What is the probability that a gamete egg or spermfrom this

What is the probability that a gamete (egg or sperm)from this population carries a C^R allele? That a gamete from this population carries a C^w allele? Of all the offspring resulting from all the matings in this population, what percentage should have the genotype C^RC^R? What percentage should have the genotype C^WC^W? What percentage should have the genotype C^RC^W? Comparing p and q in parents and offspring In the offspring generation, what is the frequency of the C^R allele? In the offspring generation, what is the frequency of the C^W allele?

Solution

1. The probability that a gamete (egg or sperm) from this population carries a C^R allele is

2. That a gamete from this population carries a C^W allele is

3. Of all the offspring resulting from all the matings in this population, the percentage of C^RC^R genotype is

the frequency(p) of the C^R allele is 0.8

the probability of a C^RC^Roffspring is p²

so C^RC^R (p²) = 0.8 × 0.8 = 0.64, or 64%

4. The genotype C^WC^W percentage is

C^W=0.2

q² =

C^WC^W= 0.2 × 0.2 = 0.04, or 4%.

5. Percentage of C^RC^W genotype is

The probability of heterozygous genotype with a C^RC^W genotype is 0.8 × 0.2 = 0.16

and for C^WC^R genotype is 0.2 × 0.8 = 0.16

Therefore,

0.16 + 0.16 = 0.32 or 32% (for C^RC^W + C^WC^R)

or you can say that the probability of a C^RC^Woffspring is 2pq= 2 x 0.8 x 0.2=0.32

6. The frequency(p) of the C^R allele in the offspring generation is

7. The frequency(q) of the C^W allele in the offspring generation is

POINTS TO REMEMBER

If a population that has two alleles with frequencies p and q, then the total

frequencies of that population must be equal to 1, or 100% which means p + q = 1 so p = 1 q and q = 1 p.

The genotype frequencies must be equal to 1

p² + 2pq + q² = 1

0.64 + 0.32 + 0.04 = 1.0

80%