Out of the following animals , how many show the oestrous cycle ?
[Lizard , Lion , Goat , Rat , Human , Apes , Monkeys]

Options

A. Four
B. Five
C. Two
D. Three

Answer

To determine how many of the listed animals show the oestrous cycle, we need to understand the definitions and differences between the oestrous cycle and the menstrual cycle.

### Step-by-Step Solution:

1. **Define Oestrous Cycle**: The oestrous cycle is a reproductive cycle found in many non-primates, where females go through periods of heat (oestrus) during which they are receptive to mating. Importantly, there is no menstrual bleeding involved in this cycle.

2. **Define Menstrual Cycle**: The menstrual cycle, on the other hand, is characterized by a monthly cycle of hormonal changes that includes menstruation (bleeding) in primates, including humans.

3. **Identify the Animals**: The animals listed in the question are:
- Lizard
- Lion
- Goat
- Rat
- Human
- Apes
- Monkeys

4. **Classify Each Animal**:
- **Lizard**: Does not have an oestrous cycle; it has different reproductive strategies.
- **Lion**: Shows an oestrous cycle.
- **Goat**: Shows an oestrous cycle.
- **Rat**: Shows an oestrous cycle.
- **Human**: Has a menstrual cycle.
- **Apes**: Have a menstrual cycle.
- **Monkeys**: Have a menstrual cycle.

5. **Count the Animals with Oestrous Cycle**: From the classification:
- Animals showing the oestrous cycle: Lion, Goat, Rat.
- Total: 3 animals.

6. **Final Answer**: Therefore, the number of animals that show the oestrous cycle is **3**.