Dominant and recessive traits in plants describe how certain characteristics are expressed depending on the types of genes (alleles) a plant inherits.
Here’s a simple explanation:
1. Genes and alleles:
Each trait in a plant (like flower color or seed shape) is controlled by a gene, and each gene has two versions called alleles — one from each parent.
2. Dominant traits:
- A dominant trait is the one that shows up even if only one dominant allele is present.
- The dominant allele “masks” or hides the effect of the recessive one.
- Example: In pea plants, the allele for tall plants (T) is dominant.
- So both TT and Tt plants will be tall.
3. Recessive traits:
- A recessive trait appears only when both alleles are recessive.
- The recessive trait is hidden when a dominant allele is present.
- Example: The allele for short plants (t) is recessive.
- Only tt plants will be short.
4. Summary:
| Genotype | Trait expressed (Phenotype) |
|---|---|
| TT | Tall (Dominant) |
| Tt | Tall (Dominant) |
| tt | Short (Recessive) |
In short:
- Dominant traits appear when at least one dominant allele is present.
- Recessive traits appear only when both alleles are recessive.
These patterns of inheritance were first discovered by Gregor Mendel through his experiments with pea plants.