Question

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

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

Answer 1

1. The correct answer is option (a) - Different alleles of a gene

Alleles undergo recombination during mitosis and meiosis, which leads to variation within a species.

2.

Total no. of sheep - 300

F2 generation

Dark-coloured - 224

Light - 76

The ratio is roughly 3:1

76 sheep are homozygous recessive

q² = 76/300

= 0.253

q = 0.503

Hene, the correct answer is option (d) = 0.503

3.

if q = 0.503

p = 1 - 0.503

= 0.497

Heterozygous individuals = 2pq*300 = 2*0.503*0.497*300

= approx 150 individual

Hence, the option (a) is correct.

4. Total rabits = 350

Short eared = 250

Floppy eared = 100

q² = 100/350 = 0.286

q = 0.535

p = 1-0.535 = 0.465

Hence, the correct answer is option (b)