Bio 162 Final Objectives Questions and Answers(A+ Solution guide)

Agonist - Competitive inhibition, binds to active site and causes a signal response in receptive tissue. Antagonist (blocker) - Competitive inhibitor, binds to active site so signal molecules cannot bind but causes no response in receptive tissue, can bind and release eventually. Apply your understanding of channels and synapses to predict how various neurotoxins affect nervous function. - Neurotoxins block receptor proteins on the post-synaptic neuron. Example: tetrodotoxin form Fugu fish block ion channels Are endotherms most commonly homeotherms or poikilotherms? What physiological mechanisms do they use to achieve this? - Endotherms are most commonly homeotherms because they can easily regulate their internal body temperatures themselves via their metabolic activity. Articulate the importance of phenotypic plasticity. - Phenotypic plasticity is a variation in morphological/phenotypic features determined by different environmental conditions. The 2 plants may have the same genes, they just look different because of the environment they are living in. Be familiar with the classic experiments that established that phototropism results from the unequal distribution of a hormone (auxin) in the stem. Explain what insight is gained from each experiment described on pages 769-770. - Briefly characterize the phases of the shoot apical meristem - The shoot apical meristem produces nodes and leaf cells under vegetative normal conditions, but when exposed to the proper light conditions- (either long days or short days), floragen, which is encoded for by the FT gene, travels from the leaf to the shoot apical meristem and signals the meristem to begin to produce reproductive cells (flower cells). Briefly summarize the Wood Wide Web hypothesis and site evidence that supports the idea of the Wood Wide Web. - Many plants in an ecosystem are connected through a network of fungi that transfer nutrients to and from one another.Can you think of other changes that could cause water potential of a plant cell to change? - Changes in pressure or solute concentration. Cell mediated response: - Cytotoxic T Cells (CD4+ Cells) attach to antigen on infected cells inject apoptosis inducing proteins into the cell and cause the cell to apopt and are then engulfed by macrophages. Compare and contrast endothermy and ectothermy, homeothermy and poikilothermy. - Endotherms: require more food, generate all their own internal body heat. Ectotherms (cold-blooded): Rely on environment for heat. Homeotherms: Body temperature is stable Poikilotherms: Body temperature is variable. Compare and contrast reproduction in marsupial mammals and eutherian (placental) mammals. - Compare and contrast the causes, prevalence, and treatments of type I and type II diabetes mellitus. - Type-I Diabetes : autoimmune disease due to no production of insulin, so there is nothing to promote glucose uptake by cells. Type-II Diabetes; Due to obesity and diet, cells insensitive to insulin, so glucose uptake cannot occur. Compare and contrast the extent of phenotypic plasticity typically seen in animals and plants. - Plants have a much higher degree of phenotypic plasticity than animals do due to the fact that they cannot move throughout their environment Compare and contrast the mechanisms by which birth control pills, emergency contraception, and abortion pills work. - Birth Control - small doses of progesterone/estrogen constantly taken into the body that inhibit the bodies natural production of those hormones. This prevents ovulation from occurring.Plan B (progesterone agonist) - extremely high dose of progesterone to quickly act on inhibiting the bodies natural production of those hormones. This acts to quickly prevent ovulation if it has not yet occurred. Abortion Pill (progesterone antagonist) - terminates established pregnancy by blocking progesterone receptors so menstruation occurs even after fertilization and implantation. Compare and contrast the three different types of vertebrate muscle. - Smooth: Involuntary; tapered cells with single nucleus; line organs, blood vessels, glands; neurons are part of the autonomic nervous system. Cardiac: Involuntary, branched with a single nucleus, only in the heart, can function without nerves, part of the autonomic nervous system. Skeletal: Voluntary; long, straight, multi-nucleated (to make new proteins easily); part of somatic nervous system. Compare and contrast voltage-gated ion channels and ligand-gated ion channels. - Voltage-gated ion channels: activated by a charge surrounding them. Ligand-gated ion channels: activated by binding of ligand to receptor. Compare how marine (both cartilaginous and bony fishes) and freshwater fishes osmoregulate. - Marine: Activley transport NaCl OUT and drink H2O in. Freshwater: Activley transport NaCl IN Compare the anatomy of xylem and phloem. - -Xylem: vessel elements, traecheids, and fibers. Vessel elements and tracheids both transport water and both have pits, but vessel elements have perforations on the end of their cell walls for water to pass through, while tracheids have pits for water to pass through between cells.-Phloem: sieve tubes (transport sugars), companion cells (regulate sieve tube element and participate in sugar transport), and sieve plates (porous membrane between sieve tube elements that allow passage of sugars). Compare the costs of locomotion for the three major types (flying, swimming, running).* - SwimmingFlyingRunning. As mass increases (small SA/V ratio), the drag is less, therefore the cost is less for the same animal type of each locomotive technique. Compare the osmoregulatory challenges of living in the ocean, in freshwater, and on land. - - Sharks (osmoconformers) store urea in their bodies and pump NaCl out to keep the osmolarity of their bodies the same as ocean to reduce h20 loss. -Bony saltwater fish (osmoregulators) keep their internal osmolarity lower than the salt water by actively transporting NaCl out and drinking water. -Bony freshwater fish (osmoregulators) keep their osmolarity higher than that of the surrounding water so they have to actively pump NaCl in and send water out. Consider resistance genes (R genes) and a-virulence genes (avr genes). In what organism are these genes encoded? Which encode receptors, which encode ligands? - R-Genes are present in plants and they encode for receptors. AVR genes are present in the predator and they encode for ligands that bind to the R-Genes Consider water as it moves from soil to root to stem to leaf to air. How does the water potential (w) in these different regions compare? - Water potential is the highest in the soil and is the lowest in the air. Water moves from High to low potential. Water has a higher potential in the soil so it moves out into the roots then from the roots to the stem then to the leaves then the air