II. Environmental Interactions:

1) Provide an example of conditional expression of coat color at different termperatures, explaining WHY the color vaires at differnt temperatures.

2) What is PKU, what causes it, and how can it's effects be interrupted?

3) How can the location of a gene influence its expression? describe an example.

4) Describe the pattern of imprinting for IGF-2 and the competititve receptor. Describe Haig's hypothesis for the adaptive value of this pattern of imprinting for males and females.

5) What is a CpG island, where are they common, and how are they invovled in imprinting?

6) Explain how either Prader-Willi or Angelman's Syndrome are caused.

7) "Maternal Effects" can be caused my maternal proteins placed in the egg that influence the phenotype of the developing embryo. Explain why, in Limnaea snails, an organisms coiling is not depedent on its own genotype. Provide an example (draw a family tree that demonstrates your argument).

8) Another type of maternal effect can be caused by mitochondria or chloroplasts. Why? And why can these effects vary over the organism?

9) The "value" of an allele is often independent of its phenotypic effect. So, an allele might have a given effect on the phenotype, but whether this effect is beneficial or deleterious depends on.... what? describe how the allele that causes malaria is an example of this.