Which protist possesses two flagella one lies longitudinal and other transversely?

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a specific type of protist that has two flagella, with one positioned longitudinally and the other transversely.

2. **Identifying the Kingdom**: We start by recognizing that the organism in question belongs to the kingdom Protista, which consists of unicellular eukaryotic organisms.

3. **Exploring Protista Divisions**: Within the kingdom Protista, we look for divisions that might contain organisms with two flagella. One relevant division is Chrysophyta.

4. **Defining Chrysophyta**: Chrysophyta is known for its members called golden algae. This division includes various types of algae, which can be important for our search.

5. **Identifying Classes within Chrysophyta**: Within Chrysophyta, we focus on the class Dinoflagellates. The name itself suggests the presence of two flagella.

6. **Understanding Dinoflagellates**: Dinoflagellates are characterized by having two flagella positioned at right angles to each other—one longitudinal and one transverse. This unique feature allows them to move in a distinctive manner.

7. **Examples of Dinoflagellates**: Some examples of dinoflagellates include Gymnodinium and Glenodinium, both of which exhibit the described flagellar arrangement.

8. **Conclusion**: Based on the above steps, we conclude that the protist that possesses two flagella, one longitudinal and one transverse, is the dinoflagellate.

**Final Answer**: Dinoflagellates.

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