To answer the question regarding the important characters of a specific group of plants, we can analyze the features mentioned:
1. **Multicellular sex organs**: This indicates the presence of specialized reproductive structures, which are typically found in certain plant groups.
2. **Formation of embryo**: This suggests that the group in question has a life cycle that includes the development of an embryo from a zygote.
3. **Dominant gametophytic phase**: This means that the gametophyte stage is the main phase of the life cycle, which is a key characteristic of certain plants.
4. **Requirement of water during sexual reproduction**: This indicates that the fertilization process relies on water, which is essential for the movement of sperm to the egg.
5. **Absence of true roots, stems, and leaves**: This suggests that the plants do not have the typical structures found in higher plants.
Now, let's analyze these characteristics step by step to identify the correct group of plants:
### Step 1: Identify the plant groups
The options provided are Bryophytes, Pteridophytes, Angiosperms, and Gymnosperms.
### Step 2: Analyze Bryophytes
- Bryophytes are known as the amphibians of the plant kingdom because they require water for sexual reproduction.
- They have multicellular sex organs: the male organ is called antheridium, and the female organ is called archegonium.
- The dominant phase in Bryophytes is the gametophyte, which is the photosynthetic part of the plant.
- They do not have true roots, stems, or leaves. Instead, they have structures called rhizoids that anchor them to the substrate.
### Step 3: Analyze other groups
- **Pteridophytes**: These have a dominant sporophyte phase, true roots, stems, and leaves, and do not fit the criteria.
- **Angiosperms**: These also have a dominant sporophyte phase and possess true roots, stems, and leaves.
- **Gymnosperms**: Similar to angiosperms, they have a dominant sporophyte phase and true roots, stems, and leaves.
### Conclusion
Based on the analysis, the characteristics listed in the question match those of **Bryophytes**.
### Final Answer:
The important characters mentioned in the question are characteristic of **Bryophytes**.
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