All isogamy, anisogamy and oogamy are found in which of the following?

Options

A. Spirogyra
B. Ulothrix
C. Oscillatoria
D. Chlamydomonas

Answer

To solve the question regarding which organisms exhibit isogamy, anisogamy, and oogamy, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Isogamy**: This is a type of sexual reproduction where the gametes are morphologically similar and usually of the same size. Both gametes are typically motile.
- **Anisogamy**: This involves the fusion of gametes that are morphologically dissimilar, usually differing in size. One gamete is typically larger and non-motile (female), while the other is smaller and motile (male).
- **Oogamy**: This is a specific form of anisogamy where the female gamete is large and non-motile (egg), and the male gamete is small and motile (sperm).

2. **Analyzing the Options**:
- **Option A: Spirogyra**: This organism reproduces via isogamy, as it involves the fusion of similar gametes. Therefore, it does not exhibit anisogamy or oogamy.
- **Option B: Ulothrix**: Similar to Spirogyra, Ulothrix reproduces by isogamy only, so it does not meet the criteria for anisogamy or oogamy.
- **Option C: Oscillatoria**: This is a cyanobacterium that primarily reproduces asexually through vegetative methods, hence it does not exhibit any of the three types of gametic fusion.
- **Option D: Chlamydomonas**: This green alga is capable of reproducing through all three methods: isogamy, anisogamy, and oogamy. It can produce similar gametes, dissimilar gametes, and also has a distinct male and female gamete.

3. **Conclusion**: Based on the analysis of the options, the correct answer is **D: Chlamydomonas**. This organism is unique in that it can reproduce through isogamy, anisogamy, and oogamy.

### Final Answer:
**D: Chlamydomonas**