In a population of grasshoppers, the color green (G) is completely dominant over the color brown (g). If 23% of the population is brown, calculate the percentage of the population that is expected to be heterozygous

The answer is 49.92%

Let's use the Hardy-Weinberg principle:

p + q = 1

p ² + 2pq + q² = 1

where:

p - the frequency of dominant allele G

q - the frequency of recessive allele g

p² - the frequency of homozygous dominant individuals GG with colour green

2pq - the frequency of heterozygous individuals Gg with colour green

p² - the frequency of homozygous recessive individuals gg with color brown

23% of the population is brown: p² = 23% = 0.23

p = √ (p²) = √0.23 = 0.48

p = 0.48

p + q = 1

0.48 + q = 1

q = 1 - 0.48 = 0.52

The percentage of the population that is expected to be heterozygous is 2pq:

2pq = 2 * p * q = 2 * 0.48 * 0.52 = 0.4992 = 49.92%