When we talk about genetic crosses, there are two important terms to know: homozygous and heterozygous. Let’s break it down simply.

• Homozygous:

  • This means an organism has two identical genes for a trait.
  • For example, it could be AA or aa.
  • When these organisms reproduce, all their offspring will have the same gene combinations.

• Heterozygous:

  • This means an organism has two different genes for a trait.
  • For example, it might be Aa.
  • When these organisms reproduce, their offspring can have a mix of gene combinations.
  • If you use a Punnett square for this type, you might see ratios like 1:2:1 when you cross Aa x Aa.

To sum it up, homozygous crosses create traits that are all the same, while heterozygous crosses create more variety in traits. This variety makes genetics really exciting!