Question

1. __________ can cause genes to move from one linkage group to another

A. Inversions

B. Deletions

C. UV-light exposure

D. Translocations

E. Unequal crossing over

2. Transposons that use RNA as an intermediate differ from DNA-only transposons in that the activity of former requires?

A. Indirect repeat at one end and direct repeat at the other

B. A gene for transposase

C. A gene for reverse transcriptase

D. A gene for RNA polymerase

E. A selectable marker such as kanamycin resistance

3. Given that sequencing projects find patients with similar types of cancer have cancerous cells with thousands of unique mutations, we can infer that:

A. all these mutations are necessary to induce a cancerous state.

B. cancer involves a breakdown in DNA repair processes.

C. there are many tumor suppressor genes protecting cells.

D. mutation is a random process and many changes are unconnected to cancer.

E. the unique DNA mutations must arise during gametogenesis.

4. A polygenic trait that exhibits only two phenotypic categories is said to be a ________ trait.

A. Continuous                                       D. Threshold

B. Meristic                                               E. Correlated

C. Semidiscontinuous

5. In a cross between aaBbCcDdEe and AaBbccDdee, what proportion of the offspring would be expected to be A_bbC_DDE_? (A_ means AA or Aa.)

A) 3/256   

B) 1/64

C)3/64

D) 1/128

E) 3/128

6. What is the most obvious phenotype of tapeworms that infect tapeworm-resistant threespine stickleback fish?

A) parasites exhibit less movement/contractility

B) worms are extremely small

C) parasites turn a blackish color

D) tapeworms die immediately after entering the fish

E) worms develop a harder tegument to protect themselves from the fish immune response

7. Which of the following statements describes the “wobble” rules CORRECTLY?

A) There is a flexible pairing between tRNA and amino acid as there are more tRNAs

than the number of amino acids.

B) The number of codons in the genetic code exceeds the number of amino acids

available in the cell.

C) The third base pairing between the tRNA and mRNA is relaxed.

D) There are multiple codons that may code for the same amino acids.

E) There are multiple tRNAs that may bind to the same amino acids.

8. Base substitutions that occur in non-coding regions like introns are most likely to be

A. Conditional mutations

B. Transversions

C. Missense mutations

D. Nonsense mutations

E. Silent mutations

Answer 1

1. "Translocations" can cause genes to move from one linkage group to another. Translocation results in the rearrangement of chromosomal genes between two non-homologous chromosomes. Deletions and inversions can cause rearrangement of genes on the same chromosome. Crossing over causes exchange of genes between two homologous chromosomes. UV light exposure causes mutation in genes.

2. The correct answer is "C. A gene for reverse transcriptase" ​​​. Retrotransposons require reverse transcriptase because RNA intermediate is converted to DNA before insertion into the target sequence.