Read the following characters carefully
(a) Organ system level of organisation
(b) Sexes are separate
(c) Internal fertilization
(d) Bilateral symmetry
(e)Pseudocoelomate
How many animals given below consists of all the characters mentioned above a , b , c , d and e ? Ascaris , Ancyclostoma , Nereis , Earthworm , Taenia , Liver fluke

Options

A. two
B. three
C. four
D. six

Answer

To solve the question, we need to analyze each of the given animals based on the specified characteristics:

1. **Organ system level of organization**: This means that the organism has complex systems (like circulatory, respiratory, etc.) working together.
2. **Sexes are separate**: This indicates that the male and female reproductive organs are found in different individuals.
3. **Internal fertilization**: This means that fertilization occurs inside the female's body.
4. **Bilateral symmetry**: This means that the organism can be divided into two identical halves along one plane.
5. **Pseudocoelomate**: This refers to organisms that have a body cavity (coelom) that is not completely lined by mesoderm.

Now, let's evaluate the given animals:

1. **Ascaris**:
- Organ system level: Yes
- Sexes are separate: Yes
- Internal fertilization: Yes
- Bilateral symmetry: Yes
- Pseudocoelomate: Yes
- **Conclusion**: Ascaris meets all the criteria.

2. **Ancylostoma**:
- Organ system level: Yes
- Sexes are separate: Yes
- Internal fertilization: Yes
- Bilateral symmetry: Yes
- Pseudocoelomate: Yes
- **Conclusion**: Ancylostoma meets all the criteria.

3. **Nereis**:
- Organ system level: Yes
- Sexes are separate: Yes
- Internal fertilization: No (external fertilization occurs)
- Bilateral symmetry: Yes
- Pseudocoelomate: No (it is a coelomate)
- **Conclusion**: Nereis does not meet all the criteria.

4. **Earthworm**:
- Organ system level: Yes
- Sexes are separate: No (it is hermaphroditic)
- Internal fertilization: Yes
- Bilateral symmetry: Yes
- Pseudocoelomate: No (it is a coelomate)
- **Conclusion**: Earthworm does not meet all the criteria.

5. **Taenia**:
- Organ system level: Yes
- Sexes are separate: Yes
- Internal fertilization: Yes
- Bilateral symmetry: Yes
- Pseudocoelomate: No (it is a coelomate)
- **Conclusion**: Taenia does not meet all the criteria.

6. **Liver Fluke**:
- Organ system level: Yes
- Sexes are separate: Yes
- Internal fertilization: Yes
- Bilateral symmetry: Yes
- Pseudocoelomate: No (it is a coelomate)
- **Conclusion**: Liver Fluke does not meet all the criteria.

### Final Count:
From the analysis, only **Ascaris** and **Ancylostoma** meet all the specified characteristics. Therefore, the answer is **2 animals**.