Two heterozygous parents produce a recessive offspring. Explain.
Two heterozygous parents (Tt × Tt) can produce a recessive offspring because each parent can pass the recessive allele.
Key Idea
| Term | Meaning |
|---|---|
| Heterozygous | Tt (one dominant, one recessive) |
| Recessive Expression | Appears only in tt |
Genetic Cross
| Gametes | T | t |
|---|---|---|
| T | TT | Tt |
| t | Tt | tt |
Result
| Genotype | Probability | Phenotype |
|---|---|---|
| TT | 25% | Dominant |
| Tt | 50% | Dominant |
| tt | 25% | Recessive |
Stepwise Understanding
Each parent produces two types of gametes (T and t)
During fertilization, combinations form randomly
One possible combination is tt
In this case, no dominant allele is present
Recessive trait gets expressed
Important Concept
Recessive traits appear only when both alleles are recessive.
Real Insight
Parents may not show the recessive trait themselves but can still have a child with that trait, which sometimes surprises people.
So recessive offspring appears when both parents pass the recessive allele together.