Sieved septa/trumpet hyphae occur in

Options

A. kelps
B. All green algae
C. All red algae
D. Marine algae.

Answer

### Step-by-Step Solution:

1. **Understanding the Terms**: The question asks about "sieved septa" and "trumpet hyphae." These terms are associated with certain types of structures found in specific organisms.

2. **Identifying the Options**: The options given are:
- A) Calps
- B) All green algae
- C) All red algae
- D) Marine algae

3. **Analyzing Each Option**:
- **Calps**: These are large brown algae that belong to the family Laminariaceae. They are known to have conducting tubes that contain sieve septa and trumpet hyphae.
- **All Green Algae**: Green algae belong to the division Chlorophyta. They do not have sieve septa or trumpet hyphae.
- **All Red Algae**: Red algae belong to the division Rhodophyta. They also do not possess these structures.
- **Marine Algae**: This is a broad category that includes various types of algae, but not all marine algae have sieve septa or trumpet hyphae.

4. **Conclusion**: Based on the analysis, the correct answer is **A) Calps**, as they are the only group among the options that possess sieve septa and trumpet hyphae.

5. **Explanation of Structures**:
- **Sieved Septa**: These are specialized structures that have pores, allowing for the conduction of food materials.
- **Trumpet Hyphae**: These are hyphae with bulging ends that connect with other hyphae, also involved in the conduction process.