BIO 224 Midterm Review L1-5 PDF

General Concepts: 1.​ What is an animal? 2.​ Animal Characteristics 3.​ Animal Diversity 4.​ Animal Origins 5.​ Animal Classification 1.​ Animal Origins 1.​ What is an animal? Common ancestor for all of kingdom animalia = c...

General Concepts: 1.​ What is an animal? 2.​ Animal Characteristics 3.​ Animal Diversity 4.​ Animal Origins 5.​ Animal Classification 1.​ Animal Origins 1.​ What is an animal? Common ancestor for all of kingdom animalia = colonial flagellated protist in Precambrian. Animal = non-human animals. How do we know this? All members of the ​ Similarity to the modern colonial flagellated species. animalia kingdom. ​ Morphological and molecular evidence support this. Animal vs Plant Cell 1.​ Animal Characteristics Animal = no cell wall. No CENTRAL vacuole, just vacuoles. ​ Multicellular eukaryote Cell wall = provides tissue stability (lacks cell wall) Plants = cell wall and central vacuole. ​ Heterotroph ​ Motile ​ Sexual or asexual reproductivity ​ Has nerves and Tissue Stability in Animals muscles Why is it different from plants? --> Because animal cells do 1.​ Animal Diversity not have a cell wall. What makes an animal 'diverse'? How is stability achieved in tissues by animals? ​ Extracellular junctions ​ Diverse species ​ Cell junctions ​ Diverse habitats These junctions maintain cell shape, structure, and function. ​ Diverse characteristics Types of Junctions: 1.​ Anchoring junction- attach proteins to join cells together. 2.​ Tight junction- prevents things from passing through cells. Holds cells very close together. 3.​ Gap junction- allows for cell-cell communication, as well as ion exchange. TERMS FROM THIS LECTURE: ​ Protostomes ​ Deuterostomes ​ Spiral cleavage ​ Radial cleavage ​ Blastopore ​ Gastrulation ​ Vegetal Pole ​ Diploblast ​ Triploblast ​ Endoderm ​ Mesoderm ​ Ectoderm ​ Tissues ​ Body Symmetry ​ Radial symmetry ​ Bilateral symmetry ​ Segmentation ​ Body Cavity ​ Acoelomate ​ Pseudocoelomate Main Concept: Classifying Animals Animal Body Plans Sexual Reproduction Animal Body Plans Influences on animal body plans: ​ Embryonic development pattern ​ Germ cell layers ​ Body symmetry ​ Body cavity type Sexual Reproduction ​ Most animals undergo some form of sexual reproduction. Process: ​ Germ line cells undergo meiosis --> haploid gametes are produced. ​ Gametes fuse (fertilization) --> diploid zygote is formed. Asexual Reproduction Examples: ​ Budding in hydra ​ Fragmentation in echinoderms ​ Parthenogenesis in insects PROTOSOMES ​ Exhibit spiral cleavage. ​ Each cells developmental path is determined as the cell is produced. ​ Each blastomere CANNOT become a complete organism by itself. ​ Determinant Cleavage: develops into function NOT organism. DEUTEROSTOMES ​ Exhibit radial cleavage. ​ Developmental path is undetermined. ​ Each cell can for a complete organism by itself, meaning cells can be removed. ​ Indeterminant cleavage: can develop into complete organism. Sexual Reproduction Process: Timeline- Fertilization --> Zygote --> Cleavage --> Morula --> Blastula ZYGOTE: Zygote cleavage is formed following fertilization. ZYGOTE CLEAVAGE --> division of cells in the early embryo. Undergoes rapid cell cycles with NO significant growth. Zygote then develops into a compact cell mass --> MORULA MORULA: Morula derives into a hollow sphere of single layer of cells --> BLASTULA Gastrulation: Follows cleavage. Blastula --> Gastrulation --> Gastrula Begins at the vegetal pole. Blastula invaginates. Undergoes differentiation into 2 or 3 germ layers. GERM LAYERS: ​ Ectoderm (outer) ​ Mesoderm (middle) ​ Endoderm (inside) Why is there different germ layers? Germ layers differentiate to form tissues and organs. Definitions: Tissues- groups of similar differentiated cells specialized for particular functions. DIGESTIVE SYSTEM POLARITY: Blastopore always develops first. But the ends (poles) of the blastopore differ between Protostomes and Deuterostomes. Protostomes: mouth is developed first (vegetal pole), anus forms later. Deuterostomes: anus is developed first (vegetal pole), mouth forms later. Vegetal pole is the bottom of the blastopore and gastrulation ALWAYS begins here. PROTOSTOMES vs DEUTEROSTOMES Mesoderm Origin: P: Mesoderm differentiates near the blastopore. (bottom) D: Mesoderm originates from outpocketings. (top) GERM LAYERS Diploblastic animals (2) = animals that have 2 germ layers. Ecto- and Endo- derm. Triploblastic animals (3) = animals that have 3 germ layers. Ecto-, Endo-, and Meso- derm. ENDOderm: ​ Innermost layer ​ Forms gut lining; digestive tract MESOderm: ​ Between other layers (middle) ​ Forms body wall muscles and structures between gut and external covering; muscles and skeleton ECTOderm: ​ Outermost layer ​ Forms external covering (skin) and nervous system. EMBRYONIC DEVELOPMENT DIFFERENCES Protostomes Deuterostomes Cleavage pattern Spiral Radial Cell fate Determinant Indeterminant Digestive tract polarity Mouth from blastopore Anus from blastopore Mesoderm origin Differentiates near blastopore Originates from outpocketings Coelom origin Schizocoelom Entercoelom BODY CAVITY What is a body cavity? ​ A body cavity separates the gut from the body wall. ​ AKA coelom Deuterostome body cavity: Fluid-filled cavity between the intestines and the body wall. Protostome body cavities: Acoelomate- no body cavity, influences material diffusion Pseudocoelomate- false body cavity. Fluid filled or organ filled space between endoderm and mesoderm. BODY SYMMETRY Radial Symmetry: can be divided equally by any longitudinal plane. (diploblastic) Bilateral Symmetry: can be divided along a vertical plane at the middle. (triploblastic) Segmentation: Repeated structures along the anterior-posterior axis. Why? Movement and specialization. UNIFYING CONCEPTS Physiological processes must: ​ Obey the laws of physics and chemistry ​ Be tightly regulated usually. (homeostasis)  Terms from this Main Concept: Homeostasis Lecture: What is Homeostasis? ​ Negative Why is it necessary? Feedback What are methods of homeostasis? ​ Positive What is thermoregulation? Feedback ​ Feedforwa rd ​ Endother m What is Homeostasis? ​ Ectotherm ​ Regulation of the body's internal environment at ​ Homeothe or near a stable level. rm ​ Homeostasis regulates a physiological variable ​ Heterothe within a narrow range around a set point. rm Why is it necessary? ​ To allow an organism to reach optimal Thermoregulation physiological performance. Endotherm VS Ectotherm Homeostatic Methods ​ Location of needed body heat ​ Negative feedback loops ​ Positive feedback loops Endotherm = heat from internal ​ Feedforward physiological sources ​ If environment decreases, 1.​ Negative Feedback metabolism increases to warm Variable rises above the set point. up. Mechanisms of - feedback return variable back to set ​ Physiological and behavioural point. responses to changes in skin Minimizes difference between current level and set and core temperature. point. ​ Use negative feedback loops to maintain balance between 1.​ Positive Feedback heat loss and gain. Moves variable away from the set point. Used to quickly increase/decrease a process. Ectotherm = heat from external Eventually shut off by negative feedback. environment ​ If environment decreases, 1.​ Feedforward body temp also decreases. Future needs are anticipated. ​ Most aquatic invertebrates Physiology is adjusted in advance. Often involves learning and complex behaviours.  ​ Some use behavioural responses to regulate body temp. Homeotherm VS Heterotherm ​ Constant VS variable body temp. Homeotherms = maintains body temp at a constant level Heterotherms = vary between self-regulating their body temp and allowing environment to affect it. KEY TERMS FROM THIS LECTURE: ​ Thermoregulation ​ Organismal performance ​ Hypothalamus ​ Thermal acclimatization ​ Torpor ​ Vasoconstriction ​ Vasodilation Main Concept: Thermoregulation ​ Thermoregulation in Ectotherms ​ Thermal Acclimatization ​ Thermoregulation in Endotherms ​ Torpor Thermoregulation ​ Maintaining body temperature at a level that provides optimal physiological performance. Allows every body cell to function at optimal level. Organismal Performance: The rate and efficiency of an animals biochemical, physiological, and whole-body processes. Ectotherms ​ Obtain heat energy primarily from the external environment. Endotherms ​ Obtain heat energy primarily from internal reactions Thermal Acclimatization What? ​ A structural or metabolic change in the limits of tolerable temperatures as the environment alternates between warm and cool seasons. Why? ​ Allows animal to attain good physiological performance. ​ Increase in specific enzymes that work better at different temps. ​ Could change phospholipid saturation and cholesterol. Temperature Regulation- Endotherms ​ Changes in skin temperature causes changes in core temperature and body's attempt to thermoregulate.  ​ Thermoreceptors detect change in temp. (Hypothalamus = 'body thermostat') Hypothalamus: maintains core homeostatic functions. Skin and Endothermy Skin = organ of heat transfer How? ​ Blood vessels of skin regulate heat loss by vasoconstriction or vasodilation. ​ Skin = water impermeable. ​ Fatty tissue layer under blood vessels in skin limit the amount of heat loss. PROCESS: (FALL IN TEMP) 1.​ Thermoreceptors signal a fall in core temp. 2.​ Hypothalamus triggers compensating responses. 3.​ Signals are sent through the autonomic nervous system to restore temp. 4.​ Constriction occurs and reduces the flow of blood to the skin's capillary network. PROCESS: (INCREASE IN TEMP) 1.​ Thermoreceptors detect a increase in core temp. 2.​ Hypothalamus sends signals through ANS. 3.​ Signals relax smooth muscles of arterioles. 4.​ Vasodilation occurs, increasing blood flow. Temperature Variations ​ Temp. set point in many birds and mammals vary in daily and seasonal patterns. ​ Cooler conditions = lower set point; TORPOR TORPOR: A state of physical or mental inactivity; lethargy. KEY TERMS FROM THIS LECTURE: ​ Cells ​ Tissues ​ Organs ​ Organ systems ​ Epithelial tissue ​ Connective tissue ​ Muscle tissue ​ Nervous tissue ​ Glands ​ Skeletal muscles ​ Cardiac muscles ​ Smooth muscles Friday, January 31, 2025 9:32 AM ○​ Afferent ○​ Efferent ○​ Interneurons ○​ Dendrites ○​ Axons ○​ Myelin ○​ Glial cells ○​ Schwann cells Main Concept: Animal Body Organization & Nervous System ​ Layers of Organization ​ Animal Organ Systems ​ Tissue Types ​ Neuron Types ​ Neuron Structure ​ Glial Cells Organization of the Animal Body 1.​ Cells; specialized/organized into tissues. 2.​ Tissues; group of cells with the same structure and function. Work as a unit to carry out activity. 3.​ Organs; assembly of tissues integrated into a structure. Carry out a specific function. 4.​ Organ system; Group of organs that carry out related steps in a major physiological process. Cell properties in tissue = determine structure and function of tissue. Tasks of Organ Systems: ​ Acquire nutrients ​ Synthesize molecules. ​ Sense and respond to environment ​ Protect the body ​ Reproduce. Tissue Types: 1.​ Epithelial 2.​ Connective 3.​ Muscle 4.​ Nervous Epithelial Tissue ​ Sheetlike layers of cells. ​ Cover body surface and internal organs. ​ Lines cavities and ducts within body. ​ 5 types of epithelial tissue. 1.​ Simple Squamous ​ Layer of flattened cells. ​ Function = diffusion 1.​ Stratified Squamous ​ Several layer of flattened cells. ​ Function = abrasion protection 1.​ Cuboidal ​ Layer of cubelike cells. ​ Function = secretion and absorption 1.​ Single columnar ​ Layer of tall slender cells with nuclei at base. ​ Function = secretion, absorption, protection 1.​ Simple pseudostratified ​ Single layer of columnar cells of differing heights. ​ Function = protection, mucus secretion and movement. Connective Tissue ​ Consists of cell networks and extracellular matrix ​ Supports other body tissues ​ Transmits mechanical forces ​ Acts as a filter ​ 6 types of connective tissue 1.​ Loose connective tissue ​ Support, elasticity, diffusion. 1.​ Cartilage ​ Support, flexibility, joint movement 1.​ Adipose tissue ​ Energy reserves, insulation, padding 1.​ Fibrous Connective Tissue ​ Strength, elasticity. 1.​ Bone ​ Movement, support, and protection (Also Blood; substance transport) ​ 11 MAJOR Organ Systems: ​ 1.​ Respiratory 2.​ Digestive 3.​ Reproductive 4.​ Excretory 5.​ Nervous 6.​ Endocrine 7.​ Muscular 8.​ Skeletal 9.​ Integumentary 10.​Circulatory 11.​Immune Nervous Tissue ​ Neurons communicate information between body parts. ​ Glial Cells Muscle Tissue ​ 3 types 1.​ Skeletal muscles ​ Long contractile cells; muscle fibers. ​ Move body parts and maintain posture 1.​ Cardiac muscle ​ Short contractile cells with a branched structure. ​ Forms the heart. 1.​ Smooth muscle ​ Spindle shaped contractile cells. ​ Forms layers surrounding body cavities and tubes. Glands Function; secretory structures derived from epithelia. 2 TYPES 1.​ Exocrine ​ Secretions expelled outside of the body (by a duct). 1.​ Endocrine ​ Ductless. Neuron types 1.​ Afferent (sensory) ​ Conduct info. from sensory receptors. 1.​ Interneurons ​ Integrate information from afferent into a response. 1.​ Efferent (motor) ​ Carry response signals to effectors --> carry out a response. A basic neuron circuit is made up of all three neuron types. Glial Cells ​ Astrocytes and Schwann cells ​ Support/provide nutrients to neurons. ​ Provide electrical insulation ​ Scavenge foreign matter/debris. Astrocytes; maintain ion balance in surrounding neurons Schwann cells; form insulating layers (myelin) around axons. Neuron Structure Dendrites = receive signals and integrate/transmit them toward 'spike initiation zone (SIZ)'. Axons = conduct signals away from SIZ to another neuron or effector. Nervous System ​ Functions result from the activities of neurons and glial cells. ​ Nerves provide a common pathway between different structures and CNS. ​ CNS = ganglia and brain. Functions of Nervous System: ​ Reception ​ Integration ​ Transmission ​ Response