III. True-False questions. (1 point each = 5 points):
1. Diffusion will occur, if a concentration gradient exists.
2. When a founder population has a small gene pool, evolutionary change is more likely to be rapid than if the founder population has a large gene pool.
3. Stabilizing selection is a pattern of natural selection that favors an average, not extreme, expression of a trait.
4. Once an adaptive feature appears, it remains in all the descendant unless the species becomes extinct.
5. Humans are more likely to be infected by viruses after the viruses had a chance to multiply outside the body on surfaces touched by infected people.
IV. Matching of Terms/Concepts with Definitions/Associations. Place the correct number on the line behind each term. (1/2 point each=5 points)
Term or Concept
Water molecule ___
Ionic Bonding ___
Covalent Bonding ___
1. energy source
2. two atoms sharing electrons
3. electron donated/received
5. element found in all living organisms
7. OH– > H+
9. characteristic of all living organisms
10. H+ > OH–
V. Brief essay questions: Please write a concise and succinct response to each one of the following questions; be sure to mark your answers with the correct essay number. I am looking for clarity and detail which reflects your knowledge of the subject. Always include appropriate examples, if warranted. (Total possible points=30)
1. The habitat of one species of tropical fish is red coral reefs. The large majority of the fish in this populations are red. A few individual fish carry a mutation that prevents the production of the red pigment; as a result, these fish are white. The temperature of the ocean where these fish live becomes warmer and warmer over a ten year period, and, as a result, the coral is bleached and turns white. Use what you have learned about natural selection to explain how this bleaching event may have affected the evolution of this fish population (not including possible direct effects of warmer temperatures for the fish). Include the following terms in your explanation: Differential reproduction, beneficial trait, allele frequency, selection pressure, evolution (5 possible points)
2. You scoop up a water sample from a local pond nearby, because you are curious about the possible microbes that might live there. After looking at several slides that held drops of the sample, you noticed two different kinds of cells: One kind was very small and had no separate internal structures; the other kind was much larger, and it contained several kinds of internal structures that were physically different from each other. Please name each cell and briefly describe their overall similarities and differences. (5 possible points)
3. Humans share 99% of their genes with chimpanzees, 90% with mice, 50% with fruit flies, and 37% with celery. Please explain the evolutionary significance of these data. Phylogenetic details here are essential. (5 possible points)
4. A population of pygmy-deer becomes re-established on an island after having been absent for a very long time. They are given ‘protective status’, and flourish in numbers. Then an unusually long and harsh winter happens. The deer are seen eating bark, raiding bird feeders, and some die. Describe both the density-dependent and density independent factors at work here, and explain what might be happening to this population. Terms such as carrying capacity, and birth and death rates must be part of your discussion. (5 possible points)
5. When a rabbit eats the lettuce in your garden, all of the energy in the lettuce is used by the rabbit. Is this statement true or false? Defend your answer. Your answer must be detailed about energy conversions and trophic levels. (5 possible points)
6. Before recombinant products were available, humans who needed hormones or other biological products, such as insulin, had to use products that were harvested from other humans and non-human animals. Can you think of specific health risks that might be associated with products that were not made with genetically engineered bacteria? (5 possible points)