stable internal environment, while conformers allow their internal conditions to fluctuate with the external environment.

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    What is the relationship between body size and surface area to volume ratio?

    As body size increases, the surface area to volume ratio decreases. Smaller objects have a higher ratio, allowing for faster exchange of materials.

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    How do whole body and mass-specific metabolic rates change with body size?

    Whole body metabolic rate increases with body size, while mass-specific metabolic rate decreases with body size. This means larger animals need more energy overall, but on a per-unit-mass basis, smaller animals use more energy.

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    Surface Area to Volume Ratio

    The ratio of an object's surface area to its volume. It influences how quickly substances can enter and leave the object.

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    Regulators vs. Conformers

    Two strategies for maintaining internal body conditions. Regulators actively maintain a stable internal environment, while conformers allow their internal conditions to fluctuate with the external environment.

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    Body Size and Surface Area to Volume Ratio

    As body size increases, the surface area to volume ratio decreases. Smaller objects have a higher ratio, allowing for faster exchange of materials.

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    Body Size and Metabolic Rates

    Whole body metabolic rate increases with body size, while mass-specific metabolic rate decreases with body size. Larger animals need more energy overall, but on a per-unit-mass basis, smaller animals use more energy.

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    Endotherm Heat Source

    Endothermic organisms generate heat primarily through their own metabolism.

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    Ectotherm Heat Source

    Ectothermic organisms rely mainly on external sources of heat like the sun or environment.

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    Homeostasis Definition

    Homeostasis is the maintenance of a stable internal environment in an organism, despite external changes.

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    Digestion vs. Absorption

    Digestion breaks down large food molecules into smaller ones, while absorption moves these smaller molecules across cell membranes.

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    Lipid Transport Across Epithelial Cells

    Lipids are transported across epithelial cells in the digestive system using a combination of diffusion and protein-mediated transport.

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    Hormonal Regulation of Digestion

    Hormones like gastrin, secretin, and cholecystokinin regulate different stages of digestion.

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    Blood Sugar, Insulin, and Glucagon

    Insulin lowers blood sugar levels, while glucagon raises them. Both are regulated by the pancreas in response to meal intake.

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    Phototropism: Cell Division or Elongation?

    Phototropism, a plant's growth towards light, is primarily driven by cell elongation, not cell division.

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    Photosynthesis Equation

    Photosynthesis combines carbon dioxide (CO2) and water (H2O) using light energy to produce glucose (C6H12O6) and oxygen (O2).

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    Photosystem: Antennae?

    A photosystem is like an antenna that captures light energy and directs it to the reaction center.

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    What is Rubisco's Role?

    Rubisco is an enzyme that fixes carbon dioxide (CO2) during the Calvin cycle, essentially incorporating it into sugar.

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    Monoecious vs. Dioecious Plants

    Monoecious plants have both male and female reproductive parts on the same plant, while dioecious plants have separate male and female plants.

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    What is Endosperm?

    Endosperm is a nutrient-rich tissue in seeds that nourishes the developing embryo.

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    What is a Fruit?

    A fruit develops from the ovary of a flower and typically encloses seeds, often serving to protect and/or disperse them.

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    Open Circulatory System

    A circulatory system where blood is not always contained within vessels and directly bathes organs.

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    Double Circuit Circulation

    A circulatory system with two separate loops of blood vessels, passing through the heart twice per circuit.

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    Total Peripheral Resistance (TPR)

    The resistance to blood flow in the circulatory system.

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    Hemoglobin's Role

    A protein in red blood cells that carries oxygen to the tissues.

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    Meristem Function

    Meristems are regions of actively dividing plant cells responsible for plant growth. They are important for increasing plant length, width, and the formation of new tissues.

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    Water Potential Equation

    Water potential (Ψ) is the potential energy of water in a system. It is calculated as Ψ = Ψp + Ψs, where Ψp is pressure potential, and Ψs is solute potential. Water always moves from areas of higher water potential to areas of lower water potential.

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    Guard Cell Opening

    Guard cells surround stomata, pores on plant leaves that regulate gas exchange. When guard cells take up water, they become turgid and open the stomata. This happens because water uptake increases turgor pressure, making the cells swell and open the pore.

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    Transpiration-Cohesion-Tension Theory

    This theory explains how water is transported upwards in a plant. Transpiration creates tension in the xylem, pulling water upwards. Cohesion between water molecules and adhesion to xylem walls maintain a continuous water column.

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    Haploid Spore

    A reproductive cell that contains only one set of chromosomes (half the number of chromosomes present in the sporophyte).

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    Perfect Flower

    A flower containing both male and female reproductive organs (stamen and carpel).

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    Monoecious Plant

    A plant having separate male and female flowers on the same individual plant.

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    Dioecious Plant

    A plant having separate male and female flowers on different individual plants.

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    Organ Identity Genes

    Genes that control the development of different plant organs, like sepals, petals, stamens, and carpels.

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    A, B, and C Gene Classes

    Three classes of genes (A, B, and C) that control flower development. Each codes for a part of a transcription factor dimer, which binds to DNA to control gene expression.

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    Transcription Factor Dimers

    Pairs of proteins that bind to DNA and control gene expression. Each member of the pair is coded by a different organ identity gene (A, B, or C).

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    Whorls: Different Organs

    The different parts of a flower, like sepals, petals, stamens, and carpels, are arranged in concentric circles called whorls. Each whorl develops due to the specific combination of A, B, and C genes expressed there.

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    Why can't A and C genes combine?

    A and C genes cannot directly combine because their protein products cannot physically interact and form a functional dimer. This prevents the development of abnormal organs in the flower.

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    What happens when B genes combine?

    When B genes combine, they form a functional B-B dimer, leading to the development of petals.

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    A, B, and C Gene Combinations

    Different combinations of A, B, and C genes determine the development of specific flower organs. For example, A + A genes code for sepals, A + B genes for petals, B + C genes for stamens, and C + C genes for carpels.

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    Floral Meristem

    The growing tip of a plant that develops into a flower.

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    Sepals

    The outermost whorl (circle) of flower parts, usually green and leaf-like.

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    Petals

    The colorful whorl of flower parts, often attracting pollinators.

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    Stamens

    The male reproductive parts of a flower, consisting of an anther and a filament.

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    Carpels

    The female reproductive parts of a flower, consisting of a stigma, style, and ovary.

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    Photorespiration

    A process where Rubisco binds to oxygen instead of carbon dioxide, reducing photosynthetic efficiency. It occurs when carbon dioxide levels are low and oxygen levels are high.

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    C3 Plants

    Plants that use the Calvin cycle as their primary carbon fixation pathway. They are susceptible to photorespiration.

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    C4 Plants

    Plants that use a specialized pathway to concentrate carbon dioxide, reducing photorespiration. They have PEP carboxylase, which binds to CO2.

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    CAM Plants

    Plants that open their stomata at night to fix carbon dioxide and store it as an acid. They have PEP carboxylase and open stomata at night.

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    Bundle Sheath Cells

    Specialized cells in C4 plants where the Calvin cycle takes place. These cells have Rubisco and concentrate carbon dioxide.

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    PEP Carboxylase

    An enzyme in C4 and CAM plants that has a higher affinity for carbon dioxide than Rubisco. It helps concentrate CO2 for the Calvin Cycle.

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    Mesophyll Cells

    The main photosynthetic cells in leaves, where carbon dioxide is initially fixed in C3 and C4 plants.

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    C3 Photosynthesis

    The most common type of photosynthesis where carbon dioxide is fixed directly into a three-carbon compound (3-PGA) by the enzyme Rubisco.

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    C4 Photosynthesis

    A type of photosynthesis where carbon dioxide is first fixed into a four-carbon compound (oxaloacetate) by the enzyme PEP carboxylase before being incorporated into the Calvin cycle.

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    CAM Photosynthesis

    A type of photosynthesis where carbon dioxide is fixed into a four-carbon compound at night and then incorporated into the Calvin cycle during the day.

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    Rubisco

    An enzyme found in all plants that catalyzes the first step of the Calvin cycle, fixing carbon dioxide into RuBP.

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    Where is PEP carboxylase found?

    In C4 plants, PEP carboxylase is located in the mesophyll cells, while Rubisco is in the bundle sheath cells. In CAM plants, both PEP carboxylase and Rubisco are found in mesophyll cells, but they're active at different times.

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    What is the benefit of separating PEP and Rubisco?

    Separating PEP and Rubisco minimizes photorespiration and allows C4 and CAM plants to thrive in harsh environments.

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    Why are C4 and CAM plants better adapted to hot, dry environments?

    C4 and CAM plants use PEP carboxylase to fix carbon when the stomata are closed, reducing water loss. They also minimize photorespiration, which is more common in hot, dry conditions.

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    Can a plant be both C3 and C4 or C3 and CAM?

    A plant can only be one type of photosynthesis (C3, C4, or CAM). However, some C3 plants can temporarily switch to a CAM pathway in response to environmental conditions.

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    Photosynthesis overview

    The process by which plants use sunlight, carbon dioxide, and water to produce glucose (sugar) and oxygen.

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    Calvin Cycle

    The series of biochemical reactions that convert carbon dioxide into glucose using energy from sunlight.

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    What is the purpose of the Calvin Cycle?

    The Calvin Cycle aims to fix carbon, which means to convert carbon dioxide into glucose (sugars) to provide energy for the plant.

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    Light-Dependent Reactions

    The reactions in photosynthesis that directly use light energy to produce ATP and NADPH, which power the Calvin Cycle.

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    Light Reactions

    The light reactions occur in the thylakoid membranes of chloroplasts. They capture light energy and use it to produce ATP and NADPH. These products are then used in the Calvin Cycle for sugar production.

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    Stomata Trade-off

    When stomata open to allow carbon dioxide in for photosynthesis, water is also lost through transpiration. This trade-off is necessary for plants but can lead to water stress.

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    Coleoptile

    The protective sheath covering the young shoot of a grass seedling. It plays a vital role in phototropism, the plant's response to light.

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    Auxin

    A plant hormone responsible for cell elongation, a key process in plant growth and development. It moves from the tip of a seedling to its shady side, causing the stem to bend towards light.

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    Plant Growth Methods

    Plants grow in two ways: cell elongation - stretching existing cells, and cell division - creating new cells. These processes involve different hormones and locations within the plant.

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    Frits Went Experiment

    A classic experiment that demonstrated the existence of plant hormones. It involved cutting off the tip of a seedling, placing it on an agar block, and observing the bending of another seedling when the agar block (containing the hormone) is placed on one side.

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    Yoga Plant Demo

    A demonstration that helps understand how auxin stimulates growth on the shady side of a plant. It involves bending a plant, demonstrating the effect of auxin distribution.

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    Auxin: What's its role?

    Auxin is a plant hormone that helps with stem elongation (growing taller), fruit growth, apical dominance (main stem dominance), abscission (leaf shedding), and seed germination.

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    Gibberellins: What do they do?

    Gibberellins are plant hormones involved in stem growth, seed germination, and fruit development. They also play a role in breaking dormancy.

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    Ethylene: What's its effect?

    Ethylene is a gas that acts as a plant hormone. It promotes fruit ripening, inhibits stem elongation, and is involved in leaf senescence (aging).

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    Cytokines: What's their function?

    Cytokines are plant hormones that stimulate cell division. They also help with leaf senescence (aging) and cell growth.

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    Brassinosteroids: What are their roles?

    Brassinosteroids are plant hormones that regulate stem and pollen tube elongation, and vascular tissue differentiation (growth of veins).

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    Cation Exchange

    The process where positively charged ions (cations) are released from clay particles in soil and become available to plant roots. This is driven by the release of hydrogen ions (H+) from root hairs and cellular respiration.

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    Mycorrhizal Associations

    A symbiotic relationship between fungi and plant roots where fungi help plants absorb nutrients and water, while plants provide the fungi with sugars.

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    Rhizobia Bacteria

    Nitrogen-fixing bacteria that live in a symbiotic relationship with legumes, converting atmospheric nitrogen (N2) into a usable form (ammonia) for plants.

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    Nitrogenase

    An enzyme found in nitrogen-fixing bacteria that breaks down the strong triple bond in nitrogen gas (N2), converting it into ammonia (NH3).

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    Essential Nutrient

    A nutrient that a plant absolutely requires for survival and cannot synthesize on its own. It must be obtained from the environment.

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    Low Oxygen Environment for Nitrogen Fixation

    Rhizobia bacteria need a low oxygen environment to fix nitrogen effectively. Legumes provide this by producing a protein called leghemoglobin which binds to oxygen, creating a low oxygen concentration.

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    Water potential

    The potential energy of water in a system. It is influenced by pressure and solute concentration. Water moves from areas of higher water potential to areas of lower water potential.

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    How does water move in the phloem?

    Water moves from the xylem into the phloem when sugar is loaded into the phloem, making the water potential more negative. Then, when the sugar is unloaded at a sink cell, water moves back to the xylem.

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    Girdling a branch

    Removing a ring of bark (which includes the phloem) from a branch. This prevents sugars from moving down to the roots, causing fruit to grow larger and sweeter.

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    Girdling a trunk

    Removing a ring of bark (including the phloem) from the trunk of a tree. This prevents sugars from reaching the roots, causing the tree to eventually die.

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    Sugars move from source to sink

    Sugars are transported from their source (where they are produced, like leaves) to their sink (where they are used or stored, like fruits or roots) through the phloem.

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    Guard Cells

    Specialized cells surrounding stomata (pores on leaves) that regulate gas exchange by opening and closing.

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    How do guard cells open?

    Guard cells take up water, becoming turgid and opening the stomata. This happens because water uptake increases turgor pressure, making the cells swell and open the pore.

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    Pressure Flow Model

    The mechanism that explains how sugars are transported through plants. Sugars move from source (where they're produced) to sink (where they're used) by differences in pressure potential.

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    Monocot vs. Eudicot

    Monocots have one cotyledon (seed leaf) and typically have parallel leaf veins, while eudicots have two cotyledons and usually have netlike leaf veins.

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    Dermal Tissue

    The outer protective layer of a plant, including the epidermis, guard cells, trichomes, and root hairs.

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    Vascular Tissue

    The transportation system of a plant, composed of xylem (water transport) and phloem (sugar transport).

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    Ground Tissue

    The bulk of a plant's body, providing support and storage, and consisting of parenchyma, collenchyma, and sclerenchyma.

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    What are the 3 Basic Plant Tissue Systems?

    Plants have three basic tissue systems: Dermal, Vascular, and Ground. Dermal tissue provides protection, Vascular tissue transports fluids, and Ground tissue provides support and storage.

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    What are sieve tube cells?

    Sieve tube cells are long, narrow cells that form the main transport channels of the phloem, transporting sugars and other nutrients throughout the plant.

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    What are companion cells?

    Companion cells are smaller cells located alongside sieve tube cells. They provide metabolic support to the sieve tube cells, keeping them alive and functional.

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    What is a meristem?

    A meristem is a region of actively dividing cells in plants responsible for growth. They are found at the tips of roots and shoots (apical meristems) and in lateral regions for increasing girth (lateral meristems).

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    What is the cuticle's function?

    The cuticle is a waxy layer covering the outer surface of leaves. It prevents water loss (desiccation) and helps protect the plant from environmental stresses.

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    What is the function of air spaces in leaves?

    Air spaces within the spongy mesophyll layer of leaves facilitate gas exchange, allowing for the uptake of carbon dioxide for photosynthesis and the release of oxygen.

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    What cells are at A?

    The cells at A are palisade mesophyll cells, which are tightly packed and contain many chloroplasts, making them the primary sites of photosynthesis in leaves.

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    What cells are at B?

    The cells at B are spongy mesophyll cells, which are loosely packed and have large air spaces. They facilitate gas exchange with the palisade cells and allow for movement of gases.

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    How do plants grow?

    Plants grow in two ways: by producing new cells through cell division (mainly in meristems) and by expanding the size of existing cells (cell elongation).

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    What are the two ways to grow?

    The two ways plants grow are through cell division (meristems) and cell elongation (expansion).

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    What is cell elongation?

    Cell elongation is the expansion of existing cells, causing the plant to grow in length. It can increase a cell's size by 1000 to 1,000,000 times.

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    What activates development after fertilization?

    Fertilization activates development by triggering changes in the egg, such as increased metabolism, protein synthesis, and a series of rapid cell divisions. These changes are initiated by the entry of a sperm and the subsequent changes in ion fluxes and cytoplasmic pH.

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    Zygote

    The initial cell formed by the fusion of an egg and a sperm during fertilization. It contains the full set of chromosomes (2n) and initiates the developmental process.

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    Blastocyst

    A hollow ball of cells that develops from the zygote. It's formed during early cleavage and implants in the uterus, marking the start of pregnancy.

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    Gastrulation

    A crucial stage of development where the blastocyst forms three distinct layers of cells: endoderm, mesoderm, and ectoderm. These layers give rise to different organs and tissues.

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    Organogenesis

    The developmental process where organs and organ systems are formed from the three germ layers established during gastrulation. It involves cell differentiation and migration.

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    Rotational Cleavage

    A type of cell division where cells divide completely and symmetrically, resulting in a ball of cells.

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    Trophoblast

    The outer layer of cells in the blastocyst, responsible for secreting fluid and forming the blastocoel.

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    Inner Cell Mass

    The inner group of cells in the blastocyst, which will develop into the embryo.

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    Implantation

    The process where the blastocyst burrows into the uterine wall.

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    Epiblast

    The upper layer of the inner cell mass that will form the animal part of the embryo.

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    Hypoblast

    The lower layer of the inner cell mass, which will form extraembryonic tissues.

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    Amniotic Cavity

    The fluid-filled space that forms in the epiblast, creating a protective environment for the embryo.

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    Cell Potency

    The ability of a cell to develop into different cell types. Cells can be classified as totipotent, pluripotent, multipotent, or unipotent, based on their developmental potential.

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    Differential Gene Expression

    The process by which different sets of genes are activated or deactivated in different cell types, leading to specialization.

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    Determination

    The process by which a cell commits to a specific fate, becoming restricted to a particular developmental pathway.

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    Differentiation

    The process by which a cell undergoes structural and functional changes to become a specialized cell type.

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    Gene Cascade

    A series of events where the activation of one gene triggers the activation of other genes, ultimately leading to the development of a specific tissue or organ.

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    Totipotent

    A cell that can differentiate into any cell type, including embryonic cells.

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    Pluripotent

    A cell that can differentiate into most cell types, but not embryonic cells.

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    Multipotent

    A cell that can differentiate into several related cell types.

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    Unipotent

    A cell that can only differentiate into its own cell type.

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    Induction

    A process where one cell type influences another cell's fate.

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    What is an action potential?

    A rapid change in electrical potential across a neuron's membrane, allowing information to travel quickly along the neuron.

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    What are voltage-gated sodium channels?

    These protein channels in neuron membranes open in response to a change in voltage, allowing sodium ions (Na+) to rush into the neuron.

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    What is the role of the axon hillock?

    The specialized region of a neuron where action potentials are initiated. It has a high density of voltage-gated sodium channels.

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    What is depolarization?

    The process where the inside of a neuron becomes more positive due to the influx of sodium ions (Na+).

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    How does an action potential propagate down the axon?

    As an action potential travels down the axon, it triggers the opening of voltage-gated sodium channels in the adjacent region, creating a chain reaction of depolarization.

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    Saltatory Conduction

    A type of rapid nerve impulse conduction where the action potential jumps from one node of Ranvier to the next, skipping over the myelinated sections of the axon.

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    Myelin Sheath & Conduction Speed

    The myelin sheath, a fatty covering around axons, increases the speed of action potential conduction by reducing ion leakage and allowing for saltatory conduction.

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    Neuron Size & Conduction Speed

    Larger neurons have a faster conduction speed because they offer less resistance to the flow of ions during action potential propagation.

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    Resting Membrane Potential

    The electrical potential difference across the plasma membrane of a neuron when it is not transmitting an impulse.

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    Synapse

    The junction between two neurons, where a signal is transmitted from one neuron to the next via neurotransmitters.

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    Neurotransmitter

    A chemical messenger released by a neuron at a synapse, that binds to receptors on the postsynaptic cell to transmit a signal.

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    Botox Effect

    Botox inhibits the release of neurotransmitters from vesicles by preventing them from binding to the cell membrane, effectively blocking the transmission of signals.

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    Inhibitory & Excitatory Drugs

    Inhibitory drugs reduce the likelihood of a postsynaptic neuron firing an action potential, while excitatory drugs increase the likelihood.

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    Exocytosis

    The process by which vesicles containing neurotransmitters fuse with the cell membrane and release their contents into the synaptic cleft.

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    Tidal Volume

    The amount of air inhaled or exhaled during a normal breath.

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    Vital Capacity

    The maximum amount of air that can be exhaled after a deep inhalation.

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    Residual Volume

    The amount of air remaining in the lungs after a forceful exhalation.

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    Interpleural Membrane Pressure

    The pressure in the space between the lungs and the chest wall. It becomes more negative during inhalation and less negative during exhalation.

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    Oxygen Dissociation Curve Shift

    The oxygen dissociation curve shifts left when hemoglobin has a higher affinity for oxygen, meaning it binds oxygen more easily and releases it less readily. This occurs in high-altitude environments, fetuses, and diving/flying animals.

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    Cooperative Binding

    Hemoglobin's binding of one oxygen molecule increases its affinity for subsequent oxygen molecules. This is why the oxygen dissociation curve is sigmoidal (S-shaped).

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    Fetal Hemoglobin Shift

    Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin, enabling the fetus to extract oxygen from the mother's blood.

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    Llama Hemoglobin

    Llamas, adapted to high altitude, have hemoglobin with a higher affinity for oxygen.

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    Diving/Flying Animals

    Animals that dive deep or fly high also have left-shifted oxygen dissociation curves to better extract oxygen in low-oxygen environments.

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    COVID-19 Hemoglobin Shift

    Hemoglobin in COVID-19 patients may shift left, possibly to preserve oxygen for vital organs.

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    Alveoli: Gas Exchange Site

    Alveoli, tiny air sacs in the lungs, are where oxygen diffuses from the air into the blood and carbon dioxide moves from the blood into the air.

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    Surfactant's Role

    Surfactant, a fluid lining the alveoli, prevents them from collapsing by reducing surface tension.

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    Pleural Membrane

    The pleural membrane is a double-layered membrane that surrounds each lung, helping to maintain negative pressure for breathing.

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    Breathing Mechanism

    Breathing is achieved by creating a pressure difference between the lungs and the environment. This pressure difference is controlled by changes in lung volume and negative pressure in the intrapleural space.

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    First Degree AV Block

    A type of heart block where the electrical signal from the atria to the ventricles is slowed down, but not completely blocked. This results in a prolonged PR interval on the ECG.

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    What is the foramen ovale?

    A hole between the right and left atria in a fetal heart that allows oxygen-rich blood to bypass the lungs and directly reach the brain.

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    What is the function of the heart?

    The heart is the muscular pump that circulates blood throughout the body, delivering oxygen and nutrients to the tissues and removing waste products.

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    What is blood pressure?

    The force exerted by blood against the walls of arteries as the heart pumps blood throughout the body.

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    How do beta blockers lower blood pressure?

    Beta blockers reduce heart rate by decreasing the binding of epinephrine (adrenaline) to SA node muscle cells, leading to lower cardiac output and reduced blood pressure.

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    Blood Pressure and Total Area

    Blood pressure is inversely proportional to the total area of the blood vessels. This means that as the total area of blood vessels increases, blood pressure decreases.

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    Blood Pressure in Arteries, Veins, and Capillaries

    Blood pressure is higher in arteries and veins compared to capillaries due to the smaller total area in these larger vessels, according to the inverse relationship between pressure and area.

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    Gap Junctions in Cardiac Muscle

    Gap junctions in cardiac muscle allow the electrical signal to travel quickly through the entire heart, ensuring synchronized contraction of muscle cells.

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    The Heart Pump: Systole and Diastole

    Systole refers to the contraction phase of the heart, while diastole represents the relaxation phase. The heart pumps blood during systole and fills with blood during diastole.

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    The Heart's Pumping Cycle

    The heart pumps blood through a four-step process: 1) Relaxation of atria and ventricles, 2) Atrial contraction, 3) Ventricular contraction, 4) Return to relaxation.

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    SA Node: Pacemaker of the Heart

    The SA node is a group of specialized cells in the heart that initiates the electrical impulse for each heartbeat, making it the pacemaker of the heart.

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    Electrical Conduction System of the Heart

    The electrical conduction system of the heart is a network of specialized cells responsible for generating and transmitting electrical impulses that control the heartbeat.

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    Key Concepts for Circulation

    Key concepts for understanding circulation include types of circulatory systems (e.g., open vs. closed), the anatomy of the heart and blood vessels, the electrical conduction system, and blood pressure.

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    Closed Circulatory System: The Heart and Vessels

    A closed circulatory system involves blood contained within vessels and transported by a heart. The heart acts as the pump, and vessels (arteries, veins, capillaries) act as the plumbing for blood flow.

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    Types of Circulatory Systems

    There are different types of circulatory systems, including open systems where blood directly bathes tissues and closed systems where blood is enclosed within vessels. Humans have a closed circulatory system.

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    Osmoregulation

    The process by which organisms maintain a stable internal water balance and solute concentration, despite environmental changes.

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    Kidney Structure: Cortex

    The outer layer of the kidney, containing nephrons (functional units of the kidney) and blood vessels.

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    Filtrate

    Fluid that passes through the glomerulus in the kidney, containing water, ions, and small molecules.

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    Secretion in Excretory Organs

    The process by which cells in an excretory organ actively pump substances into the filtrate, increasing its concentration.

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    Juxtamedullary Nephrons

    Specialized nephrons found in mammals and birds, with a long Loop of Henle that extends deep into the medulla, enabling concentrated urine production.

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    Counter-current Multiplier

    The mechanism by which the loop of Henle concentrates urine by actively transporting salt out of the ascending limb and allowing water to diffuse out of the descending limb.

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    Ascending Limb Function

    The ascending limb of the loop of Henle actively transports salt out of the filtrate, creating a high salt concentration in the interstitial fluid of the medulla.

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    Descending Limb Function

    The descending limb of the loop of Henle is permeable to water but not salt, allowing water to diffuse out of the filtrate and concentrate the remaining solution.

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    Vasa Recta Role

    The vasa recta blood vessel removes water and excess salt from the interstitial fluid of the medulla, preventing the concentration gradient from being diluted.

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    Urine Concentration Location

    Urine is technically concentrated in the collecting duct, not the loop of Henle. The loop of Henle creates the concentration gradient that allows water to diffuse out of the collecting duct.

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    What is the role of the loop of Henle in urine concentration?

    The loop of Henle acts as a counter-current multiplier, creating a concentration gradient in the interstitial fluid of the medulla that allows water to diffuse out of the collecting duct, concentrating urine.

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    Why does it make sense to concentrate the filtrate in the descending limb?

    Concentrating the filtrate in the descending limb of the loop of Henle helps to maximize water reabsorption and minimize urine output.

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    How does the concentration gradient in the interstitial fluid of the medulla get established?

    The concentration gradient in the interstitial fluid of the medulla is established by the active transport of salt out of the ascending limb of the loop of Henle.

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    What is the purpose of the vasa recta?

    The vasa recta serves to maintain the concentration gradient in the interstitial fluid of the medulla by removing excess water and salt.

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    Where does urine go after leaving the collecting duct?

    After leaving the collecting duct, urine travels through the renal pelvis and ureter to the bladder for storage and eventual excretion.

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    Field Metabolic Rate

    The average metabolic rate of an organism over a period of time, like a day, week, or season. It reflects how much energy the organism uses in its natural environment.

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    Log-Log Scale

    A type of graph scale where both the x-axis and y-axis have logarithmic values. This allows for comparing a wide range of values, from very small to very large.

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    Ectotherms' Energy Budget

    Ectotherms, like reptiles, have a lower metabolic rate compared to endotherms like birds and mammals. This means they require less energy because they rely on external heat sources for temperature regulation.

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    What are the units for mass-specific metabolic rate?

    Mass-specific metabolic rate is typically measured in units of energy per unit of mass per unit of time. Common units include kcal/daykg or Joules/secondgram.

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    Lower Critical Temperature (LCT)

    The environmental temperature below which an endothermic animal must increase its metabolic rate to maintain a constant body temperature.

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    Thermal Neutral Zone

    The range of environmental temperatures where an endothermic animal can maintain its body temperature without increasing its metabolic rate.

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    Setpoint

    The desired or target value for a physiological variable (like body temperature) that the body tries to maintain.

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    How does body size affect metabolic rate?

    Smaller animals have a higher mass-specific metabolic rate than larger animals. This means smaller animals use more energy per unit of body mass. However, larger animals have a higher whole body metabolic rate.

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    How does metabolic rate change with environmental temperature?

    Endotherms maintain a stable body temperature within a range of environmental temperatures. At temperatures below the lower critical temperature, metabolic rate increases to generate heat. At temperatures above the thermal neutral zone, metabolic rate increases to dissipate heat. Ectotherms generally have lower metabolic rates and rely on external sources of heat to regulate their body temperature.

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    Epithelial Tissue Function

    Epithelial tissues cover surfaces, line cavities, and form glands. Their main functions include secretion (releasing substances), absorption (taking in substances), and protection.

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    Connective Tissue Function

    Connective tissues provide support, bind different tissues together, and protect organs. They're made of cells embedded in an extracellular matrix that can be liquid, jelly, or solid.

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    Muscle Tissue Function

    Muscle tissue is specialized for contraction, enabling movement, heat production, and maintaining posture.

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    Nervous Tissue Function

    Nervous tissue is responsible for communication and information processing throughout the body. It includes neurons, which transmit signals, and glial cells, which support neurons.

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    Types of Muscle Tissue

    There are three main types of muscle tissue: 1) Cardiac (heart): involuntary, striated 2) Skeletal (attached to bones): voluntary, striated 3) Smooth (found in organs): involuntary, non-striated

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    Form and Function

    The idea that an organism's structure (form) is directly related to its specific role or activity (function).

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    Animal Tissues

    Four main types of tissues in animals: epithelial, connective, muscle, and nervous. Each has a specific structure and function.

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    Metabolism

    The sum of all chemical reactions that occur within an organism. This includes breaking down food for energy (catabolism) and building complex molecules (anabolism).

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    Spearers and Smashers

    Two types of mantis shrimp appendages: spearers for stabbing, smashers for breaking.

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    What does a high surface area to volume ratio mean for an organism?

    A high ratio suggests that the organism has a larger surface area relative to its volume. This facilitates efficient exchange of materials with the surroundings.

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    How does homeostasis relate to metabolism?

    Metabolism is responsible for generating the energy needed for maintaining homeostasis. Processes like temperature regulation, nutrient transport, and waste removal are all driven by metabolic reactions.

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    What are the advantages and disadvantages of a high surface area to volume ratio?

    Advantages: Efficient exchange of materials, like oxygen and nutrients. Disadvantages: Increased energy expenditure, potential for rapid heat loss.

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    What are some examples of how form and function are related in animals?

    Examples include: beaks adapted for specific food types, wings for flight, camouflage patterns for hiding, and digestive systems specialized for specific diets.

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    Heat Loss in Animals

    Small animals tend to lose heat quickly due to their high surface area to volume ratio. Large animals have a harder time losing heat because they have a lower surface area to volume ratio.

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    Plant Structures with High Surface Area to Volume Ratio

    Plants have structures like roots and leaves with a high surface area to volume ratio. This helps maximize their ability to absorb water and nutrients (roots) and capture sunlight (leaves).

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    Key Concepts for Chapter 38/39

    The core concepts of these chapters relate to the basic principles of animal structure and function, including the relationship between form and function, the importance of surface area to volume ratios, the concept of homeostasis, and the basics of animal metabolism.

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    Why is surface area:volume ratio important?

    This ratio dictates how efficiently cells, organs, and organisms can exchange materials with their environment. It plays a key role in processes like nutrient uptake, waste removal, and gas exchange.

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    How does size affect surface area:volume ratio?

    As an object gets larger, its surface area increases at a slower rate than its volume. This means larger organisms have a lower surface area to volume ratio.

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    What are the four types of tissues?

    Animal tissues are classified into four main types: epithelial, connective, muscle, and nervous.

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    Epithelial Tissue

    This tissue forms linings and coverings of organs and cavities. It provides protection, absorption, secretion, and filtration.

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    Connective Tissue

    This tissue provides structural support, binds tissues together, stores energy, and transports substances.

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    Muscle Tissue

    This tissue is specialized for contraction and movement.

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    Nervous Tissue

    This tissue is responsible for communication within the body using electrical signals.

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    Form follows function

    The structure of an organism or its parts is directly related to its function. This principle applies at all levels of biological organization.

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    Study Notes

    Bio 20B Study Notes

    • Surface Area to Volume Ratio:

      • Students can identify the shape of the SA:Vol curve vs. body size.
      • Students can plot SA and Vol separately.
      • Given values, students can calculate SA:Vol.
      • Students can apply SA:Vol to a body (volume=heat production; surface area=heat loss).
      • Students can differentiate between whole-body metabolic rate and mass-specific metabolic rate.
      • Students identify and label units on graphs for SA:Vol, metabolic rate, and mass.
      • Students can calculate these variables and graph them.
      • Students can describe the relationship visually.

    • Bioenergetics and Metabolism:

      • Students should identify 4 animal tissue types and provide examples.
      • Students need to differentiate between regulatory and conforming strategies.
      • Students can create graphs of body temperature vs. environmental temperature (regulator vs. conformer).
      • Students can define and give examples of endotherms and ectotherms.
      • Endotherms get heat from metabolism; ectotherms get heat from the environment.
      • Students should understand homeostasis is not limited to temperature.

    • Digestive System:

      • Describe major organs in the digestive system and where specific fuels are digested and absorbed.
      • Understand the difference between digestion (breaking polymers into monomers) and absorption (crossing cell membranes).

    • Osmoregulation and Excretory System:

      • Animals break down nitrogenous waste products into different products with varying energy expenditure and water-saving properties.
      • Different osmotic adaptations depend on the environment.
      • Students understand the terms hypoosmotic and hyperosmotic.
      • Given an organism and its environment, predict water movement and organismal adaptations.
      • Describe the nephron and urine formation steps.
      • Explain why fish cannot concentrate urine beyond body fluid osmolarity, but birds and mammals can.
      • Explain how alcohol and ADH affect urine output.

    • Circulatory System:

      • Students need to know the difference between open and closed circulatory systems (single/double circuits).
      • Students should draw and understand the contraction cycle and EKG.
      • Students need to understand the heart's pacemaker and electrical conduction system (AV node, bundle of His).
      • Students should know the heart anatomy and blood vessels. Trace blood flow in the mammalian heart.
      • Students should know blood pressure equation (cardiac output, TPR).

    • Respiratory System:

      • Students should describe negative pressure breathing and respiration anatomy in mammals.
      • Describe the components of blood and red blood cell anatomy.
      • Describe hemoglobin as a molecule and its purpose.
      • Draw and interpret an oxygen-hemoglobin dissociation curve (shifts).
      • Explain the effect of conditions and cooperate with hemoglobin.
      • Explain sickle cell anemia's impact on oxygen transport.
      • Describe fetal hemoglobin.
      • Describe altitude's effects.

    • Nervous System: -Diagram basic neuron anatomy. -Understand the blood-brain barrier and its role in the nervous system. -Understand the role of myelin. -Understand the purpose of an action potential. -Explain electrochemical gradients and action potential establishment.

      • Accurately describe the five components of the action potential.
      • Describe why an action potential travels in one direction. -Graph an action potential, and explain the spatial aspect. -Understand neurotransmitters and their general function. -Explain the mechanisms of action of drugs.

    • Musculoskeletal System:

      • Describe the neuromuscular junction and the role of acetylcholine. -Describe muscle anatomy (thick/thin filaments). -Describe sliding filament theory. -What shortens during muscle contraction? -What role does calcium play in muscle contractions?

    • Animal Development: -Describe determination and differentiation. -Explain differential gene expression, cytoplasmic segregation, and induction (DGE). -Explain a morphogen gradient. -Describe morphogen gradient in Drosophila. -What are hox genes? -Describe an organizer. -Differentiate between induced pluripotent stem cells and embryonic stem cells.

    • Plant Structure and Function: -List plant cell types/tissues and give their properties. -Diagram cross-sections of plant parts (leaf, stem, root). -Know the differences in plant tissues in monocots and eudicots. -Describe the function and location of meristems. -Describe secondary growth (lateral meristems). -Explain why plants rely more on expansion than division.

    • Water and Sugar Transport: -Use water potential equation. -Describe components of water potential (solute and pressure). -Describe guard cell function & water potential's role in opening/closing stomates. -Describe the transpiration-cohesion-tension theory. -Describe water transport in plants. -Explain the difference between apoplastic and symplastic movement (and relative speeds).

    • Plant Nutrition: -State where plant carbon comes from. -Define mutualism (e.g., mycorrhizae). -Explain nitrogen fixation's difficulty for plants.

    • Plant Growth and Regulation: -Identify where light is detected in plants. -Describe the structures involved in light detection and the structure of pigments. -Explain the Darwin/Went experiments, and Thimann's discoveries. -Explain auxin's one-way movement (polar transport) -Explain auxin's role in cell growth (acid growth hypothesis). -Describe the influence of proton pumps, water potential, and transcription on auxin.

    • Photosynthesis: -State the overall reactants and products of photosynthesis. -Describe light-dependent and Calvin cycle reactions.
      -Explain the flow of electrons in photosystems.
      -Describe the role of chlorophyll. -Explain why a photosystem is like an antenna. -Explain the role of the reaction center -Describe the role of rubisco.

    • Plant Reproduction: -Describe alternation of generations.

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    Description

    Test your understanding of surface area to volume ratios and metabolic processes in animals. This quiz covers key concepts like bioenergetics, tissue types, and the physiological strategies of endotherms and ectotherms. Prepare to plot graphs and differentiate between various metabolic rates.

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