Final answer:
The expected proportion of homozygotes among the F2 offspring in a monohybrid cross between AA and aa individuals is 1/4.
Step-by-step explanation:
In a monohybrid cross between AA and aa individuals, the expected proportion of homozygotes among the F2 offspring is 1/4. To understand this, we need to consider the inheritance patterns of alleles. In this case, the A allele is dominant and the a allele is recessive. When we cross AA and aa individuals, all of the F1 offspring will be heterozygous Aa.
When these Aa individuals are crossed with each other, the genotypic ratio of the F2 offspring is expected to be 1 AA: 2 Aa: 1 aa. This means that 1/4 of the F2 offspring will be homozygous, either AA or aa. Therefore, in terms of homozygotes, there is 1 AA individual and 1 aa individual for every 4 offspring, making the proportion of homozygotes 1/2 (or 50%).