In bryophytes, the diploid number of chromosomes occurs in

Options

A. Gametes
B. Spores
C. Nuclei of gametophyte
D. Spore mother cells

Answer

### Step-by-Step Solution:

1. **Understanding Bryophytes**:
- Bryophytes are non-vascular land plants, which include mosses and liverworts. They lack vascular tissues like xylem and phloem.

2. **Life Cycle of Bryophytes**:
- Bryophytes exhibit a life cycle known as alternation of generations, consisting of two distinct phases: the haploid gametophyte phase and the diploid sporophyte phase.
- The gametophyte phase is the dominant phase and is haploid (n), meaning it has a single set of chromosomes.

3. **Identifying the Phases**:
- The **gametophyte** phase (haploid) produces gametes (sperm and eggs).
- The **sporophyte** phase (diploid) produces spore mother cells, which are diploid.

4. **Analyzing the Options**:
- **Gametes**: These are produced in the gametophyte phase and are haploid.
- **Spores**: These are produced from spore mother cells through meiosis and are also haploid.
- **Nuclei of Gametophytes**: These are haploid since they are part of the gametophyte generation.
- **Spore Mother Cells**: These are found in the sporophyte phase and are diploid (2n).

5. **Conclusion**:
- The diploid number of chromosomes in bryophytes occurs in **spore mother cells**.

### Final Answer:
In bryophytes, the diploid number of chromosomes occurs in **spore mother cells**.