A cross between two tall plants resulted in offspring having few dwarf plants. What would be the genotypes of both the plants ?

Options

A. TT and Tt
B. Tt and Tt
C. TT and TT
D. Tt and tt

Answer

To determine the genotypes of the two tall plants that resulted in a few dwarf plants in their offspring, we can analyze the inheritance patterns of the traits involved.

### Step-by-Step Solution:

1. **Understanding the Trait**:
- In this scenario, tall (T) is dominant over dwarf (t). Therefore, any plant with at least one dominant allele (T) will be tall.

2. **Offspring Observation**:
- The offspring from the cross between two tall plants resulted in a few dwarf plants. This indicates that the tall parent plants must carry the recessive allele (t) in their genotype.

3. **Possible Genotypes**:
- The possible genotypes for tall plants are:
- Homozygous dominant (TT)
- Heterozygous (Tt)

4. **Analyzing the Cross**:
- If both parent plants were homozygous dominant (TT), all offspring would be tall (TT), and there would be no dwarf plants.
- If both parent plants were heterozygous (Tt), the offspring would be in a 3:1 ratio (3 tall: 1 dwarf).
- If one parent was heterozygous (Tt) and the other was homozygous recessive (tt), the offspring would be in a 1:1 ratio (1 tall: 1 dwarf).

5. **Conclusion**:
- Since the offspring included a few dwarf plants, the most likely scenario is that both parent plants were heterozygous (Tt). This would lead to a ratio of 3 tall plants to 1 dwarf plant in the offspring.

### Final Genotypes:
- The genotypes of both tall plants are **Tt (heterozygous)**.