Which of the following invertebrates shows sexual dimorphism?

Options

A. Ascaris
B. Taenia
C. Starfish
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Sexual Dimorphism**: Sexual dimorphism refers to the differences in appearance between male and female individuals of the same species. This can include differences in size, color, or structure.

2. **Identifying the Invertebrates**: The question provides several invertebrate options. We need to evaluate each one to see if they exhibit sexual dimorphism.

3. **Evaluating Ascaris**:
- Ascaris is a type of roundworm that belongs to the phylum Nematoda.
- In Ascaris, males and females have distinct differences in size and structure. Males are typically smaller and have a curved tail, while females are larger and straight.
- Therefore, Ascaris exhibits sexual dimorphism.

4. **Evaluating Tinea**:
- Tinea refers to a group of parasitic flatworms (tapeworms).
- In Tinea, both male and female reproductive structures can be found within the same individual, indicating that they are hermaphroditic.
- Thus, Tinea does not show sexual dimorphism.

5. **Evaluating Starfish**:
- Starfish are echinoderms and typically do not exhibit sexual dimorphism.
- They have both male and female reproductive organs in some species, and there are no significant differences in appearance between the sexes.
- Therefore, starfish do not show sexual dimorphism.

6. **Conclusion**: Based on the evaluations, the only invertebrate that shows sexual dimorphism is Ascaris.

**Final Answer**: Ascaris shows sexual dimorphism.

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