Which of the following shows the sexual dimorphism

Options

A. Hydra and Ascaris
B. Hydra and Oryctolaugus
C. Ascaris and Pheretima
D. Ascaris and Orytolagus

Answer

To determine which of the given options shows sexual dimorphism, we need to analyze each pair of organisms based on their characteristics.

### Step-by-Step Solution:

1. **Understanding Sexual Dimorphism**:
- Sexual dimorphism refers to the differences in appearance between males and females of the same species. This can include variations in size, color, shape, and structure.

2. **Analyzing the First Option: Hydra and Ascaris**:
- **Hydra**: This organism is unisexual and does not exhibit sexual dimorphism.
- **Ascaris**: This roundworm shows clear sexual dimorphism, as males and females can be distinguished by their external features.
- **Conclusion**: This option is incorrect because Hydra does not show sexual dimorphism.

3. **Analyzing the Second Option: Hydra and Oryctolagus**:
- **Hydra**: Again, it does not show sexual dimorphism.
- **Oryctolagus**: This is the scientific name for the European rabbit, which does exhibit sexual dimorphism.
- **Conclusion**: This option is incorrect because one organism (Hydra) does not show sexual dimorphism.

4. **Analyzing the Third Option: Ascaris and Ferritima**:
- **Ascaris**: As mentioned, it shows sexual dimorphism.
- **Ferritima**: This is the scientific name for the earthworm, which does not exhibit sexual dimorphism.
- **Conclusion**: This option is incorrect because Ferritima does not show sexual dimorphism.

5. **Analyzing the Fourth Option: Ascaris and Oryctolagus**:
- **Ascaris**: Shows sexual dimorphism.
- **Oryctolagus**: Also shows sexual dimorphism.
- **Conclusion**: This option is correct because both organisms exhibit sexual dimorphism.

### Final Answer:
The correct answer is **Ascaris and Oryctolagus** as both show sexual dimorphism.