University of Otago Zoology Exam BIOL112 2023 PDF

UNIVERSITY OF OTAGO EXAMINATIONS 2023 ZOOLOGY BIOL112 Animal Biology Semester 2 (TIME ALLOWED: TWO HOURS) This e...

UNIVERSITY OF OTAGO EXAMINATIONS 2023 ZOOLOGY BIOL112 Animal Biology Semester 2 (TIME ALLOWED: TWO HOURS) This examination paper comprises 22 pages Candidates should answer questions as follows: Section A: Diversity and Evolution (26 marks) Section B: Form and Function (32 marks) Section C: Animal Interactions (22 marks) The following material is provided: Nil Use of calculators: No calculators are permitted Candidates are permitted copies of: Nil Other Instructions: (a) Write your STUDENT ID NUMBER in the space provided at the top of ALL pages. (b) FINAL answers must be entered in the spaces provided: there is no separate answer sheet. (c) All multiple-choice questions are to be answered by circling one correct answer. There is no separate multiple-choice answer sheet. (d) Hand in the entire exam attached to green attendance receipt. TURN OVER Student ID _______________________ BIOL112 SECTION A: Diversity and Evolution (26 marks) Allow about 39 minutes Animal Diversity (13 marks) 1. You come across an animal. It is a radially symmetrical acoelomate with a gastrovascular cavity. (a) How many embryonic tissue layers does this animal have? (1 mark) ____________________________________________________________________ (b) To which phylum does this animal belong? (1 mark) ____________________________________________________________________ 2. Rank the following phyla (Arthropoda, Chordata, Mollusca, Porifera) in order of least number of known species to greatest number of known species. (2 marks) __________________________________________________________________________ 3. Fill in the blanks using the correct words: (2 marks) The deuterostome developmental mode is characterised by ___________________ and ___________________ _cleavage and the development of the ________________ from the blastopore. An example of a phylum which undergoes deuterostome development is _______________________. 2 TURN OVER Student ID _______________________ BIOL112 Animal Diversity (continued) 4. Eight animals (A-H) are depicted in Figure 1 below. A B C D E F G H Figure 1 (a) How many phyla are represented in Figure 1? (1 mark) ____________________________________________________________________ Use only the letters A-H to answer the following questions- do not write animal names. (b) Which animal(s) belong to the clade Ecdysozoa? (1 mark) ____________________________________________________________________ (c) Which animal(s) are amniotes? (1 mark) ____________________________________________________________________ (d) Which animal(s) have an open circulatory system? (1 mark) ____________________________________________________________________ 3 TURN OVER Student ID _______________________ BIOL112 Animal Diversity (continued) 5. Controlling invasive species is New Zealand’s primary conservation method. List THREE other methods discussed in class that are key to conservation. (3 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 4 TURN OVER Student ID _______________________ BIOL112 Animal Evolution (13 marks) 6. Mass extinctions reduce diversity by killing off specific lineages, and with them, any descendent species they might have given rise to, but mass extinctions can also play a creative role in evolution. Explain how mass extinctions can stimulate the emergence of new species. (3 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ __________________________________________________________________________ 7. Supporters of the Biological Species Concept see reproductive isolation not only as the key to defining a species, but also in explaining how species diversify. List THREE mechanisms by which species could become reproductively isolated, and briefly explain why these isolating mechanisms can lead to new species being formed. (3 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 5 TURN OVER Student ID _______________________ BIOL112 Animal Evolution (continued) 8. In Australia, evolution has resulted in a diversity of marsupial mammals that resemble eutherian mammals in other parts of the world. For example, the Australian sugar glider and the North American flying squirrel look very similar with their big eyes, white belly and thin membrane that connects their forelimbs to their hindlimbs that they use to glide through the air (see Figure 2 below). However, sugar gliders are more closely related to kangaroos and koalas (see Figure 2 below). Using this example, explain the concepts of convergent and divergent evolution. (3 marks) Figure 2 ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ 6 TURN OVER Student ID _______________________ BIOL112 Animal Evolution (continued) 9. Male deer (bucks) in some populations are reaching sexual maturity with smaller antlers than they did in the past. Some biologists suggest that this change is related to hunting because bucks with larger antlers are most prized and therefore taken by hunters more often than bucks with smaller antlers. Use natural selection theory to explain the decrease in antler size. (3 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 10. With reference to question 9, explain why this statement, “The bucks know that if they grow big antlers, they will be hunted before they can reproduce, so they grow their antlers slowly and reproduce as quickly as they can” is a misconception of natural selection theory. (1 mark) __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ END OF SECTION A 7 TURN OVER Student ID _______________________ BIOL112 SECTION B: Form and Function (32 marks) Allow about 48 minutes Animal Physiology (11 marks) The bee hummingbird is the world’s smallest bird, weighing only 2.6 grams. The common ostrich is the world’s largest living bird, with adult birds weighing between 90-130 kilograms. Figure 3: Bee hummingbird and common ostrich. 11. When comparing the bee hummingbird to the common ostrich, which of the two: (a) would have the higher basal metabolic rate? (0.5 mark) __________________________________________________________________________ (b) would have the higher standardised basal metabolic rate per gram of body mass? (0.5 mark) __________________________________________________________________________ 12. Bee hummingbirds lose body heat much more quickly than an ostrich. Explain why this is the case. (1 mark) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ 8 TURN OVER Student ID _______________________ BIOL112 Animal Physiology (continued) 13. Hummingbirds are endotherms. Some species of hummingbirds undergo daily torpor at night to conserve energy. Using Figure 4 below, explain why hummingbirds are endothermic poikilotherms. (2 marks) Figure 4: Hummingbird body temperature (°C) and environment temperature (°C) over a four-day period. 0600 refers to 6 AM (approximate time of sunrise). Dashed line is internal body temperature, solid line shows ambient environmental temperature. ____________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ 14. The diet of hummingbirds consists mainly of nectar, supplemented with insects. Which of the four modes of feeding would hummingbirds be employing when obtaining nectar? (1 mark) (a) Bulk feeding (b) Filter feeding (c) Fluid feeding (d) Substrate feeding 9 TURN OVER Student ID _______________________ BIOL112 Animal Physiology (continued) 15. Hummingbirds, like all animals, need to acquire essential nutrients from their diet. List the FOUR classes of essential nutrients. (2 marks) ____________________________________________________________________ ____________________________________________________________________ 16. The respiratory system of birds is often compared favourably to the respiratory system of mammals as many consider the bird system to be more efficient at extracting oxygen. List TWO reasons that support the statement that birds have a more efficient respiratory system than mammals. (2 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 17. Fish use single circulation to distribute blood around their body whereas birds use double circulation. Describe ONE advantage and ONE disadvantage of double circulation compared to single circulation. (2 marks) Advantage: ____________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ Disadvantage: ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 10 TURN OVER Student ID _______________________ BIOL112 Nervous Systems (11 marks) 18. Which of the following is the correct sequence of processes (1-6) during signal propagation in neurons? (1 mark) Processes: 1. Synaptic input from presynaptic neurons 2. Depolarisation of the axon hillock membrane 3. Release of neurotransmitter into the synaptic cleft 4. Integration of synaptic potentials 5. Propagation of action potentials along an axon 6. Fusion of vesicles with presynaptic membrane (a) 1, 6, 5, 3, 4, 2. (b) 1, 3, 4, 2, 5, 6. (c) 1, 4, 2, 5, 6, 3. (d) 1, 2, 4, 6, 5, 3. 19. Two compartments (A and B) are shown in Figure 5 below. They only contain water, Cl-, Na+ and K+ ions. Ion concentrations in A and B are indicated. A and B are separated by an impermeable membrane. Ions are able to move through channels in the membrane. The membrane has more Na+ channels than K+ channels i.e., the membrane has a lower resistance for Na+ ions than for K+ ions. Initially, all channels are closed. Figure 5 Which of the following describes what happens to the membrane potential when all channels open at once? (1 mark) (a) The membrane on the B-side becomes negatively charged as compared to the membrane on the A-side. (b) The membrane on the A-side becomes negatively charged as compared to the membrane on the B-side. (c) There is no change in membrane potential. (d) An action potential will be generated. 11 TURN OVER Student ID _______________________ BIOL112 Nervous Systems (continued) 20. “Nervous systems encode information in action potentials”. Explain this statement and include in your answer the function of sensory neurons, inter neurons and efferent neurons. (3 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 21. List TWO types of animal behaviours that are generated by a type of neural circuit that is called a “central pattern generator”. (1 mark) __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ 22. Explain the process of sensory transduction. (2 marks) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ 12 TURN OVER Student ID _______________________ BIOL112 Nervous Systems (continued) 23. The cupula is a jelly-like sheath which encapsulates the sensory hairs of the hair cells. What is ONE function of the cupula? (1 mark) __________________________________________________________________________ __________________________________________________________________________ 24. The identity of an odour is encoded by the combination of activated receptor neurons. This process is called “combinatorial coding”. What is the advantage of “combinatorial coding” as compared to “labelled-line coding”? (2 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 13 TURN OVER Student ID _______________________ BIOL112 Hormones and Reproduction (10 marks) 25. Signalling through chemical messengers can take different forms. (2 marks) Match the following five terms with the appropriate picture in Figure 6 that best represents each term. Write the letter (A-E) corresponding with each term in the space provided under each picture. Each letter (A-E) can only be used once. A: endocrine signalling B: autocrine signalling C: neurotransmission D: paracrine signalling E: neuroendocrine signalling ________ ________ ________ _______ _______ Figure 6 26. Chemical communication requires a signal, and a system to receive and respond to the signal: the receptor. Receptors come in different shapes and sizes while their location (intracellular or in the membrane) is dependent on the (bio)chemical property of the ligand. Explain the differences in how intracellular receptors and membrane receptors work. (2 marks) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ 14 TURN OVER Student ID _______________________ BIOL112 Hormones and Reproduction (continued) 27. Tamoxifen is a chemical that may be used to treat breast cancer. It is an estrogen receptor antagonist. Explain what an antagonist is, and why a physician might prescribe tamoxifen to treat breast cancer. (2 marks) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 28. A major product of the reproductive axis of male vertebrates is testosterone. List TWO functions of testosterone in male vertebrate animals. (2 marks) __________________________________________________________________________ ____________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ 29. Sex reversal (‘sex change’) in fishes is not uncommon. Applying your knowledge of hormones and reproduction, how would the levels of sex steroid hormones change when a fish undergoes sex change from the female to the male phenotype? (2 marks) __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ END OF SECTION B 15 TURN OVER Student ID _______________________ BIOL112 SECTION C: Animal Interactions (22 marks) Allow about 33 minutes Animal Behaviour (11 marks) 30. In summer on Whenua Hou (Codfish Island), male kākāpō gather in leks. Here they produce low-frequency booming sounds and metallic chinking calls from saucer- shaped depressions (called bowls) which they excavate in the ground. Suggest a ‘proximate’ reason and an ‘ultimate’ reason for this behaviour. (2 marks) Proximate reason: ____________________________________________________________________ __________________________________________________________________________ ____________________________________________________________________ Ultimate reason: ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 31. List TWO benefits and TWO costs of living in a social group. (2 marks) Benefits: ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ Costs: __________________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 16 TURN OVER Student ID _______________________ BIOL112 Animal Behaviour (continued) 32. In Brazil, the masses of butterflies which congregate on riverbanks are frequently hunted by birds. Some butterflies “mud-puddle” in large groups, while others suck up fluids from the mud by themselves or in small groups. What relationship do you expect to see between group size and the probability of capture by birds? (1 mark) ____________________________________________________________________ ____________________________________________________________________ Name the strategy butterflies in large groups are using. (0.5 mark) ____________________________________________________________________ 33. Archey’s frog is a New Zealand frog species in which the male protects the eggs and carries the young on its back during the first few months of life. If you investigated the mating system of this species, bearing in mind Triver’s Parental Investment Theory, what predictions could you make about parental investment in males compared to females, mate competition and mate selection in this species? (2 marks) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 34. Vervet monkeys live in dense forest and give an alarm call when a predator is detected. (a) Is this an example of a VISUAL, CHEMICAL, or ACOUSTIC mode of communication? Circle ONE option. (0.5 mark) (b) What are TWO benefits of using this mode of communication to transmit this information? (2 marks) ___________________________________________________________________ ___________________________________________________________________ 17 TURN OVER Student ID _______________________ BIOL112 Animal Behaviour (continued) (c) In which of the following scenarios would alarm calling by vervet monkeys be considered altruistic? (1 mark) i. The caller had a low coefficient of relatedness with the rest of the group. ii. The benefit to the caller outweighed the cost. iii. The call benefited relatives. 18 TURN OVER Student ID _______________________ BIOL112 Animal Associations (11 marks) 35. On coral reefs, the relationship between cleaner fish and the many fish species serving as their ‘clients’ is considered to be mutualistic. List ONE benefit for both the cleaner and for the clients of taking part in this behavioural symbiosis? (2 marks) For the cleaner: _______________________________________________________ ____________________________________________________________________ For the clients: ________________________________________________________ ____________________________________________________________________ 36. Phoresy has often been considered to be a type of commensalism. Which of the following definitions best characterises a phoretic relationship? (1 mark) (a) Feeding on a much larger host with no impact on the host’s fitness. (b) Temporary attachment on a larger host to obtain transport to a new location. (c) Laying eggs on a much larger host with no impact on the host’s fitness. (d) Permanent attachment on a much larger host as a living habitat. 37. When comparing parasitic copepods with their closest free-living relatives, what structures or organs are typically absent in parasites, presumably lost over the course of evolution? (1 mark) (a) Sensory organs, gonads, and segmentation. (b) Appendages, sensory organs, and exoskeleton. (c) Appendages, gut, and sensory organs. (d) Exoskeleton, segmentation, and gonads. (e) Appendages, exoskeleton, and gut. 38. Hookworms (nematodes of the genera Necator and Ancylostoma) infect millions of people in the tropics. They follow a complicated migration through the tissues of their host, before settling in the intestine. Which of the following is the correct order of tissues or organs traversed by hookworms during their migration? (1 mark) (a) Oesophagus, trachea, lungs, heart, skin, blood vessels, intestine. (b) Skin, blood vessels, lungs, trachea, heart, oesophagus, intestine. (c) Skin, blood vessels, heart, lungs, trachea, oesophagus, intestine. (d) Oesophagus, trachea, lungs, heart, blood vessels, intestine. 19 TURN OVER Student ID _______________________ BIOL112 Animal Associations (continued) 39. Figure 7 below summarises the life cycle of a parasite that played a major role in New Zealand sheep farming, the cestode Echinococcus granulosus, which causes hydatid disease in sheep. (2 marks) Figure 7 (a) What animal is the definitive host of Echinococcus granulosus? _________ (b) In which host does E. granulosus reproduce asexually? _________ (c) Does transmission via eggs occur at step A or B in Figure 7? _________ (d) What is a simple method of controlling E. granulosus? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 20 TURN OVER Student ID _______________________ BIOL112 Animal Associations (continued) 40. Figure 8 below summarises the life cycles of two parasites common in the intertidal areas of Otago Harbour, the trematode Curtuteria australis (three hosts = snail, clam, bird) and the acanthocephalan Profilicollis sp. (two hosts = crab, bird). Figure 8 Both parasites reach their bird host by predation, i.e., the bird must eat an infected prey for the life cycle to continue. What is a common strategy used by many parasites transmitted by predation to increase their chance of transmission? (1 mark) __________________________________________________________________________ __________________________________________________________________________ 41. If you investigate one particular species of parasitic worm in a natural population of animals, not every individual host will carry the same number of parasites. Some individuals will have more parasites than others: a certain percentage of the population will have few parasites, a certain percentage will have a little more, and so on. From the options (i-v) provided in Figure 9, what is the typical pattern almost always observed in natural populations? Write the correct option in the space provided below. (1 mark) Figure 9 Graph that shows typical pattern: ___________________ 21 TURN OVER Animal Associations (continued) 42. When studying natural populations of animals, we must often rely on indirect evidence to determine whether parasites cause mortality. For instance, animals often accumulate parasites over time, i.e., as they get larger. Let’s say you have a sample of many individuals from a fish population, and you count the number of worms of a particular species you find in each fish. If you plot the number of parasites as a function of fish size, you may be able to determine whether or not heavy parasite infections cause mortality. From the options (i-v) provided in Figure 10 below, choose the graph showing the lines/curves you would expect if parasites cause mortality, and if parasites have no effect on fish mortality. Write the correct option in the space provided below. (2 marks) Figure 10 Graph that shows expected pattern: ________________ END OF SECTION C 22 END