Homozygous purelines in cattle can be obtained by

Options

A. mating of related individuals of same breed
B. mating of unrelated individuals of same breed
C. mating of individuals of different breed
D. mating of individuals of different species

Answer

To determine how homozygous pure lines in cattle can be obtained, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Homozygosity**:
- Homozygous pure lines refer to individuals that have identical alleles for a particular trait. This can be either dominant homozygous (AA) or recessive homozygous (aa).

2. **Types of Breeding**:
- There are two main types of breeding strategies: inbreeding and outbreeding.
- Inbreeding involves mating individuals that are closely related within the same breed, while outbreeding involves mating unrelated individuals of the same species or individuals from different breeds or species.

3. **Inbreeding**:
- Inbreeding is the process that increases homozygosity. By mating related individuals, the chances of offspring inheriting the same alleles from both parents are increased, leading to a higher probability of producing homozygous individuals.

4. **Evaluating Options**:
- The question provides four options:
1. Mating of related individuals of the same species (Inbreeding)
2. Mating of unrelated individuals of the same species (Outbreeding)
3. Mating of individuals of different breeds (Outcrossing)
4. Mating of individuals of different species (Interspecific hybridization)
- Among these, only the first option (mating of related individuals of the same species) corresponds to inbreeding, which is the correct method to obtain homozygous pure lines.

5. **Conclusion**:
- Therefore, the correct answer is that homozygous pure lines in cattle can be obtained by **inbreeding**.

### Final Answer:
Homozygous pure lines in cattle can be obtained by **mating of related individuals of the same species (Inbreeding)**.

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