The recessive characters are -

Options

A. Only expressed in heterozygous condition
B. Only expressed in homozygous condition
C. Blend in heterozygous condition
D. Always impure

Answer

To answer the question regarding recessive characters, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Alleles**:
- Alleles are different forms of a gene. For any trait, there are typically two alleles: one dominant and one recessive.

2. **Dominant vs. Recessive Alleles**:
- The dominant allele is expressed in the phenotype (observable traits) even if only one copy is present (heterozygous condition).
- The recessive allele is only expressed when two copies are present (homozygous condition).

3. **Identifying Heterozygous and Homozygous Conditions**:
- Heterozygous condition: An individual has one dominant and one recessive allele (e.g., Tt).
- Homozygous condition: An individual has two identical alleles, either dominant (TT) or recessive (tt).

4. **Expression of Recessive Characters**:
- Recessive characters are expressed only in the homozygous condition (e.g., tt). They are not expressed in the presence of a dominant allele (e.g., Tt).

5. **Evaluating the Given Options**:
- Option 1: "Expressed only in heterozygous condition" - Incorrect, as recessive traits are not expressed in heterozygous conditions.
- Option 2: "Expressed only in homozygous condition" - Correct, as recessive traits require two copies to be expressed.
- Option 3: "Blend in heterozygous condition" - Incorrect, as blending does not occur; the dominant trait masks the recessive trait.
- Option 4: "Always impure" - Incorrect, as recessive traits can be pure (homozygous).

6. **Conclusion**:
- The correct answer is that recessive characters are expressed only in homozygous conditions.

### Final Answer:
The recessive characters are expressed only in homozygous condition.

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