Highest degree of polymorphism is found in
(a) Protozoa
(b) Cnidaria
(c) Platyhelminthes
(d) Arthropoda

Options

A. Protozoa
B. Cnidaria
C. Platyhelminthes
D. Arthropoda.

Answer

To solve the question regarding which group exhibits the highest degree of polymorphism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Polymorphism**:
- Polymorphism refers to the occurrence of multiple morphological forms within a species. This means that individuals can have different shapes, sizes, or forms.

2. **Evaluate the Options**:
- **(a) Protozoa**: These are unicellular organisms and typically do not exhibit polymorphism to a significant degree.
- **(b) Cnidaria**: This group includes organisms like jellyfish, corals, and sea anemones. Cnidarians are known for their polymorphism, as they can exist in two main forms: the polyp (asexual form) and the medusa (sexual form).
- **(c) Platyhelminthes**: These are flatworms, which do not show a high degree of polymorphism compared to Cnidaria.
- **(d) Arthropoda**: While arthropods show diversity, they do not exhibit polymorphism in the same way as Cnidaria.

3. **Identify the Correct Answer**:
- Based on the understanding of polymorphism and the evaluation of the options, the group that exhibits the highest degree of polymorphism is **(b) Cnidaria**.

4. **Conclusion**:
- Therefore, the correct answer to the question is **(b) Cnidaria**.