A New Kind of Tulip Is Produced That Develops Only

Question

Examlex · Accepted Answer

The Answer is a. Determine the frequency of the purple and pink alleles in this field population.

To determine the frequency of the purple and pink alleles, we can use the Hardy-Weinberg principle, which states that the allele frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. According to this principle, the frequency of the two alleles should add up to 1 (or 100%).

Let p be the frequency of the dominant purple allele (C), and q be the frequency of the recessive pink allele (c). The Hardy-Weinberg principle also states that the genotype frequencies in the population can be represented as p^2 for the homozygous dominant (CC), 2pq for the heterozygous (Cc), and q^2 for the homozygous recessive (cc).

Given that we have 153 pink flowering plants, which are homozygous recessive (cc), we can calculate the frequency of the recessive allele (q^2) as follows:

q^2 = number of pink flowering plants / total number of plants
q^2 = 153 / 1000
q^2 = 0.153

To find q, we take the square root of q^2:

q = √0.153
q ≈ 0.391

Now, since p + q = 1, we can calculate p:

p = 1 - q
p = 1 - 0.391
p ≈ 0.609

Therefore, the frequency of the dominant purple allele (C) is approximately 0.609, and the frequency of the recessive pink allele (c) is approximately 0.391 in the field population.

b. Estimate the proportion of all purple flowering plants that are heterozygotes and homozygotes.

We know that the purple flowering plants can be either homozygous dominant (CC) or heterozygous (Cc). To find the proportion of each, we use the Hardy-Weinberg genotype frequencies:

The proportion of homozygous dominant (CC) is p^2:

p^2 = (0.609)^2
p^2 ≈ 0.371

The proportion of heterozygous (Cc) is 2pq:

2pq = 2 * (0.609) * (0.391)
2pq ≈ 0.476

Since the total number of purple flowering plants is 847, we can calculate the estimated number of each genotype:

Homozygous dominant (CC) = p^2 * total purple plants
Homozygous dominant (CC) ≈ 0.371 * 847
Homozygous dominant (CC) ≈ 314

Heterozygous (Cc) = 2pq * total purple plants
Heterozygous (Cc) ≈ 0.476 * 847
Heterozygous (Cc) ≈ 403

Therefore, out of the 847 purple flowering plants, approximately 314 are estimated to be homozygous dominant (CC), and approximately 403 are estimated to be heterozygous (Cc). Note that due to rounding, these numbers may not add up exactly to 847.

A New Kind of Tulip Is Produced That Develops Only

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