In which of these plants , the diploid stage of their life is dependent on the haploid stage of their life ?

Options

A. Riccia , Marchantia
B. Pinus, Cycas
C. Nephrolepis , Adiantum.
D. Hibiscus, Cycas

Answer

To solve the question of which plants have a diploid stage that is dependent on the haploid stage, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Life Cycle of Plants**:
- Plants have two main phases in their life cycle: the haploid phase (gametophyte) and the diploid phase (sporophyte).
- The gametophyte produces gametes (haploid cells), while the sporophyte produces spores.

2. **Identify the Dominance of Phases**:
- In some plants, the sporophyte (diploid) is the dominant phase, while in others, the gametophyte (haploid) is dominant.
- In higher plants, such as gymnosperms and angiosperms, the sporophyte is the dominant phase, and the gametophyte is reduced.

3. **Focus on Bryophytes**:
- Bryophytes (like mosses and liverworts) have a dominant gametophyte phase.
- In bryophytes, the sporophyte is attached to the gametophyte and depends on it for nutrition.

4. **Analyze the Options**:
- The question asks for plants where the diploid stage is dependent on the haploid stage.
- Among the options, look for bryophytes, as they fit the criteria of having a dependent sporophyte.

5. **Conclusion**:
- The correct answer is **option A**, which includes Rixia and Marchantia, both of which are bryophytes where the sporophyte is dependent on the gametophyte.

### Final Answer:
The plants in which the diploid stage (sporophyte) is dependent on the haploid stage (gametophyte) are **Rixia and Marchantia** (Option A).

---