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1.) What gives rise to different variations of traits within a species? Differen

ID: 276247 • Letter: 1

Question

1.) What gives rise to different variations of traits within a species?

Different alleles of a gene

Varying distances between genes

Natural selection

D. None of the above

2.) Crossing true breeding dark-coated sheep with true breeding light-coated sheep always results in 100% dark-coated offspring. You are screening a population of 300 Soay sheep for coat color, and you count 224 dark sheep and 76 light sheep. What is the genotype frequency of the homozygous recessive sheep for TYRP1 gene if the population is in Hardy-Weinberg equilibrium?

0.747

0.253

0.864

0.503

3.) In the same population, if it is under Hardy-Weinberg equilibrium, how many individuals do you expect to be heterozygous at TYRP1?

150

0.500

261

75

4.) Rabbit’s ears can be either short (dominant) or floppy (recessive). If a population of rabbits in Hardy-Weinberg equilibrium has 250 short eared rabbits and 100 floppy eared rabbits, what is the allele frequency of the “short” allele?

0.714

0.465

0.845

0.535

a.

Different alleles of a gene

b.

Varying distances between genes

c.

Natural selection

D. None of the above

2.) Crossing true breeding dark-coated sheep with true breeding light-coated sheep always results in 100% dark-coated offspring. You are screening a population of 300 Soay sheep for coat color, and you count 224 dark sheep and 76 light sheep. What is the genotype frequency of the homozygous recessive sheep for TYRP1 gene if the population is in Hardy-Weinberg equilibrium?

a.

0.747

b.

0.253

c.

0.864

d.

0.503

3.) In the same population, if it is under Hardy-Weinberg equilibrium, how many individuals do you expect to be heterozygous at TYRP1?

a.

150

b.

0.500

c.

261

d.

75

4.) Rabbit’s ears can be either short (dominant) or floppy (recessive). If a population of rabbits in Hardy-Weinberg equilibrium has 250 short eared rabbits and 100 floppy eared rabbits, what is the allele frequency of the “short” allele?

a.

0.714

b.

0.465

c.

0.845

d.

0.535

Explanation / Answer

Answer:

1).Natural selection is the differential success of individuals within the population that results from their interaction with their environment. Natural selection leads to the variations of traits among individuals within a species.

Hence, option (c) is correct answer.

2). When dark-coated sheep (DD) crossed with true breeding light- coated (dd), always results in 100% dark-coated offspring (Dd).

The off-springs are formed in 3:1 ratio. (3 are heterozygous dark-coated and 1 is homozygous light coated sheep)

According to the question given, you are screening a population of 300 Soay sheep for coat colour, and you count 224 dark sheep and 76 light sheep, the genotypic frequency of the homozygous recessive sheep for TYRP1 gene is,

Dd = 76/300 = 0.253.

Hence, option (b) is correct answer.

3). Number of heterozygous individuals is in the ratio of 1: 2: 1 = 300

                                          2x = 150

                                            X = 75

Hence, option (d) is the correct answer.

4). Short eared rabbit (dominant) = 250

Floppy eared rabbits (recessive) = 100

Genotypic frequency of recessive allele = 100/ 250 = 0.285

Allele frequency of recessive allele q = 0.533

                                                          P = (1- 0.533) = 0.465

Hence, option (b) is correct answer.