Complex post fertilization development is seen in which algae :-

Options

A. Green algae
B. Brown algae
C. Yellow algae
D. Red algae

Answer

**Step-by-Step Solution:**

1. **Understanding Post-Fertilization Development:**
- Post-fertilization development refers to the processes that occur after the fertilization of gametes, leading to the formation of a new organism.

2. **Identifying the Type of Algae:**
- The question specifically asks for algae that exhibit complex post-fertilization development.

3. **Recognizing the Characteristics of Red Algae:**
- Red algae (Rhodophyta) are known for their unique reproductive structures and processes. They exhibit oogamy, which means they have non-motile male and female gametes.

4. **Describing the Gametes:**
- In red algae, both the male and female gametes are non-motile. The male gamete does not have flagella, which is a key characteristic of red algae.

5. **Explaining the Fertilization Process:**
- When fertilization occurs, the fusion of the non-motile gametes leads to the formation of a zygote that is diploid (2N).

6. **Mitosis and Meiosis in Red Algae:**
- After the formation of the zygote, instead of undergoing direct meiosis, the zygote first undergoes mitosis, resulting in two diploid cells (2N).
- Subsequently, meiosis occurs, producing haploid (N) cells.

7. **Formation of Gametophytes:**
- The diploid cells will develop into female gametophytes, while the haploid cells will develop into male gametophytes.

8. **Conclusion:**
- The entire life cycle of red algae is characterized by these complex post-fertilization processes, which are primarily facilitated by water currents since the male gametes need to reach the non-motile female gametes.

9. **Final Answer:**
- Therefore, the algae that exhibit complex post-fertilization development is **red algae**.

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