1. Describe two pieces of evidence suggesting that species change through time.
2. Describe the evidence Darwin brought forward in support of his theory of common ancestry,
3. Outline Natural Selection as threee premises, three conclusions, and a corollary.
4. What evidence did Darwin use to support the contention that the environment acts as a selective "breeder"? Think of what might happen to different organisms in the same environment, and similar organisms in differnt environments.
5. What were Darwin's three dilemmas, and what solution did he propose for each?
6. Distinguish between the 'ovist', 'homunculan', and 'blending' ideas about heredity.
7. Explain how reciprocal crosses test the Ovist and Homunculan hypotheses? How did the results suggest that both parents must contribute?
8. List Mendel's first three postulates, clearly and specifically stating his 'first principle' of heredity without using the word 'segregate' in your definition.
9. Why is a test cross an effective way of determining the GENOTYPE of an organism expressing the dominat phenotype?
10. Determine the genotypic and phenotypic ratios from the following crosses. Assume dominance of capital letter:
a. AA x AA
b. AA x Aa
c. Aa x Aa
d. Aa x aa
e. aa x aa
11. Why did Mendel conduct an F1 x F1 cross (the second generation of crosses)? What hypothesis did this test?
12. What question was Mendel addressing with his dihybrid cross?
13. How did the results lead him to hypothesize that the traits must be inherited independently? Use the product rule in your answer.
14. State Mendel's second principle, without using the word 'independent' in your definition.
15. Consider this cross: (male) AaBbCcDD x (female) AaBBccDD
- Assume independent assortment and dominance (capital is dominant to lower case) at each gene.
- How many types of gametes can each parent make with respect to these traits?
- How many genotypes and phenotypes are possible in the progeny?
- What fraction of offspring would you expect to express the ABCD phenotype?