Final answer:
The percentage of individuals that are homozygous recessive for the recessive phenotype in a population where 72 out of 200 individuals express this phenotype is 36%.
Step-by-step explanation:
If 72 out of 200 individuals express the recessive phenotype, then all of these individuals are homozygous recessive. This is because a recessive trait only appears when an individual has two copies of the recessive allele (aa). Therefore, the percentage of individuals that are homozygous recessive is the number of individuals expressing the phenotype divided by the total number of individuals in the population.
Using a simple calculation:
- Number of homozygous recessive individuals = 72
- Total number of individuals = 200
- Percentage of homozygous recessive individuals = (Number of homozygous recessive / Total number of individuals) × 100
- Percentage = (72 / 200) × 100
- Percentage = 36%
Therefore, 36% of the population is homozygous recessive for the trait in question.