Lecture Final Study Guide

This study guide has now been updated for Fall 2019.

The final will be Wednesday, December 11, 2019, 11:30-1:30 in the lecture room. Note the time! One hour earlier than our usual lecture time.

The format will be similar to the midterms, with one free-response and 50 multiple-choice questions. The long answer will count for one third of the points.

Free-response questions

There will be one free-response question on the final, chosen from a list of five. I will add more questions to this list as the final approaches.

1. Compare and contrast diving in humans (both free diving and SCUBA) and in marine mammals. Include the gas-related problems that can arise due to diving, and how marine mammals avoid these problems. What makes marine mammals better divers than humans?
2. Compare and contrast the ways that cows and rabbits extract energy from diets consisting largely of cellulose; relate this to the structure of each animal’s digestive tract. If a human received the gut microbiome of a cow, could he live on a diet of grass? (Hint: first you must explain why cellulose is a problem.)
3. Describe how hormonal systems and the kidney interact in humans to maintain homeostasis with respect to blood volume, pressure, and osmolarity.
4. Diagram and describe how countercurrent exchange mechanisms work. Use specific examples for: (1) gas exchange; (2) thermoregulation; (3) osmoregulation; and (4) reducing evaporative water loss from breathing. (One example for each.)
5. Compare and contrast a dolphin and a tuna in terms of gas exchange, thermoregulation, and osmoregulation. (Hint: these are not three separate topics. The mechanisms of gas exchange, thermoregulation, and osmoregulation are interdependent. In this question, I’m asking you to integrate topics that came up at different points in the quarter. Key idea: air vs. water. Assume that the dolphin and the tuna are approximately equal in mass, live in the same ocean environment, and eat the same food.)

 Review multiple-choice questions

There will be 50 multiple-choice questions. More than half of those questions will be review, covering material that was on the midterms; these questions will be very similar to the questions that were on the midterms. Use your midterms as a study guide for these.

The rest will be new material from the last sections of the course, as outlined below.

Important concepts for new multiple-choice questions

Sensory systems

• Types of sensory receptors. What’s wrong with the traditional 5-senses idea?
• Sensory transduction in sensory receptor cells
• Second messenger
• Gated ion channel: Na⁺ flow into cell starts action potential
• Resting potential & action potential; What are the spikes on the little graphs?
• Signaling within a cell vs. signaling between cells.
• Evolution of chemoreceptor proteins & chemoreceptor organs. Which came first, and how do we know?
• Mammals have many different odor receptor proteins. Do they all occur in the same cell?
• Stretch receptors
• Mechanoreceptors: Lateral line sense and hair cells. Why is the lateral line found in fish but not humans or dolphins?
• Statocysts: Who has them, and what do they do?
• Semicircular canals of various vertebrates: Compare to statocysts.
  
• Human ear, structure & function: cochlea & hair cells. How do we perceive loudness? How do we perceive pitch?
• Snake ears
• Insect hearing: compare to mammal.
• Echolocation in bats & dolphins. Why does it work so much better for dolphins? What are the advantages & disadvantages of hearing underwater vs. in air? Why does sound work as a weapon for dolphins, but not for bats?
• Electroreceptors (modified hair cells). Why don’t mammals have them?
• Weak electric fish & strong electric fish.
• Heat receptors: pit organs. Why are they in pits? Why don’t aquatic animals have them? Why are they only found in a reptile that preys on mammals?
• Eyes: flatworms & other simple eyes. Why does it matter if the eye is cup-shaped? What does screening pigment do? Why don’t flatworms have fancier eyes?
• Compound eyes: advantages & disadvantages; ommatidia
• Color vision: dichromatic & trichromatic
• Opsins & retinal as photoreceptor proteins. Is vision analogous to chemoreception, homologous, or neither?
• Rods & cones.
• Eye focusing
• How light signals reach the brain. How do you know what color you’re seeing?
• Squid eyes & vertebrate eyes. What parts are homologous; what parts are analogous? How does studying the developmental process help us understand the evolutionary process?
• What does Pax-6 do?

Reproduction

• Reproduction compared to sex. What is sexual reproduction? Roles of meiosis and syngamy.
• Asexual reproduction is clonal growth.
• Hermaphrodites: sequential & simultaneous. Why do sexual reproduction at all if you’re a hermaphrodite? Why don’t they usually fertilize themselves?
• Parthenogenesis
• External fertilization, including free spawning. What sorts of animals free spawn? What disadvantages does free spawning have, and how are some species adapted to it?
• Internal fertilization. How are species with internal fertilization different from those with external fertilization?
• Cleidoic eggs & amniotic eggs. Which of these features are found in mammals? How is nitrogenous waste handling connected to cleidoic eggs and extraembryonic membranes?
  
• Amniotic eggs & extraembryonic membranes of mammals
• The role of viruses in the evolution of placental mammals
• Hormonal regulation of the ovarian and uterine cycles
• Hormonal regulation of sperm production