Question

Circle the correct answer.

1) An organism with IsCAP+P+O+Z+Y+A+/F’I+ will have a normal functioning Lac operon.

a) True

b) False

2) Different genotypes can have different selection coefficients.

a) True

b) False

3) Given the mRNA sequence: 5’AUCAAAGUUCA 3’ Which of the answers below represents the corresponding coding DNA sequence?

a) 3’ ATCAAAGTTCA 5’

b) 5’ TAGTTTCAAGT 3’

c) 5’ ATCAAAGTTCA 3’

d) 3’ TAGTTTCAAGT 5’

4) Consider a gene with three alleles controlling coloration of a flowering plant. There are 3 possible phenotypes, corresponding to the following dominance hierarchy among the alleles: A1 is dominant to A2 and A3, and A2 is dominant to A3. Which of the following genotype pairs express the same phenotype?

a) A1A2, A1A3

b) A2A3, A1A3

c) A2A2, A3A3

d) A1A1, A3A3

5) Cells that go through the rDNA process are then placed on a selective antibiotic media that also contains X-gal. Colonies of cells that appear white on the media have the recombinant form of the plasmid.

a) True

b) False

6) After sequencing a molecule of DNA, you discover that 30% of the bases are cytosine (C). What percentage of the bases would you expect to be thymine (T)?

a) 15%

b) 40%

c) 30%

d) 20%

7) One red flowered plant and one white flowered plant breed and produce offspring. All of their offspring have pink flowers. Which of the following is true?

a) This is an example of codominance

b) This is an example of dominant suppression

c) This is an example of recessive epistasis

d) This is an example of incomplete dominance

8) Cross together two heterozygous parents for plant height and flower color (genotypes: SsWw for both parents; S=tall, s=short, W=purple/violet, w=white). What is the probability that a randomly selected offspring will be tall and have white flowers?

a) 9/16

b) 3/16

c) 4/16

d) 1/16

9) Deoxyribose nucleoside triphosphate (dNTP) mix is an essential component in PCR. What does the dNTP mixture contain?

a) Magnesium chloride and Taq polymerase

b) Adenine, uracil, guanine, and cytosine

c) Adenine, thymine, guanine, and cytosine

d) Magnesium chloride, ATP, and nucleotides

Answer 1

1. False

I^s is a dominant negative repressor. It binds to the operator even in the presence of lactose.

2. True.

Different genotypes respond differently to the selection pressure. So, they exhibit different selection coefficients.

3. Option C is correct.

Coding sequence = 5'-ATCAAAGTTCA-3'

mRNA sequence = 5’-AUCAAAGUUCA-3’

See image

4. Option A is correct.

A1>A2>A3

If A 1 is present, it is expressed irrespective of other alleles.

5. True

True recombinants contain the disrupted b-gal gene. So, they appear white on X-gal plate.

6. Option D is correct

A = T

G = C

If C = 30%, then G = 30%

G+C = 60%

A+T = 40%

A = T = 20%

7. Option D is correct.

8. Option B is correct.

9. Option C is correct.