Question

in mendel's monohybrid crosses, what is homozygous?
give formula

Answer 1

In Mendel's monohybrid crosses, "homozygous" refers to an organism that has two identical alleles for a particular trait. For instance, if an organism has two dominant alleles (represented as "AA") or two recessive alleles (represented as "aa") for a trait, it is considered homozygous for that trait.

### Formula Representation:
1. **Homozygous Dominant**:
- Genotype: AA
- Alleles: Two copies of the dominant allele.

2. **Homozygous Recessive**:
- Genotype: aa
- Alleles: Two copies of the recessive allele.

### In Contrast:
- **Heterozygous**: An organism with two different alleles for a trait (e.g., Aa).

### Monohybrid Cross Example:
When performing a monohybrid cross between homozygous dominant (AA) and homozygous recessive (aa) parents, the offspring will all be heterozygous (Aa).

The genotype representation can be summarized in a Punnett square:

```
A A
_______
a | Aa | Aa |
|-----|-----|
a | Aa | Aa |
```

In this example, all the offspring have the genotype Aa, displaying the dominant trait due to the presence of the dominant allele A.