statement 1: In heterosporous pteridophytes, development of zygote into young embryo takes place within the female gametophyte.
statement 2: Heterospory is one of the essentiality for seed habit in plants.

Options

A. only statement-1 is correct
B. only statement-2 is correct
C. both the statements are incorrect
D. both the statements are correct

Answer

To solve the question, we need to analyze both statements regarding heterosporous pteridophytes and their role in the seed habit of plants.

### Step-by-Step Solution:

1. **Understanding Heterospory**:
- Heterospory refers to the production of two different types of spores: microspores (male) and megaspores (female). This is a characteristic feature of certain pteridophytes.

**Hint**: Remember that heterospory leads to the formation of male and female gametophytes.

2. **Development of Zygote**:
- In heterosporous pteridophytes, the zygote is formed after the fusion of male and female gametes. The development of this zygote into a young embryo occurs within the female gametophyte. This is an important aspect of the reproductive cycle in these plants.

**Hint**: Focus on the role of the female gametophyte in nurturing the developing zygote.

3. **Importance of Heterospory for Seed Habit**:
- Heterospory is considered an essential step towards the evolution of seed habit in plants. The differentiation of spores allows for the specialization of gametes, which is crucial for the formation of seeds. The male gametophyte produces sperm, and the female gametophyte produces eggs, leading to fertilization and seed development.

**Hint**: Think about how the specialization of spores contributes to reproductive success and seed formation.

4. **Conclusion**:
- Both statements are correct. Statement 1 accurately describes the development of the zygote within the female gametophyte in heterosporous pteridophytes. Statement 2 correctly identifies heterospory as essential for the seed habit in plants.

**Hint**: Summarize the findings to confirm that both statements are true and relate to each other.

### Final Answer:
Both statements are correct. Therefore, the answer is option 4: Both statements are correct.