Oogamous type of reproduction is seen in
(i) Fucus (ii) Anabaena
(iii) Nostoc (iv) Volvox

Options

A. i only
B. i and ii only
C. i and iii only
D. i and iv only.

Answer

To determine which organisms exhibit oogamous reproduction, let's analyze each option step by step:

1. **Understanding Oogamous Reproduction**:
- Oogamous reproduction is a type of sexual reproduction that involves the fusion of a large, non-motile egg (oocyte) and a small, motile sperm. This is common in many multicellular organisms, particularly in certain algae and plants.

2. **Analyzing Each Option**:
- **(i) Fucus**:
- Fucus is a brown alga that reproduces sexually through oogamy. It has a large egg cell (oogonium) that is fertilized by a motile sperm.
- **Conclusion**: Fucus exhibits oogamous reproduction.

- **(ii) Anabaena**:
- Anabaena is a genus of cyanobacteria that primarily reproduces asexually. It does not have a distinct oogamous reproductive phase; instead, it reproduces through fragmentation and the formation of akinetes (resting spores).
- **Conclusion**: Anabaena does not exhibit oogamous reproduction.

- **(iii) Nostoc**:
- Nostoc is another genus of cyanobacteria that also reproduces asexually. Like Anabaena, it primarily reproduces through the formation of akinetes and does not have an oogamous reproductive cycle.
- **Conclusion**: Nostoc does not exhibit oogamous reproduction.

- **(iv) Volvox**:
- Volvox is a green alga that exhibits oogamous reproduction. It produces large, non-motile eggs that are fertilized by small, motile sperm.
- **Conclusion**: Volvox exhibits oogamous reproduction.

3. **Final Evaluation**:
- Based on the analysis, Fucus and Volvox are the organisms that exhibit oogamous reproduction. Anabaena and Nostoc do not.

4. **Answer Selection**:
- The correct answer is option **(iv) 1 and 4 only** (Fucus and Volvox).

### Summary of the Solution:
- Oogamous reproduction is seen in Fucus and Volvox, while Anabaena and Nostoc reproduce asexually. Therefore, the correct answer is option 4: 1 and 4 only.