Which genotype represents a true hybrid condition

Options

A. TTrr
B. TtRr
C. TTRr
D. ttrr

Answer

To determine which genotype represents a true hybrid condition, we need to understand the definitions of hybrid and homozygous conditions.

### Step-by-Step Solution:

1. **Understand the Definitions**:
- A **hybrid** condition occurs when an organism has two different alleles for a particular gene, which is known as a **heterozygous** condition (e.g., Tt).
- A **homozygous** condition occurs when an organism has two identical alleles for a gene (e.g., TT or tt).

2. **Identify the Alleles**:
- In the context of Mendel's pea plants, we can denote the alleles for the stem height gene as:
- **T** (dominant allele for tall plants)
- **t** (recessive allele for dwarf plants)

3. **Analyze the Genotypes**:
- We can have three possible genotypes for the T gene:
- **TT** (homozygous dominant)
- **tt** (homozygous recessive)
- **Tt** (heterozygous or hybrid)

4. **Evaluate the Options**:
- When presented with options, we need to look for a genotype that includes both a dominant and a recessive allele, indicating a hybrid condition.
- For example, if we have two genes (T and R), we need to check if both genes are in a heterozygous condition.

5. **Determine the True Hybrid Condition**:
- The true hybrid condition would be represented by a genotype where both genes are heterozygous, such as TtRr, where T and R are different alleles.
- If any of the genes are homozygous (like TT or tt), it cannot be considered a true hybrid condition.

6. **Conclusion**:
- The genotype that represents a true hybrid condition is the one where both genes are heterozygous, for example, TtRr.

### Final Answer:
The true hybrid condition is represented by the genotype where both alleles are different, such as TtRr.

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