What is unique about bryophytes ?

Options

A. They do not have roots
B. Bryophytes produce spores
C. They lack vascular tissues
D. Sporophyte depends upon and remains attached to gametophyte.

Answer

### Step-by-Step Text Solution

1. **Definition of Bryophytes**: Bryophytes are non-vascular plants that include mosses, liverworts, and hornworts. They are unique in their structure and reproductive methods compared to other plant groups.

2. **Non-Vascular Nature**: Bryophytes lack vascular tissues, meaning they do not have xylem and phloem. This absence of vascular tissues limits their size and the way they transport water and nutrients.

3. **Thaloid Structure**: The body of bryophytes is not differentiated into true roots, stems, and leaves. Instead, they have a simple structure known as thallus, which is a characteristic feature of these plants.

4. **Amphibious Nature**: Bryophytes are often referred to as the "amphibians of the plant kingdom" because, although they primarily grow on land, they require water for reproduction, particularly for the process of fertilization.

5. **Gametophyte Dominance**: In bryophytes, the main plant body is the gametophyte, which is haploid (having a single set of chromosomes). This is a unique feature as in most other plants, the diploid sporophyte is the dominant form.

6. **Sporophyte Dependency**: The sporophyte generation in bryophytes is diploid and remains attached to the gametophyte for its entire development. This dependency is a distinctive characteristic that sets bryophytes apart from other plant groups.

7. **Conclusion**: The unique feature of bryophytes is that the sporophyte depends upon and remains attached to the gametophyte for its development. This characteristic highlights their reproductive strategy and lifecycle.