The terms frond is used for

Options

A. Rachis
B. Whole plant
C. Spore bearing leaf
D. Sexually reproducing structures.

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Frond":**
- The term "frond" is specifically associated with certain types of plants, particularly ferns. It refers to a specific structure within these plants.

2. **Identifying the Plant Group:**
- Fronds are primarily found in ferns, which belong to the phylum Pteridophyta. This group of plants is characterized by their vascular tissues and the absence of seeds.

3. **Characteristics of Fronds:**
- Fronds are typically large, divided leaves that can have a complex structure. They often display a pattern of venation and can be tightly coiled when they first emerge.

4. **Function of Fronds:**
- In ferns, fronds serve as the spore-bearing structures. They are responsible for the reproduction process, as they bear sporangia that produce spores.

5. **Analyzing the Options:**
- a. Rachis: This term refers to the central stem of a frond, not the frond itself.
- b. The whole plant: This is too broad, as the frond is just a part of the fern.
- c. Spore bearing leaf: This is the correct definition of a frond, as it specifically refers to the leaf structure that bears spores.
- d. Sexually reproducing structure: While fronds are involved in reproduction, they are not the direct structure for sexual reproduction.

6. **Conclusion:**
- Based on the analysis, the correct answer is **option C: spore bearing leaf**. The term "frond" is used to describe the leaves of ferns that are specialized for spore production.