Physiological Ecology, Bio 31 First Midterm exam 23 April 2015 Name: KEY

Transcription

1 Physiological Ecology, Bio 31 First Midterm exam 23 April 2015 Name: KEY 5 pts 1. Identify the bird species: Hairy Woodpecker 12 pts 2. Briefly define each of the following terms. sacrificial protein - IRGA - apomorphy - Frankia - Medawar zone - thermal sum - proteins that are apparently produced by some herbivores to bind with dietary tannins; usually composed of easily obtained amino acids (e.g., proline); produced in salivary glands of some ruminants and peritrophic membranes of some insects Infra-red gas analyzer; used for measuring the CO2 concentration in a gas sample (as in measurements of respiration or photosynthesis). A derived/unique character within a clade; i.e., a newly evolved feature (not possessed by ancestral species) Nitrogen-fixing bacterial symbiont found in root nodules of actinorhizal plants, e.g., Alnus in Betulaceae research questions of moderate difficulty (not too easy and not too hard) where the expected returns of research efforts tend to be maximized (named after P. Medawar, the philosopher of science who described the pattern) The sum of temperatures per hour or day accumulated above a developmental threshold. A frequent predictor of the phenology of biological events. 10 pts 3. Draw two functions in each of the graphs below representing a 20 g roadunner (a bird, beep-beep ) and a 20 g lizard living in the same high desert environment. Label the lines roadunner and lizard. 3 pts 4. All organisms, in all lifestages, have biochemical pathways that allow the controlled release of energy from organic molecules. Why? Life depends upon nonrandom associations of molecules; i.e., life is the antithesis of entropy. Therefore, sustenance of life requires a constant input of energy to counter entropy and maintain homeostasis. Metabolism is the controlled release of biochemically manageable energy units (ATP) that can be expended to maintain homeostasis. Additionally, allows organisms to cope with changing environments by storing energy and regulating release in times of stress. 6 pts 5. Give three possible adaptive reasons for why many ruminants tend to include a diversity of plants in their diet. 1. Maintain diversity of gut flora 2. Acquire a balanced diet (one that contains all essential nutrients) 3. Keep all secondary metabolites at sublethal doses 4. Ease potential food limitations page 1

2 6 pts 6. Spruce budworm (Lepidoptera: Tortricidae) is an important forest pest in Canada and northern New England. The overwintering eggs hatch at budbreak and larvae feed during early summer on expanding needles of fir and spruce. Young needles permit rapid larval growth; mature needles are of poor quality for larvae. Spruce budworm occurs in the Hanover area but has never been known to reach outbreak levels this far south. This pattern could be explained by the phenological race hypothesis (PRH). In the figures below, depict predictions of the PRH if it could explain the geographic pattern. The graphs represent a cool Canadian summer (left) and a warmer New Hampshire summer (right). In each graph:! sketch a function representing caterpillar development (using dashed line)! sketch a function representing needle development (using solid line)! indicate on the X-axis the point at which needle maturation is complete 5 pts 7. On a global scale, where are the terrestrial ecosystems with the highest primary productivity? Why? Equatorial Regions/Tropics 1. Higher incidence of solar radiation/energy input 2. Increased rainfall/moisture 3. Increased temperature 4 pts 8. Why are hoatzins so odd? A very rare case of a leaf-eating bird. The adaptations for herbivory include: enlarged crop modified for ruminant-like gut fermentation of cellulose; almost flightless; large size and correspondingly low mass-specific metabolic rate; conservative investments in reproduction (usually two eggs per clutch). The adaptations required for feeding on leaves (e.g., low metabolism) runs counter to fundamental features of birds, which is presumably why herbivorous birds are rare. 3 pts 9. Name two species of mammals (from different families) that occur in the Second College Grant during winter. About 24 species representing 11 families. See 4 pts 10. Give two adaptations (as noted by Heinrich) of Golden-crowned Kinglets for surviving winter. 1. Voracious consumption of small overwintering larvae that are hidden on tree branches 2. Continuous foraging each day from first light to last light 3. Bulky insulating feathers 4. Overnight group huddling page 2

3 6 pts 11. Compare the metabolic rate of the following pairs of animals. For each pair, circle the animal with a higher mass-specific metabolic rate (kj kg -1 d -1 ), and underline the animal that must assimilate more total energy per day (kj animal -1 d -1 ). 5 g shrew vs 3800 kg elephant 0.2 kg lizard vs 1 kg jackrabbit 500 g frog vs 50 g frog 6 pts 12. Nina grows chickens. Each summer she buys 8 10-kg bags of chicken feed from which she raises g chickens. She is considering raising another batch during the winter. She has estimated that the average daily metabolic of her free range chickens will be twice as high in the winter as in the summer. How many chickens could she expect to produce from the same amount of chicken feed in the winter? Winter chickens per 80 kg chicken feed: 12 chickens The chicken feed is cracked corn, which the feedstore says is 30% assimilable energy. The chicken breed is Plymouth Rock, thought to be derived from a species native to Asia. Show your work. Use back of page as needed. Identify notable assumptions. Total assimilation = 24 kg (80 kg feed 0.30 assimilation efficiency. Total production = 8 kg (20 chickens 0.4 kg / chicken) Therefore total respiration = 16 kg (24-8). Assumes negligable energy lost via excretion. Therefore, respiration per chicken in summer = 0. 8 kg respired / chicken (16 kg / 20 chickens) Chicken respiration in winter becomes 1.6 kg / chicken (2 0.8 kg). Then cost of producing one chicken in winter = 1.6 kg respiration kg production = 2.0 kg. Then 24 kg assimilable energy yields 12 chickens in winter. 4 pts 13. Congratulations. You have become part of the food chain and have acquired an intestinal parasite. The clinic could not identify the parasite, but have ascertained that it is operating in an anaerobic region of your gut. They were also able to sequence the genome. How could you use the genomic data to determine if your parasite was primitively anaerobic vs. the anaerobic metabolism being a derived condition in your parasite. If the parasite is secondarily anaerobic, its genome would be expected to contain recognizable sequences of DNA that formerly coded for the expression of all the particular enzymes and proteins that are associated with the Krebs cycle and elecfron transport chain. 6 pts 14. What are the essential postulates of the theory of evolution by common descent (not to be confused with the theory of evolution by natural selection)? Life on earth has originated only once New species are derived by splitting from existing species (through reproductive isolation with subsequent modification) Extinction is forever Therefore, all species are related to all other species but in varying degrees and cladograms can provide valid graphical models of the evolutionary history and relatedness among taxa. page 3

4 10 pts 15. Assume that:! A black-throated blue-warbler weighs 20 g.! There are 10 pairs of warblers per 10 ha.! Basal metabolic rate falls on the interspecies curve for birds (V0 2 = 0.85 M 0.75, where V0 2 = liters O 2 h -1 and M = mass in kg).! Oxidative metabolism releases kj / liter O 2.! The birds eat caterpillars that are feeding on leaves in the forest understory! There are 30 mg of caterpillars per 1000 leaves.! The energetic content of caterpillars is 20 kj / g.! There is an average of 80 understory leaves / m 2.! One hectare (ha) = 100 x 100 meters. About what percentage of the caterpillar biomass could the warblers consume in one day. Show your work (use back of facing page as needed). State any important additional assumptions that may be required. % caterpillar biomass consumed in one d a y = approximately 23% page 4

5 10 pts 16. Populations of Papilio canadensis in Alaska frequently feed on balsam poplar (which is common in Alaska) and never on black cherry (which does not occur in Alaska). Populations of P. canadensis in Michigan frequently feed on black cherry (which is common in MI) and rarely feed on balsam poplar (which is rare in MI). Briefly describe an experiment that would test for regional adaptation of P. canadensis populations for improved growth performance on locally available host species. In the empty figure, sketch one set of possible results and interpret them in the space at lower left. Be sure that the figure is adequately labelled. Brief summary of experiment Reciprocal transplant experiment in which both the growth of caterpillars from both Alaska and Michigan was measured on both balsam poplar and black cherry. Possible results Interpretation of results shown at right The results at right indicate adaptation of both AK and MI populations to the host plants that are more typical in their region. page 5

6 Number students Bio 31: Spring 2015, 1st exam Mean = 69 SD = 5 2 Pages graded 1-2 Andy 3-4 Matt 1 Approximate grades >88 A A B B B C Number students Bio 31: 1st exam, historical Mean = 76 SD =