Question

1.In fruit flies, eye color is an X-linked trait. Red eyes (X^R) are dominant over white eyes (X^r)A homozygous dominant female mates with a white-eyed male. What is the phenotypic ratio among males?

a.1:0 (all male offspring will have red eyes)

b.1:1 (half of the male offspring will have red eyes and half will have white eyes)

c.0:1 (all male offspring will have white eyes)

2.In fruit flies, eye color is an X-linked trait. Red eyes (X^R) are dominant over white eyes (X^r).

A homozygous dominant female mates with a white-eyed male. What is the phenotypic ratio among females?

A. 1:0 (all female offspring will have red eyes)

B.1:1 (half of the female offspring will have red eyes and half will have white eyes)

C.0:1 (all female offspring will have white eyes)

3.In sheep, horns are sex linked; H = horns and h = no horns. What cross do you recommend if a farmer wants to produce hornless males?

A.Cross 1:   X^HY x  X^HX^H

B.Cross 2:   X^hY x  X^HX^h

C.Cross 3:   X^HY x  X^hX^h

D.Cross 4:   X^HY x  X^HXh

4.

A = adenine

T = thymine

C = cytosine

G = guanine

U = uracil

A DNA strand is used as a template to make an RNA strand. Write out the complementary RNA bases for the following DNA sequence: A C G G T T             

5. Name the process that makes an mRNA strand from a DNA template strand.

6.Name the process that requires tRNA, mRNA, and a ribosome.

7.In pea plants the purple flower allele (P) is dominant to the white flower allele (p).

If there is a population of 10 pea plants homozygous for purple flowers, 20 heterozygous, and 10 pea plants with white; what is the frequency of the P allele in the population.

A.0.25

B.0.33  

C.0.05

D.0.75  

E.0.50

8.In pea plants the purple flower allele (P) is dominant to the white flower allele (p).

If all of the pea plants with white flowers are eaten, what is the new frequency of the p allele?

A.0.33

B.0.25

C.0.75  

D.0.5

9.True or False. Natural selection CAUSES mutations.

A.True

B.False

10.Is a population bottleneck an example of genetic drift?

A.no

B.yes

Answer 1

Ans:

1. a.1:0 (all male offspring will have red eyes)

Explanation: If a homozygous dominant female (X^RX^R) mates with a white-eyed male (X^rX^r), the phenotypic ratio of males is 1: 0 (all male offspring have red eyes).

All other options are incorrect because all the resulting male offsprings are red eyed.

2. A. 1:0 (all female offspring will have red eyes)

Explanation: If a homozygous dominant female (X^RX^R) mates with a white-eyed male (X^rX^r), the phenotypic ratio of males is 1: 0 (all female offspring have red eyes).

All other options are incorrect because all the resulting female offsprings are red eyed.

3. C.Cross 3:   X^HY x  X^hX^h

Explaination: if a farmer wants to produce hornless males, I recommend cross 3 because this cross only produces hornless males. The cross 1 produces all horned males while cross 2 and 4 produces 50% horned and 50% hornless males.

4. The complementary RNA bases for the DNA sequence A C G G T T is U G C C A A because in complementary sequence the bases are opposite to DNA strand sequence and T is replaced by U in RNA.

5. Transcription is the process that makes an mRNA strand from a DNA template strand by the help of enzyme RNA polymerase.

6. Translation is the process that requires tRNA, mRNA, and a ribosome for synthesis of protein.

7. The frequency of P allele is 0.50

Explanation:

All other options are incorrect because the calculated frequency of P allele is 0.50