1. Within a population of butterflies, the color brown (B) isdominant over the c

Question

1. Within a population of butterflies, the color brown (B) isdominant over the color white, and 40% of all butterflies arewhite.
a) Calculate the percentage of butterflies in the population thatare heterozygous b
b) Calculate the frequency of homozygous dominant individuals

2. A very large population of randomly mating laboratory micecontains 35% white mice. White coloring is caused by the doublerecessive genotype "aa". Calculate all allele and genotypefrequencies for this population.

3. The ability to taste a bitter chemical known as PTC is due tothe single dominant allele "T". YOu sampled 215 individuals anddetermined that 150 could detect the bitter taste of PTC and 65could not. Calculate all the potential frequencies.

Explanation / Answer

1) The first thing you'll need to do is obtain p and q. So,since white is recessive (i.e. bb), and 40% of the butterflies arewhite, then bb = q2 = 0.4. To determine q, which is thefrequency of the recessive allele in the population, simply takethe square root of q2 which works out to be 0.632 (i.e.0.632 x 0.632 = 0.4). So, q = 0.63. Since p + q = 1, then p must be1 - 0.63 = 0.37. Now then, to answer our questions. First, what isthe percentage of butterflies in the population that areheterozygous? Well, that would be 2pq so the answer is 2 (0.37)(0.63) = 0.47. Second, what is the frequency of homozygous dominantindividuals? That would be p2 or (0.37)2 =0.14. 2. q^2 = 0.35, so calculate the frequencies exactlylike we did in #1 3. 65/215 are homozygous recessive, so q^2 = 65/215 = 0.302, sousing this information, calculate the frequencies exactly like wasdone in #1 and #2.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.