In plants, homozygous and heterozygous refer to the genetic makeup of an organism for a particular trait. These terms describe the combination of alleles (different forms of a gene) present on homologous chromosomes.
1. Homozygous condition:
- A plant is homozygous when it has two identical alleles for a specific trait.
- Example: If the gene for flower color has two alleles (R for red and r for white), a plant with RR or rr is homozygous.
- Homozygous plants produce offspring with the same trait when self-pollinated.
- These plants are often genetically pure for that trait.
2. Heterozygous condition:
- A plant is heterozygous when it has two different alleles for a specific trait.
- Example: A plant with Rr has one allele for red and one for white flower color.
- The dominant allele (R) expresses itself, so the flower appears red, while the recessive allele (r) is hidden.
- Heterozygous plants can produce offspring with different traits due to genetic variation.
In short:
- Homozygous: Two same alleles (pure for a trait).
- Heterozygous: Two different alleles (mixed for a trait).
These conditions are important in plant breeding, genetics, and understanding inheritance patterns.