302 exam 1 - NAME: _ LAB INSTRUCTOR:_ ECOL 302 First...

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NAME: _______________________________________________________ LAB INSTRUCTOR:____________________________________________ 1 Page score_______ ECOL 302 – First midterm examination – Fall 2006 Put your name at the top of each page NOW. All questions are worth 10 points each. ANSWER IN THE SPACE ALLOTTED OR LESS. Use graphs or equations in your answers wherever you want or need to. 1. We found that adaptation is the key to understanding the success of organisms in their particular environment. Please describe one adaptation of an organism to its environment that we discussed in class. Please include both a description of how the adaptation works, and what environmental condition or constraint it is an adaptation for in your answer. A list of possibilities: Enzyme activity shifts with salt concentrations in bacteria Rainbow trout – 2 forms of AChE enzymes at 2 temperature ranges Counter current exchange and shunt in bird legs for freezing temperatures Counter current exchange in fish for efficient gas exchange C4 Photosynthesis/CAM Photosynthesis for hot, dry conditions Kangaroo rat to conserve water – behaviors: nocturnal, burrow microclimate, coprophagy; physiological: impermeable skin, nasal cooling, dry feces, concentrated urine The ability to acclimate (fish and temperatures; photosynthetic rates and temperatures) 2. Tropical songbirds tend to have nests with fewer eggs than birds nesting at higher latitudes. David Lack, of Oxford University, first placed this observation in a life-history context. First, what do we mean by ‘life-history strategy”. Second, what were the key concepts elaborated by David Lack in this regard? Life history refers to the schedule of an individuals life – age at maturity, # of offspring, life span, etc. Lack recognized that life-history traits are shaped by natural selection. He also proposed that life history traits contribute to reproductive success and thus to evolutionary fitness. They vary in predictable ways with environmental factors and constraints. Finally, he hypothesized that clutch size was related to availability of resources (food, in this case) and that experimental increase of clutch size would result in poor reproductive success . 3. The Pacific swingtail is a colonial-nesting seabird found only on an isolated coral island in the central Pacific Ocean. The swingtail feeds exclusively on adults of a large species of flying fish that it scoops from just above the ocean's surface. The ocean immediately surrounding the island is unproductive and essentially devoid of fish. However, there are small areas of upwelling at several different distances from the island that provides a source of flying fish for the swingtail. Below is an optimal foraging model for the Pacific swingtails. (a) Please label the axes. (b) What is labeled at point a.
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302 exam 1 - NAME: _ LAB INSTRUCTOR:_ ECOL 302 First...

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