According to five kingdom system the unicellular algae like Dinoflagellates, Diatoms and Euglenoids are included in kingdom :-

Options

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

Answer

To solve the question regarding the classification of unicellular algae like Dinoflagellates, Diatoms, and Euglenoids in the five kingdom system, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Five Kingdom System**: The five kingdom classification system was proposed by Robert Whittaker and includes Monera, Protista, Fungi, Plantae, and Animalia. Each kingdom categorizes organisms based on their cellular organization, nutrition, and reproduction.

2. **Identify the Characteristics of Unicellular Algae**: Unicellular algae are primarily photosynthetic organisms that can be found in various aquatic environments. They are eukaryotic, meaning they have a defined nucleus and organelles.

3. **Classify Dinoflagellates, Diatoms, and Euglenoids**:
- **Dinoflagellates**: These are mostly marine organisms known for their role in red tides and are photosynthetic.
- **Diatoms**: These are also photosynthetic and are significant producers in aquatic ecosystems, known for their silica cell walls.
- **Euglenoids**: For example, Euglena, which can photosynthesize in the presence of sunlight and can also feed on organic matter when light is not available.

4. **Determine the Correct Kingdom**: Based on their characteristics, all three groups (Dinoflagellates, Diatoms, and Euglenoids) are classified under the kingdom **Protista**. This kingdom includes all unicellular eukaryotes, which are distinct from the prokaryotic organisms found in the Monera kingdom.

5. **Conclusion**: Therefore, the unicellular algae like Dinoflagellates, Diatoms, and Euglenoids are included in the kingdom **Protista**.

### Final Answer:
The unicellular algae like Dinoflagellates, Diatoms, and Euglenoids are included in the kingdom **Protista**.

---