Evolutionary Biology Part Ii

EXAM II 2014 EVOLUTIONARY BIOLOGY – PART II

______Name ______TA Name ______Lab Day & Time

Negative Points Positive Points

______12 pts

______16 pts

______12 pts

______10 pts

TOTAL ______50 pts B. B. Fill in the blank with the best answer. Be as specific as possible. (1 pt each)

______1. What do we call genes that control a cluster of other genes during embryological development?

______2. Name a plant that lacks xylem or phloem.

______3. What do we call the relationship when two species interact, each one modifying the evolution of the other? E.g. myxoma virus and rabbits in Australia.

______4. What is the process called when a plastid is passed from one bacterium to another?

______5. What is the byproduct of photosynthesis in blue green bacteria?

______6. What kind of point mutation could lead to a frame-shift?

______7. If a skin cell of an animal usually has 10 chromosomes, how many chromosomes would its sperm cell have?

______8. Where is O2 used in the eukaryotic cell?

9-12 Using the following chart (where + indicates having a particular trait, and 0 indicates not having a particular trait), place labeled tick marks appropriately on the tree below.

Hair Placenta Binocular Vision Rumination

Frilled Lizard 0 0 0 0

Koala + 0 0 0

Gorilla + + + 0

Impala + + 0 +

Frilled Lizard Koala Impala Gorilla

2. C. Definition Questions. Define the following terms or phrase giving an example and answer the follow up question. Do not be superficial in your responses; give details (4 pts. each)

1) Horizontal gene transfer

What is the relevance of this phenomenon to evolution and scientists ability to determine phylogenies?

2) Genetic Drift

Under what circumstances can this be more important to evolution that natural selection?

3) Keystone species

Why does it seem critical that wildlife managers keep this concept in mind?

4) Lytic life cycle (Give the steps and explain clearly)

What is the critical difference between this cycle and the lysogenic cycle? 3.

D.. Short Answer Questions (3 pts each) State whether the statement is true or false and then give the evidence supporting your claim

1) In mammals, females are usually more selective in their mating preferences than males; this is consistent with the argument that they have a greater parental investment in their offspring.

2) Biologists have a hard time explaining the altruistic behavior of some animals since it apparently runs counter to an individuals’ genetic self-interest.

3) Resource partitioning and character displacement explain the fact that two species of birds look rather similar when they live in different areas, but they look quite different when they live together

4) Some features of organisms are so complex and intricate they are said to be Irreducibly Complex, meaning that the organ cannot function unless all of the pieces are in place (e.g. the blood clotting mechanism consisting of dozens of enzymes and products; if anyone is missing the blood fails to coagulate). This is an example of an Intelligent Designer and that all of the pieces were put into place simultaneously. 3

E. Long Question (10 pts) Some years ago scientists from Yale reported that some people have an ability to taste a chemical called propylthiouracil (PROP) and others can’t. A test was administered by having people put a piece of paper laced with PROP in their mouths for a few seconds. Some people taste a strong bitter flavor, other people taste a mild bitter flavor, and still others taste nothing at all. This appears to be a genetically determined trait that produces three types of tasters. Researchers think it depends upon the number of special taste buds on the tongue. Answer the following questions with explanations. (10 pts.)

a. Is this likely to be a polygene trait? Why?

b. Can we distinguish between complete dominance, incomplete dominance, and co-dominance in the expression of the trait? If so how can we do that?

c. If 100 people were tested and we found the data shown below, would this suggest that the population is in Hardy Weinberg equilibrium? Super tasters =16%, medium tasters =48%, and non-tasters =36% . Show your work.

d. If the above were true, would you expect either genetic drift or selection to play a strong role in determining the proportion of individuals with the various tasting abilities? e. Suppose that tasting is a dominant trait, if two medium tasters were to have children, what types and proportions of phenotypes would you expect?