Here's why:
* Homozygous dominant means the individual has two copies of the dominant allele (AA).
* Homozygous recessive means the individual has two copies of the recessive allele (aa).
When these individuals reproduce, each parent contributes one allele to their offspring.
* The homozygous dominant parent can only contribute an A allele.
* The homozygous recessive parent can only contribute an a allele.
Therefore, all offspring will inherit one A allele from the dominant parent and one a allele from the recessive parent, resulting in the genotype Aa.
In simpler terms:
Imagine the dominant allele is for brown eyes (B) and the recessive allele is for blue eyes (b).
* The homozygous dominant parent has brown eyes (BB).
* The homozygous recessive parent has blue eyes (bb).
All of their children will inherit one B allele and one b allele, making their genotype Bb. Since brown eyes are dominant, all of their children will have brown eyes, even though they carry the recessive blue eye allele.
