Which group of protists have a very high number of chromosomes ?

Options

A. Sarcodines
B. Dinoflagellates
C. Sporozoans
D. Ciliates.

Answer

To answer the question "Which group of protists have a very high number of chromosomes?", we will analyze the provided options step by step.

### Step-by-Step Solution:

1. **Identify the Options**: The options given are:
- Option 1: Sarcodines
- Option 2: Dinoflagellates
- Option 3: Sporozoans
- Option 4: Ciliates

2. **Understand Sarcodines**: Sarcodines are known to be free-floating protists that inhabit aquatic environments. They are characterized by their large size and can be multinucleated.

3. **Chromosome Count in Sarcodines**: A specific example of a sarcodine, Allocantha, is noted for having an exceptionally high chromosome count of around 1600 chromosomes. This is significantly higher than the other groups mentioned.

4. **Examine the Other Options**:
- **Dinoflagellates**: While they can have a large number of chromosomes per nucleus (e.g., Alexandrium can have more than 100 per cell), this is still lower than the chromosome count found in sarcodines.
- **Sporozoans**: In sporozoans, the zygote nucleus starts with 12 chromosomes, which reduces to 6 after the first division. This is also lower than the chromosome count in sarcodines.
- **Ciliates**: Ciliates have fragmented macromolecules and do not possess a high number of chromosomes compared to sarcodines.

5. **Conclusion**: Based on the analysis, the group of protists with the highest number of chromosomes is **Sarcodines** (Option 1).

### Final Answer:
The group of protists that have a very high number of chromosomes is **Sarcodines**.

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