Sample questions for Biol 7 first exam.
For multiple choice questions there may be more than 1 correct answer, select all that are accurate answers to the question.

1. The tail of mice can be either normal (N) or bent (B). The following crosses were done and show the phenotypes of the parents and the offspring.

Cross	Parents		Offspring
	Female	Male	Female	Male
1	N	B	All B	All N
2	B	N	1/2 B, 1/2 N	1/2 B, 1/2 N
3	B	N	All B	All B
4	N	N	All N	All N
5	B	B	All B	All B
6	B	B	All B	1/2 B, 1/2 N

A. Is the allele for a bent tail a dominant or recessive trait?

B. Is the gene for tail morphology autosomal or sex-linked?

C. What are the genotypes of all the parents and their progeny?

2. Draw the thymine and adenine bases, showing the base pairing between the two.

3. Which of the following statements are accurate about the Avery, MacLeod, and McCarty experiments?
A. DNA purified from S colonies of Streptococcus had the ability to transform R colonies.
B. Treating the cell extracts with ribonucleases (RNases) did not destroy the transforming factor activity.
C. Their work relied on the radioactive isotopes ³²P and ³⁵S.
D. A major conclusion of their studies was that one gene encodes one protein (polypeptide).

4. Which of the following is NOT required by DNA polymerase for the synthesis of a new strand of DNA?
A. A DNA template.
B. ATP.
C. The 4 deoxynucleoside triphosphates.
D. A primer that provides a 3'-OH.

5. The A,B,O blood groups in humans show which of the following types of characteristics?
A. Multiple genes affecting a phenotype.
B. Multiple alleles for 1 gene.
C. Incomplete dominance for some of the alleles.
D. Epistasis.

6. If DNA replication were conservative, what would you expect the banding pattern of DNA to be in CsCl gradients in the Meselson-Stahl experiment?