Biology EOC Review Notes PDF

Biology EOC Review IMPORTANT NOTES! ○ This set of review materials covers the Biology EOC Standards covered in our course in a general sense, but I cannot guarantee that it covers every single thing we have discussed in the class ○ Topics may be listed in different orders from...

Biology EOC Review IMPORTANT NOTES! ○ This set of review materials covers the Biology EOC Standards covered in our course in a general sense, but I cannot guarantee that it covers every single thing we have discussed in the class ○ Topics may be listed in different orders from how they were covered in class ○ Use this as a tool for studying the course as a whole, however you should review all notes in the class Google Drive in order to study all units in full detail as well as reviewing your study guide, old notes and assignments, and practice EOC questions Scientific Method Vocabulary ○ Hypothesis: A proposed explanation for an observation based on evidence ○ Independent Variable: Variable that does not change during an experiment (Ex. Time) ○ Dependent Variable: Variable whose value depends on the value of the independent variable ○ Control Group: A group in an experiment that is not changed ○ Used as a benchmark to ensure that any observations in the experiment are truly due to the changes made in the experiment Eight Characteristics of Life 1. Made of Cells 2. Obtains and Uses Energy 3. Grows and Develops 4. Maintains Homeostasis 5. Responds to Stimuli 6. Based on a Universal Genetic Code (DNA) 7. Reproduces Independently 8. Evolves Over Time Topic 1: Molecular Biology ○ Bio 4.1 Biological Molecules ○ Bio 4.1.1 Structure and function of organic compounds ○ Bio 4.1.2 Proteins and protein synthesis ○ Bio 4.1.3 Enzymes ○ Bio 4.2 Biochemical processes and Energy use in the cell ○ Bio 4.2.1 Photosynthesis and cellular respiration ○ Bio 4.2.2 Energy is necessary for homeostasis Organic Molecules ○ Contain the elements Carbon (C) and Hydrogen (H) ○ Oxygen (O) is also very common ○ Four major groups: ○ Carbohydrates ○ Lipids ○ Proteins ○ Nucleic Acids Carbohydrates ○ Structure/monomer/subunit/basic building block: Monosaccharide ○ Function: Energy source and structure ○ Examples: ○ Glucose (C6H12O6)-blood sugar ○ Cellulose- plant cell walls ○ Starch- Energy storage for plants ○ Glycogen- Energy storage in mammals’ liver ○ Tests: ○ Glucose-Benedict’s solution (when heated turns orange/green) ○ Starch- Iodine solution (turns blue black color) ○ Words ending in –ose: Sugars Lipids ○ Structure: 3 fatty acids and 1 glycerol ○ Function: long term energy storage, protection, and insulation ○ Examples: Fats, phospholipids (cell membrane structure) and steroids (embedded in cell membrane) ○ Test: Brown paper bag absorbs Lipid vs.. Water Nucleic Acids ○ Monomer/subunit/basic building block: Nucleotide (composed of a sugar, phosphate group, and nitrogen base) ○ Function: Store genetic information ○ Examples: DNA and RNA Proteins ○ Monomer/subunit/basic building block- amino acids (20 different amino acids) ** all have same basic structure, including an amino group and carboxyl group. However, all have different “R” group which determines shape which determines function. ** Proteins whose shape has been changed have been denatured ○ Function- building and repairing cells, communication, transport, gene expression, and regulation ○ Test- Biurets ○ Examples: ○ Insulin-regulates blood sugar ○ Enzymes-speed up chemical reactions ○ Hemoglobin- carries oxygen in blood Proteins ○ Structural-forming a part of the cell membrane; build things ○ Keratin in nails, horns, claws ○ Chitin in insect exoskeletons ○ Functional- Used for a specific purpose ○ hormones (chemical messengers) ○ enzymes Enzymes ○ Organic catalysts that speed up chemical reactions by lowering activation energy ○ Energy required to begin a reaction ○ Specific to a reaction; “lock and key method” ○ Proteins ○ Reusable ○ Affected by temperature and pH; shape is altered in high temperature and extreme pH ○ End in “-ase” Photosynthesis ○ The way plants make their own food (autotrophs) ○ Reactants: Water, Carbon Dioxide, and Sun ○ Products: Glucose and Oxygen ○ Light+H2O+CO2→C6H12 O6+O2 ○ Occurs in the chloroplast Photosynthesis Continued ○ Plants take in water through their roots and take in carbon dioxide through holes in their leaves called stomata Aerobic Respiration ○ Requires Oxygen ○ Used to release energy (ATP) for use by the cell ○ Reactants: Glucose and oxygen ○ Products: Water and Carbon Dioxide ○ C6H12O6+O2→H2O+CO2 ○ Occurs in the mitochondria ○ Chemical equation is the inverse of photosynthesis ○ 36-38 ATP per glucose; very efficient Anaerobic Respiration ○ Also known as fermentation ○ No Oxygen required ○ Used to release energy, but not as efficient as aerobic respiration (Only 2 ATP per glucose) ○ Products include CO2 and lactic acid or alcohol ○ Two Types: ○ Alcoholic Fermentation (yeast/beer) ○ Lactic Acid Fermentation (muscle fatigue/cramps) ATP – Energy Storage Molecule ○ Adenosine triphosphate – Contains three phosphates ○ Energy is stored in the bonds between phosphates ○ Bonds are broken (cleaved) to release energy, leaving behind ADP with two phosphates ○ Used in maintaining homeostasis ○ Can be used for quick energy by the cell ○ Can be re-energized like a rechargeable battery from ADP back to ATP ○ Energy acquired in respiration re-attaches loose phosphates Homeostasis The maintenance of a stable, internal environment ○ Sweating - Reduce temperature in heat ○ Shivering - Raise temperature in cold ○ Buffers - Chemicals that resist changes in pH found in blood ○ Enzyme and hormone levels in the body ○ Insulin regulates blood sugar levels ○ Excretion of toxic byproducts of metabolism Molecular Biology Questions 1. Glucose is blood sugar and insulin helps to regulate it. From which organic compounds do glucose and insulin belong? 2. Plants and animals must store carbohydrates to use for later. Which carbohydrate is used for storage in plants? Which carbohydrate is used for storage in animals? 3. Which carbohydrate is found in plant cell walls and is indigestible for mammals and other animals? 4. Which organic compound would become your energy source if you were without food for a long period of time? 5. The functional units of DNA are ___________________. 6. What makes the 20 different amino acids different? How does this contribute to their function? 7. How do enzymes speed up reactions? 8. How many substrates can one enzyme fit with? What type of analogy can be used to explain this? 9. What happens to the enzymes in your body if your temperature is too high 10. Which organelle is the site of photosynthesis? 11. What type of organisms can use photosynthesis? 12. Which organelle is the site of respiration? 13. What type of organisms can use respiration? 14. Which two compounds are created at the end of photosynthesis and are used at the beginning of aerobic respiration? 15. Which anaerobic process is responsible for producing ATP in the absence of oxygen? 16. Which compounds builds up in your muscles after strenuous exercise and causes them to feel sore? 17. Which compound is produced by plants and yeast during anaerobic respiration? 18. Why is aerobic respiration considered the ideal method of producing ATP? 19. Why is ATP necessary for all living things? Topic 2: Structure and Function of Living Organisms ○ Bio 1.1 Structures and functions of cells and their organelles ○ Bio 1.1.1 Eukaryotic cells’ organelles (nucleus, plasma membrane, cell wall, mitochondria, vacuoles, chloroplasts, and ribosomes) ○ Bio 1.1.2 Prokaryotic vs. Eukaryotic cells ○ Bio 1.1.3 Instructions in DNA lead to cell differentiation and result in cell specialization ○ Bio 1.2 Cell as a Living System ○ Bio 1.2.1 Homeostasis ○ Bio 1.2.2 Cell Cycle (Interphase, Mitosis, and Cytokinesis ○ Bio 1.2.3 Specific Cell Adaptations Cell Theory 1. All living things are composed of one or more cells a. Unicellular or Multicellular 2. The cell is the basic unit of life 3. All cells come from existing cells a. Mitosis or Meiosis Types of Cells Prokaryotes Eukaryotes ○ Simple, no ○ Membrane-bound membrane-bound organelles organelles ○ Contain nuclei ○ No nuclei ○ Plants, animals, protists, ○ Bacteria only (unicellular) fungi (unicellular and multicellular) ○ Smaller than eukaryotes ○ Contain: Circular DNA strands (plasmids), ribosomes, and a plasma membrane Nucleus/Nucleolus ○ Nucleus (Membrane bound) ○ Contains chromosomes ○ Stores genetic information ○ Nucleolus ○ Dense region inside the nucleus ○ Synthesizes ribosomes Mitochondria ○ Energy producing membrane-bound organelle ○ “Powerhouse of the cell” ○ Produces energy in the form of ATP ○ Site of Aerobic/cellular respiration (Occurs on membrane) ○ Highly folded interior increases surface area to increase energy production during cellular respiration Chloroplast ○ Membrane-bound ○ Site of photosynthesis: the way plants make their food-autotrophs ○ Use sunlight, water, and carbon dioxide to produce oxygen and glucose ○ Plant cells, plant-like protists, and some bacteria ○ Contains the green pigment chlorophyll ○ Absorbs energy from sunlight Vacuole ○ Membrane-bound storage organelle for excess materials ○ Food particles, water, waste products, etc. ○ Plant cells usually contain one large, central vacuole ○ Animal cells typically contain several smaller vacuoles Ribosomes ○ Small, protein-synthesizing organelles ○ NOT membrane-bound ○ Found in prokaryotes and eukaryotes Cell (Plasma) Membrane ○ Surrounds the cell ○ Regulates what enters/leaves the cell ○ Semipermeable ○ Helps maintain homeostasis (stable internal balance) ○ Made of phospholipids with embedded proteins Cell Wall ○ Found in plants and bacteria ○ Surrounds the cell (Outside the cell membrane) and provides support and protection ○ Made of cellulose in plants ○ Carbohydrate sugar Interaction of Organelles ○ Ex: DNA from the nucleus codes for proteins, which are assembled by ribosomes and are then used as enzymes for energy production in the mitochondria Cell Specialization ○ Cells develop to perform specific functions; structure determines function ○ Regulated by genes Formation of Multicellular Organisms ○ Begin as undifferentiated masses of cells ○ DNA variation & gene activity determines differentiation of cells ○ Only specific parts of DNA activated ○ All cells contain same DNA in organism ○ Genetic instructions influenced by cell’s environment and past history Cell to Cell Communication ○ Chemical Signals (hormones) can be sent from one cell to another ○ Receptor proteins on the plasma membrane receive the signal Stem Cells ○ Unspecialized cells that continually reproduce themselves (self-renewal) and have the ability to differentiate into one or more types of specialized cells ○ Embryonic: Can differentiate into any cell type ○ Adult stem cells: Found in bone marrow, limited differentiation Diffusion ○ Spontaneous movement of particles from high concentration to low concentration across a membrane ○ Form of Passive Transport ○ No energy required ○ Moves “down concentration gradient” Osmosis ○ Diffusion of water across a membrane ○ Passive transport ○ NO ENERGY ○ Moves with concentration gradient ○ High to low concentration ○ Example: Food color in water Facilitated Diffusion Passive transport of molecules that are too large to pass through the membrane by themselves ○ Use a Channel Protein to pass through the membrane ○ “Facilitate” means help Active Transport ○ Particles moving against the concentration gradient which REQUIRES ENERGY (ATP) ○ Moves from low concentration to high concentration ○ Example: Riding back up the hill requires energy ○ Energy needed to maintain homeostasis within organisms ○ Example: Cell getting rid of toxins; concentrating food particles within cell Solutions ○ Isotonic: Concentration of solutes in the cell=concentration of solutes outside the cell ○ Hypertonic: Water is greater inside the cell than outside the cell; solutes outside the cell are greater than solutes inside the cell; water exits the cell and the cell shrivels ○ Hypotonic: Solutes outside the cell are less than solutes inside the cell; water moves into the cell and the cell swells and possibly bursts  Solutions Isotonic Hypotonic Hypertonic Concentration is the Concentration is Concentration is same on both sides of higher inside of the higher outside of the the cell membrane cell cell Movement of water is Water moves into the Water moves out of the same in and out cell; cell swells and the cell; cell shrivels of a cell may burst Sodium-Potassium Pump Cell Cycle ○ Interphase: cell spends the most time (G1 (growth), S (DNA and chromosomes replicate), G2 (Growth and preparation for division) ○ Mitosis: makes body cells; asexual; parent and offspring identical ○ Cytokinesis: cytoplasm divides and 2 new cells formed Phases of Mitosis (PMAT) ○ Prophase: P for “Preparation” (chromosomes become visible, nucleus disappears) ○ Metaphase: M for “Middle” (chromosomes line up in the middle of the cell) ○ Anaphase: A for “Apart” (sister chromatids separate from each other) ○ Telophase: T for “Two” (nuclei reappear and cleavage furrow forms) Cytokinesis: “cytoplasm divides” Results in 2 diploid identical cells (parents identical to daughter cells) Binary Fission (Bacterial Division) Specific Cell Adaptations ○ Amoeba ○ Paramecium ○ Contractile vacuole ○ Cilia ○ Ejects excess water ○ Short, hair-like ○ Pseudopods structures used for locomotion ○ Movement ○ Euglena ○ Flagella ○ Long, tail-like fibers used for movement ○ Eyespot ○ Light-sensitive cells used for phototaxis Topic 2 Questions 1. What quality of the nucleus allows it to be in charge of all cell processes? 2. Which cell organelle is flexible due to its arrangement of phospholipids? 3. What type of organisms have cell walls? 4. What is the function of the folds within the mitochondria? 5. What three things regarding cell organelles are different between plant and animal cells? 6. Do prokaryotes have ribosomes? Why? 7. What is the only living thing on Earth that is made of a prokaryote cell? 8. What is the name of the circular DNA that prokaryotes have? 9. If all cells have the same DNA, why are they not the same? 10. Why does the body need different types of cells? Give some examples of different cells. 11. What are cells called that do not have a specific job yet? Define homeostasis 13. What is the difference between diffusion and osmosis? 14. If a cell is placed in salt water, what will happen to the cell? 15. If a cell is placed in pure water, what will happen to the cell? 16. What is necessary for the process of active transport to occur? 17. In which part of the cell cycle are chromosomes copied? 18. In which part of the cell cycle do cells spend the most time? 19. What phase/term refers to division of the nucleus and chromosomes? 20. When are two new cells formed? 21. What is the function of the contractile vacuole? 22. What type of organisms have an eyespot? 23. Describe the cilia, flagella, and pseudopods in terms of movement Topic 3: Ecosystems ○ Bio 2.1 Interdependence of Living Organisms ○ Bio 2.1.1 Water, Carbon, Nitrogen, and Oxygen Cycles ○ Bio 2.1.2 Behavioral, Structural, and Reproductive Adaptations ○ Bio 2.1.3 Interactions among Organisms ○ Bio 2.1.4 Ecosystems ○ Bio 2.2 Human Impact ○ Bio 2.2.1 Human Activities ○ Bio 2.2.2 Sustainability  Ecology ○ Study of interactions between organisms and their environments ○ Collection of abiotic (nonliving) and biotic (living or produced by living) factors in an area ○ Together they influence growth, survival, and productivity of an organism Symbiotic Relationships ○ Symbiosis: close and permanent relationship between members of different species ○ Mutualism (+,+) ○ Both benefit ○ Example: bees and flowers both benefit from pollination ○ Parasitism (+,-) ○ One benefits and other harmed ○ Example: Ticks and humans, mistletoe and trees ○ Commensalism (+/0) ○ One benefits, other unaffected ○ Example: Sharks and remora Predation ○ Predator: hunter; eats prey ○ Prey: being hunted or eaten ○ Evolve in response to one another ○ Predation helps maintain stability within an ecosystem by keeping population numbers in check Predator-Prey Relationship ○ Predators eat prey and maintain the health of prey populations. ○ The predators eat old, sick, weak, and injured in prey populations. ○ As the population of the prey increases, the predator population will increase. ○ As the predators increase, the number of prey decrease. Carbon Cycle ○ Carbon cycles through an ecosystem through: ○ Atmosphere: CO2 ○ Photosynthesis: CO2 enters plants and plants use to make glucose ○ Decomposition: Plants die, buried as fossil fuels ○ Humans burn fossil fuels and CO2 enters atmosphere ○ Climate change: CO2 is a greenhouse gas; traps heat in atmosphere ○ Cellular Respiration: Animals eat plants and carbon passes to consumers and then back into the atmosphere through respiration; Humans breathe out CO2 and breathe in O2 Nitrogen Cycle ○ Nitrogen necessary because it is a key component of amino acids (proteins) and nucleic acids (DNA) ○ 78% of air is nitrogen (unusable form for plants and animals) ○ Plants receive nitrogen from the soil, animals obtain it by eating plants ○ Nitrogen fixing bacteria converts nitrogen into a usable form (ammonia) ○ Nitrogen is broken down and returned to the atmosphere by bacteria, fungi, and other microorganisms Food Chains ○ Show the flow of energy from one organism to another organism Food Webs ○ System of interlocking and independent food chains that show all feeding relationships in an ecosystem ○ Autotrophs referred to as producers ○ Heterotrophs referred to as consumers Energy Pyramids ○ Ultimate source of energy- Sun (radiant energy) ○ Radiant energy is converted to chemical energy by producers ○ Chemical energy converted to heat energy ○ Trophic Levels - Steps in a food chain/web ○ Energy passes from one organism to another up trophic levels ○ About 10% of the energy at one level passes to the next and other 90% lost as heat Life Functions ○ Transport-how organisms get what they need to their cells ○ Plant Vascular Tissues: Xylem (water) and phloem (sugar/glucose) example: tree ○ Non-vascular plants: (Moss) do not have a xylem or phloem (no true roots and live in moist areas) and are in close contact with the water and will never grow more than a few inches off the ground ○ Insects, amphibians, and mammals possess circulatory systems with blood vessels to transport needed materials Vascular Plant Structures ○ Xylem-transports water (up from roots to leaves) ○ Phloem-transports sugar (down from leaves to roots) Life Functions ○ Excretion-how organisms get rid of waste ○ Amphibians and mammals- urinary system with kidneys to remove nitrogen; kidneys: regulate water balance, salt, and pH ○ Plants-holes in their leaves called stomata that are used to excrete wastes such as oxygen produced during photosynthesis ○ Plants lose water from stomata during transpiration Life Functions ○ Respiration- how organisms take in and release gases ○ All living things respire to produce ATP using oxygen within the mitochondria of cells ○ Plants take in and release gases through the stomata on their leaves ○ Amphibians and mammals have lungs used for taking in oxygen. ○ Single celled organisms such as bacteria and protist use diffusion for taking in gases Life Functions ○ Nutrition-how organisms get nutrition/break down and absorb foods ○ Autotrophs/producers: make their own food through photosynthesis (ex: plants) ○ Heterotrophs/consumers: get food from different source (ex: humans) ○ Animals have digestive system to break down food ○ Mammals-different teeth shapes to eat certain foods ○ Birds- different beak shapes to eat certain foods Life Functions ○ Growth/Development/Rep roduction: Some plants grow from seeds like plants with flowers (angiosperms) and cones (gymnosperms). ○ Some plants grow from spores like moss and ferns. ○ Spores do not have to be fertilized. ○ Seed plants use pollen and ovules (eggs) during sexual reproduction. Pollen-male structure and ovule- female structure. ○ Methods of pollination- insects, birds, mammals, wind, etc. Life Functions ○ Growth/Development/Reproduction: ○ Insects/amphibians go through metamorphosis (adult and young do not compete for food) ○ Reproductive methods: ○ Animals in the water (fish/amphibians) use external fertilization; large # of eggs fertilized at 1 time ○ Mammals utilize internal fertilization ○ 3 types: ○ Monotremes – Egg layers (Platypus) ○ Marsupials – Partial development in pouch (Kangaroo) ○ Placental – Complete development in uterus Innate Behaviors ○ Behaviors an animal is born with ○ Includes: ○ Suckling (attachment for feeding) ○ Migration (leave north to go south for warmer climate) ○ Hibernation (during winter months) ○ Estivation (dormancy during hot period) ○ Phototaxis (movement toward/away from light) ○ Chemotaxis (movement toward/away from chemical stimulus) ○ Ex: weaving of spider webs; Social Behaviors ○ Communication between individuals of the same species ○ Courtship (ex: male peacock as he spreads his tail feathers to attract a mate) ○ Territorial (ex: Male Betta fish) ○ Chemical/pheromones to communicate things such as the location of food (ex: bees, ants, termites) Learned Behaviors ○ Habituation-learned by repetition or “habit” and there is a decrease in response to stimulus (ex: prairie dogs) ○ Imprinting-animal forms a social attachment to another animal at an early, critical time in their life (ex: baby duck will follow the first animal that it sees upon hatching) ○ Classical conditioning-animal associates one type of behavior with a reward (ex: Pavlov’s dog) ○ Trial and error-trying various responses until one is rewarded Human Population/Exponential Growth ○ Growth: Birth rate-Death rate ○ Current human population has little to no limiting factors ○ Larger the population, the faster it grows (Growth speeds up over time) ○ Unlimited resources (food, shelter, mates, land, etc.) ○ “J” shaped ○ As human population increases, resources such as fossil fuels are consumed at an increasing rate Carrying Capacity/Logistic Growth ○ “S” shaped ○ Maximum number of individuals that an ecosystem can support-carrying capacity ○ Limiting factors (cause population to decrease): ○ Food availability ○ Competition ○ Disease ○ Predation ○ Natural Disasters ○ Climate ○ Territory (space) Effects of Disease on Ecosystems ○ Ecosystems with lots of variation (genetic diversity and diversity of species) are more resilient to the impacts of diseases because: ○ Greater possibility that some species have evolved resistance ○ If a species is lost there will be another species to fill the niche of an extinct species Human Impacts ○ Positive ○ Negative ○ Reforestation ○ Acid Rain ○ Cover Rotation (plant ○ Deforestation (increase CO2 different crops each year to & decrease O2) replenish nutrients/decrease ○ Habitat Destruction mineral loss in soil) ○ Invasive Species ○ Recycling-preserve natural ○ Ozone depletion from the resources release of CFCs ○ Sustainable practice (Reduce, ○ Remove trees-increase reuse, and recycle) erosion-leads to water runoff and decrease of habitats North Carolina Ecosystems Impacts ○ Acid rain effects in mountains (rain=acidic and killing trees in mountains) ○ Beach erosion (rise in global sea levels due to global warming and melting of glaciers ○ Urban development in the Piedmont leading to habitat destruction &water runoff ○ Kudzu as an invasive plant (overtakes and kills native species) Invasive Species ○ Plants, animals, or other organisms that are are introduced to a given area outside their original range and cause harm in their new home; ○ No natural enemies or predators ○ Outcompete local species and rapidly expand in population Global Warming ○ Increase in the average temperature of the earth ○ Caused by the release of too much CO2 into the atmosphere which amplifies the greenhouse effect ○ Major cause: Burning of fossil fuels, volcanic eruptions Bioaccumulation ○ An increase in environmental toxins that occurs as you move up a food chain ○ Organisms higher on the food chain eat more and the more an organism eats the more toxins that they ingest ○ Ex. DDT and birds of prey Topic 3 Questions 1. How does carbon enter plants? 2. List two ways that consumers return carbon to the atmosphere? 3. What process is explained by carbon dioxide holding heat in the atmosphere? 4. Why is nitrogen important to humans? 5. What happens to energy as it moves up the food chain? Why? 6. What two structures do most plants use for transport of materials? What is the difference between the two? 7. What are the structures within plants’ leaves that allow gas exchange and excretion of wastes? 8. What process is described by loss of water from a plants leaves? 9. In addition to gas exchange, what is the overall goal of respiration? 10. How do plants obtain nutrients? 11. What is the advantage of a spore? 12. What is the advantage of external fertilization? 13. Contrast monotremes, marsupials, and placental mammals. 14. How are estivation and hibernation similar? How are they different? 15. What social behavior is displayed by Betta fish? 16. Give an example of each of the following: a. communication using pheromones b. courtship behavior c. phototaxis 17. After moving to his new home, a man is startled several times per day due to close proximity to a passing train. According to habituation, what should eventually happen? 18. Why might imprinting be necessary for survival of an animal? 19. Which behavior is described by associating a certain behavior with a reward, such as with Pavlov’s dog? 20. Contrast mutualism and parasitism. 21. What happens to a prey population if the predator population decreases? Why? 22. What are limiting factors? Give two examples. 23. What happens when a population reaches carrying capacity? 24. What two things have increased along with increasing human population. 25. How has acid rain affected the mountains of NC? 26. Why are hog farms damaging to NC ecosystems? 27. Why is Kudzu so bad? 28. Why do pesticides kill animals such as eagles? 29. What can you do to have good Stewardship (help preserve the environment for the future)? Topic 4: Evolution and Genetics ○ Bio 3.1 Structure and Function of DNA ○ Bio 3.1.1 DNA-double stranded ○ Bio 3.1.2 DNA and RNA code for proteins and determine traits ○ Bio 3.1.3 Mutations ○ Bio 3.2 Expression of Genetic Traits ○ Bio 3.2.1 Meiosis/Sexual Reproduction/Genetic Variation ○ Bio 3.2.2 Inheritance Patterns ○ Bio 3.2.3 Environmental Factors ○ Bio 3.3 DNA Technology ○ Bio 3.3.1 DNA Comparison and Identification ○ Bio 3.3.2 Transgenic Organisms ○ Bio 3.3.3 Ethical Issues ○ Bio 3.4 Theory of Evolution by Natural Selection ○ Bio 3.4.1 Evidence for Evolution ○ Bio 3.4.2 Natural Selection ○ Bio 3.4.3 Disease Agents ○ Bio 3.5 Classification Systems ○ Bio 3.5.1 Historical and Modern Systems ○ Bio 3.5.2 Evolutionary Relationships DNA/RNA ○ Monomer/Subunit/Basic Building Block: Nucleic Acids ○ Store genetic information ○ Made of a chain of nucleotides composed of: ○ Sugar ○ Phosphate ○ Nitrogen base DNA vs. RNA DNA RNA ○ Double stranded ○ Single stranded ○ Double Helix ○ “Twisted Ladder” ○ Four base pairs: (backbone: sugar and AUCG phosphate) ○ Sugar is Ribose ○ Four base pairs: AGCT ○ “Rungs of ladder” (inside: complementary base pairs Adenine to Thymine and Cytosine to Guanine) ○ Sugar is Deoxyribose ○ Found in nucleus ○ The sequence of DNA determines which proteins are made. Proteins are important for building things within the body and in chemical reactions (enzymes). Base Pair Rules ○ In DNA: ○ Adenine always pairs with Thymine ○ Guanine always pairs with Cytosine ○ In RNA: ○ Adenine pairs with Uracil (NO THYMINE IN RNA) ○ Guanine pairs with Cytosine DNA Replication ○ Creation of an identical strand of DNA ○ Occurs during “S” phase (synthesis) of cell cycle ○ Daughter cells have an exact copy of parental DNA ○ “Semiconservative” model ○ 1 “old” strand (original) and 1 “new” strand “Central Dogma” of Biology ○ Protein Synthesis: DNA contains the code for RNA, which codes for protein ○ DNA → RNA → Protein Transcription ○ Creation of an RNA copy of a DNA segment ○ DNA → mRNA ○ mRNA travels from the nucleus to ribosomes ○ Occurs in nucleus ○ Complementary mRNA strand is produced from a segment of DNA ○ 3 RNA types: ○ mRNA:(messenger)-carries blueprint ○ tRNA: (transfer)- gathers amino acids ○ rRNA: (ribosomal)- structural component of ribosomes Translation ○ Creation of proteins based on instructions carried by mRNA ○ Ribosome reads the message and helps assemble protein ○ tRNA bring amino acids to the ribosome according to the mRNA codons ○ Amino acids are linked together by rRNA using peptide bonds Codon ○ Sequence of three mRNA nucleotides that code for an amino acid Mutations ○ Change in sequence of nucleotides in DNA ○ Addition/Deletion: base added or deleted; each codon is shifted and the entire amino acid sequence/protein is altered and will most likely be nonfunctional ○ Substitutions: base or codon switched with another; alter 1 amino acid and will result in slightly altered amino acid ex: Sickle Cell ○ NOT always harmful ○ Caused by- Randomness/spontaneous or Radiation and/or chemical exposure (environmental influence) ○ Mutations in sex cells (egg or sperm) can be inherited Sickle Cell: recessive genetic disorder Resistant to malaria Sickle Cell Mutation Mitosis ○ Somatic (Body) Cell division ○ Produces two identical diploid (2n) daughter cells ○ Used in growth and repairing damage ○ Asexual reproduction ○ Examples: Cloning, binary fission, budding ○ Creates 2 identical diploid (2n) daughter cells ○ No genetic variation Cancer ○ Error in cell growth with causes uncontrolled cell growth ○ Cells never enter G0 phase, in which they normally stop dividing ○ Can be caused by a variety of environmental and genetic variables Meiosis ○ Sexual Cell division ○ Produces four different haploid (n) daughter cells (gametes) ○ Occurs in sex cells (gametes) egg or sperm ○ Sexual reproduction ○ 4 genetically different haploid (n) cells ○ Genetic variation/diversity ○ Independent assortment ○ Fertilization: egg + sperm ○ 2 rounds of cell division Crossing Over ○ Occurs during Prophase I of Meiosis ○ Homologous chromosomes exchange parts of their DNA ○ Creates variation in gametes Nondisjunction ○ Homologous chromosomes fail to separate during meiosis ○ Can lead to genetic diseases ○ Down Syndrome (Trisomy 21) caused by an extra chromosome on 21st pair Asexual vs. Sexual Reproduction Asexual Reproduction Sexual Reproduction ○ One parent ○ Two parents ○ Identical offspring ○ Offspring different ○ Variation only thru from parents mutations ○ More variation ○ Examples: budding, ○ Fertilization (fusion of fragmentation, gametes: n + n = 2n); fission, cloning zygote (2n) Law of Segregation ○ Alleles are randomly allocated to gametes during Meiosis Law of Independent Assortment ○ Genes are inherited independently of one another ○ Inheriting one allele for one gene does not influence the allele received for a different gene Inheritance ○ Traits are specific characteristics inherited from parents ○ Genes are the factors that determine traits ○ The different forms of a gene are called alleles Dominant/Recessive Alleles ○ Dominant alleles are expressed, if present, and recessive are hidden ○ Dominant alleles mask recessive alleles ○ Capital letters used for dominant alleles: ○ HH (homozygous dominant) or Hh (heterozygous dominant) ○ Lowercase letters used for recessive alleles ○ hh (homozygous recessive)  Genotype ○ The alleles an individual has for a trait ○ Homozygous (Homo- same) ○ Both alleles are the same ○ BB or bb ○ Heterozygous (Hetero – different) ○ Both alleles are different ○ Bb Genotypic Ratio: 1BB:2Bb:1bb Phenotype ○ The physical characteristic displayed by the individual (Ex. Brown eyes, hemophiliac) ○ Phenotype → Physical Phenotypic Ratio: 3 purple:1 white Incomplete Dominance ○ Heterozygous individuals show a blending of dominant and recessive traits ○ Ex. Red (RR), White (WW) ○ RW → Pink Codominance ○ Heterozygous individuals express both traits equally (Co – Together) ○ Ex: Roan (Spotted) Cows ○ RR – Red Cow ○ WW – White Cow ○ RW – Red/white spotted Polygenic Traits ○ Traits that are controlled by more than one gene ○ Many possible phenotypes ○ Traits are on a spectrum ○ Hair color ○ Eye color ○ Height Multiple Alleles ○ Certain genes may have more than two alleles for a trait (Still only inherit 2) ○ Ex: Blood type has 3 possible alleles ○ A, B, O ○ A and B are dominant, O is recessive ○ Type A: AA or AO genotypes ○ Type B: BB or BO genotypes ○ Type AB: AB genotype only (Codominance) ○ Type O: OO genotype only (Recessive) Sex-Linked Traits ○ Sex Chromosomes (23rd pair) ○ Female = XX ○ Male = XY ○ Sex linked traits are carried on the X chromosome only ○ More common in males (only have 1 X to inherit recessive allele) ○ Females would have to inherit 2 recessive alleles on X’s ○ Ex. Hemophilia, colorblindness ○ Recessive allele (affected) Pedigrees Male=square Female=circle Shaded=affected Strike Through=death If 2 parents (heterozygous dominant) have a trait, but their son or daughter does not, the trait is dominant and the unaffected offspring will be recessive. If 2 parents do not have a trait, but their son or daughter does, ○ Similar to a family tree the trait is recessive. The parents ○ Shows how a trait or must be heterozygous dominant disease is passed in a family and affected offspring will be recessive. Karyotype ○ Chart of someone's chromosomes (23 pairs) ○ From largest to smallest ○ Can determine chromosomal disorders and gender Down Syndrome Karyotype: Shows extra chromosome at 21st pair  Environmental Influences on Genes Genetic Condition Prevention Lung Cancer No smoking Skin Cancer Limited sun exposure, vitamin D, folic acid Type 2 Diabetes Diet low in sugar and regular exercise PKU Testing at birth; diet free of phenylalanine (dairy products) Heart disease Diet low in fat and regular exercise Malaria Sickle Cell Anemia (resistant) Human Genome Project ○ Sequencing of human DNA ○ 13 year project to map the human genome ○ Being used to develop gene therapies ○ Determine whether individuals carry genes for genetic conditions ○ Ex: SCID and Cystic Fibrosis Gel Electrophoresis ○ Technique used to separate molecules (DNA or proteins) based on size ○ Use restriction enzymes to cut DNA into fragments ○ Smaller fragments travel quicker and farther in the gel than do larger fragments and will be found at the bottom of the ○ “DNA fingerprinting” ○ Can be used to identify individuals, identify and catalogue endangered species Recombinant DNA ○ Cell with DNA from another source ○ Example: Bacteria used to produce human insulin ○ Step 1: Gene for human insulin isolated from human DNA ○ Step 2: Gene is cut and inserted into the bacterial chromosome (plasmid) ○ Step 3: Bacteria must then take in the plasmid so that it can use the insulin gene to make the insulin protein Bacterial Transformation ○ Insertion of a gene into bacterial plasmid ○ Can be used to make bacteria that produce certain chemicals ○ Ex: Bacteria with the gene for human insulin Transgenic Organism ○ An organism which contains DNA fragments from other organisms ○ Agricultural examples: Crops given genes for pest resistance ○ Medical examples: Human insulin producing bacteria ○ Glowing animals given genes for bioluminesence Origin of Life ○ Early Earth atmosphere was very hot ○ NO OXYGEN ○ First cells were anaerobic prokaryotes, then photosynthetic organisms evolved (Oxygenated atmosphere), followed by eukaryotic cells, and finally multicellular life Anaerobic prokaryotes > Photosynthetic prokaryotes > Eukaryotes > Multicellular Endosymbiotic Theory ○ Eukaryotic cells evolved from prokaryotes ○ Early prokaryotes engulfed other prokaryotes and developed symbiotic relationships ○ Evidence: mitochondria and chloroplast have DNA separate from the nucleus and have double membranes Abiogenesis Biogenesis ○ Living organisms ○ Living organisms may arise from come from other non-living sources organisms ○ Spontaneous generation ○ Disproved by Francesco Redi and Louis Pasteur’s experiments Natural Selection ○ “Survival of the Fittest” ○ Fitness: The ability to survive and reproduce in an organism’s environment ○ Put forth by Charles Darwin ○ Requires: ○ Genetic variation ○ Competition Peppered Moth Example 19th century Industrialization & coal fires led to air pollution Killed lichens and blackened tree trunks White moths were more 20th century obvious to predators reduce air pollution Black moths were tree trunks became cleaner camouflaged and safe from predators and more White colored moth was likely to reproduce and produce favorable camouflaged and offspring the dark colored moth was more noticeable. 5 Tenets of Natural Selection ○ Populations have variations ○ Sexual reproduction, mutations, etc. ○ Variations are inherited ○ Genes passed from parents to offspring ○ Organisms produce more offspring than can survive ○ Individuals with variations best suited for their habitat survive and reproduce ○ Beneficial genes are passed down ○ A population will change over time Adaptations ○ Beneficial trait that increases survival ○ Example: ○ Beaks that make it easier to eat insects ○ Bright flowers to attract pollinators ○ Vascular tissue in plants to adapt to life on land Evidence for Evolution ○ Homologous Structures ○ Same structures with different functions ○ Suggests a common ancestor that had the structure ○ Analogous Structures ○ Same function, different structures ○ No common ancestors Evidence for Evolution ○ Vestigial Structures ○ Structures that once had a function, but no longer do ○ Ex: ○ Human appendix ○ Whale hipbones Evidence for Evolution ○ Fossil Record ○ Older fossils can be compared to more recent ones to show how species evolved ○ Oldest fossils-bottom layers of rock ○ Newest fossils- top layers of rock ○ Fossils are contained in sedimentary rocks Biochemical Similarities (DNA) ○ DNA provides the best evidence because it can tell us exactly how closely related some organisms are ○ If DNA sequences of two organisms are similar, it suggests they are closely related Speciation ○ Emergence of a new species ○ Members of the same species (breed and produce fertile offspring) are separated by physical feature such as a river, volcanic eruption, or earthquake may evolve separately in different environments and lead to a new species Antibiotic and Pesticide Resistance ○ Populations will eventually become resistant to pesticides and antibiotics with overuse ○ The most resistant individuals survive and reproduce, creating a new, more resistant strain Coevolution ○ Two organisms evolve in response to each other ○ Ex: Flowering plants and pollinators ○ Flowers evolve long tubes suited to the long beak of hummingbirds Classification ○ Kingdom: Broadest (commonly used) category ○ Species: most specific category (must be able to interbreed and produce fertile offspring) ○ King Phillip Came Over From Great Spain ○ Kingdom – Phylum – Class – Order – Family – Genus – Species Domains ○ Three domains exist one level higher than the Kingdoms ○ Eubacteria – Common bacteria ○ Archaea – Prokaryotic cells, many are extremophiles ○ Eukarya – All eukaryotes (Animals, plants, fungi, and protists) Binomial Nomenclature ○ Two word naming system ○ Scientific name ○ Uses Genus and species names ○ Genus capitalized, species lower case ○ Both are italicized ○ Ex. Dogs: Canis familiaris Dichotomous Keys ○ Multi-step tool used to identify organisms ○ Paired set of questions with two choices Cladograms ○ Shows evolutionary relationships based on derived traits ○ Traits present in organisms evolved after a certain point Phylogenetic Tree ○ Shows the evolutionary relationships of several species branching from a common ancestor ○ The closer the species are to each other on the tree, the more closely related they are ○ Common ancestor – bottom of the tree Viruses ○ Not considered living things ○ Cannot reproduce independently ○ Pathogens that can mutate to resist vaccines ○ Ex. HIV, Influenza, Smallpox Immune Response ○ B Cells ○ Fight antigens in body fluids ○ Create antibodies ○ Make memory cells after exposure to antigens ○ T Cells ○ Fight pathogens inside living cells ○ May help B-cells make antibodies ○ Make memory cells after exposure to pathogens Immunity Passive Immunity Active Immunity ○ Antibodies are ○ Antibodies are introduced into the acquired when an body from another immune response is organism activated in the ○ Short-term immunity body ○ Ex; Mother transfers ○ Long-term immunity antibodies to infants ○ Vaccines trigger this through by introducing the breastfeeding body to a weakened form of a pathogen Parasites ○ Lives on or within a host ○ Benefits while causing harm to the host ○ Ex. Plasmodium causes malaria (genetic influence- carriers of sickle cell are resistant to malaria) Topic 4 Questions 1. What makes up the sides of the DNA ladder? 2. What is found in between the bases of DNA? 3. What does the sequence of DNA determine? 4. What is transcription and where does it occur? 5. What is being translated into amino acids? 6. Which nucleic acid brings amino acids to the ribosomes? 7. Describe the two types of proteins. 8. What type of cells are created through meiosis? How is the number of chromosomes in these cells different from the original cell? 9. What are two ways do the new cells of mitosis compare to the new cells of meiosis? 10. What are the ways that meiosis creates variation in offspring? 11. What is the difference between heterozygous and homozygous? 12. Which of these would be a genotype? GG or green? 13. What is the difference between codominance and incomplete dominance? How are they alike? 14. Why are males more likely than females to inherit sex-linked traits? 15. What two things can be found from a karyotype? Which chromosomes represent the 23rd pair? 16. If two parents have a trait and their son or daughter do not, what is the genotype of the parents? Is this a dominant or recessive trait? 17. How can PKU be prevented? 18. Having the condition of sickle cell anemia may prevent you from contracting which other condition? 19. What are restriction enzymes used for? 20. Which fragments travel farther in gel electrophoresis? 21. Give one medical uses of transgenic bacteria. 22. What are some evidences of evolution? 23. What is geographic isolation?