In mammals the sheep , cow, rat etc. show reproduction during

Options

A. Oestrus phase
B. Anoestrous phase
C. Menstrual phase
D. Diapause phase

Answer

### Step-by-Step Solution:

1. **Identify the Organisms**: The question mentions mammals like sheep, cow, and rat. These animals belong to the class Mammalia.

2. **Understand the Reproductive Cycles**: In mammals, there are two main types of reproductive cycles:
- **Menstrual Cycle**: Found in primates (e.g., humans, monkeys, apes). This cycle involves a monthly preparation of the female body for potential pregnancy.
- **Estrous Cycle**: Found in non-primates (e.g., sheep, cows, rats). This cycle is characterized by specific periods of receptivity to mating, known as the estrous phase.

3. **Differentiate Between Estrous and Anestrous Phases**:
- **Estrous Phase**: This is the period when the female is fertile and receptive to mating. It occurs in non-primates.
- **Anestrous Phase**: This is a period of reproductive inactivity when the female is not in heat and cannot conceive.

4. **Consider Other Options**:
- **Menstrual Phase**: This is specific to primates and does not apply to the mentioned animals.
- **Diapause**: This is a state of suspended development that can occur in some species but is not the primary reproductive phase for the animals in the question.

5. **Conclusion**: Since sheep, cows, and rats are non-primates, they exhibit reproduction during the **estrous phase**. Therefore, the correct answer is the **estrous phase**.

### Final Answer:
In mammals like sheep, cow, and rat, reproduction occurs during the **estrous phase**.

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