Bryophytes are amphibians of plant kingdom.

Answer

### Step-by-Step Text Solution:

1. **Understanding Bryophytes**: Bryophytes are non-vascular plants that are often referred to as the "amphibians of the plant kingdom." This is because they thrive in both terrestrial and aquatic environments.

2. **Habitat Requirements**: Bryophytes typically grow in moist environments. They can be found in soil, on rocks, and in shady areas where there is sufficient moisture.

3. **Reproduction**: Bryophytes require water for reproduction. They can reproduce both sexually and asexually. For sexual reproduction, bryophytes produce male gametes (sperms) that need to swim through water to reach female gametes (eggs).

4. **Sperm Movement**: The sperm cells of bryophytes are motile and swim in water to fertilize the eggs. This swimming motion is essential for the sexual reproduction process.

5. **Life Cycle**: The life cycle of bryophytes includes a dominant gametophyte stage, which is the green, leafy part that we typically see. The sporophyte stage, which is dependent on the gametophyte, produces spores for asexual reproduction.

6. **Conclusion**: Bryophytes are called the amphibians of the plant kingdom because they require water for their reproductive processes and can live in both terrestrial and aquatic habitats.