Phytoplankton and zooplankton mostly belong to

Options

A. Monera
B. Protista
C. Animalia
D. Plantae and Animalia.

Answer

### Step-by-Step Solution:

1. **Understanding Phytoplankton**:
- Phytoplankton are small, free-floating organisms that perform photosynthesis. This means they can create their own food using sunlight, similar to plants.
- Examples of phytoplankton include algae such as Chlorella, Chlamydomonas, Spirogyra, and diatoms.

2. **Classification of Phytoplankton**:
- Since phytoplankton are photosynthetic organisms, they belong to the kingdom Plantae. This is because they share characteristics with plants, primarily their ability to produce their own food through photosynthesis.

3. **Understanding Zooplankton**:
- Zooplankton are small, often microscopic organisms that primarily feed on phytoplankton and other small particles in the water. They can be unicellular protists or larger organisms like jellyfish and arrow worms.
- Unlike phytoplankton, zooplankton are heterotrophic, meaning they cannot produce their own food and must consume other organisms.

4. **Classification of Zooplankton**:
- Because zooplankton are heterotrophic and feed on other organisms, they are classified under the kingdom Animalia. This is due to their role as primary consumers in the aquatic food web.

5. **Conclusion**:
- Therefore, phytoplankton belong to the kingdom Plantae, while zooplankton belong to the kingdom Animalia.

### Final Answer:
Phytoplankton belong to the kingdom **Plantae**, and zooplankton belong to the kingdom **Animalia**.

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