How many of the following animals are unisexual [Sponges , Earthworm, Cockroach , Leech , Tapeworm]
a) None
b) One
c) Two
d) Three

Options

A. None
B. One
C. Two
D. Three

Answer

To determine how many of the listed animals are unisexual, we need to analyze each animal one by one:

1. **Sponges**:
- Sponges are primarily hermaphroditic, meaning they possess both male and female reproductive organs in the same individual. Therefore, sponges are not unisexual.

2. **Earthworms**:
- Earthworms are also hermaphrodites. Each individual has both male and female reproductive systems, allowing them to mate with any other earthworm. Thus, earthworms are not unisexual.

3. **Cockroaches**:
- Cockroaches are unisexual. Male and female cockroaches have distinct differences in their reproductive anatomy. Therefore, cockroaches are classified as unisexual.

4. **Leeches**:
- Leeches are similar to earthworms in that they are hermaphroditic, possessing both male and female reproductive organs. Hence, leeches are not unisexual.

5. **Tapeworms**:
- Tapeworms are also hermaphroditic. They have both male and female reproductive structures within the same organism. Therefore, tapeworms are not unisexual.

Now, let's summarize our findings:
- Sponges: Bisexual
- Earthworms: Bisexual
- Cockroaches: Unisexual
- Leeches: Bisexual
- Tapeworms: Bisexual

From this analysis, we find that only **one** animal (the cockroach) is unisexual.

Thus, the answer to the question is:
**b) One**