Photosensitivity of Euglena is due to

Options

A. Paraflagellar body
B. eye spot
C. Both A and B
D. Chromatophores.

Answer

To answer the question regarding the photosensitivity of Euglena, we can follow these steps:

### Step 1: Understand the Structure of Euglena
Euglena is a unicellular organism that possesses unique structures, including two flagella. One flagellum is long, and the other is short.

**Hint:** Remember that Euglena is a unicellular eukaryote with flagella that aid in movement.

### Step 2: Identify the Role of the Paraflagellar Body
The paraflagellar body is a specialized structure located near the base of the flagella. It is specifically found at the region where the two flagella branches unite.

**Hint:** Focus on the location of the paraflagellar body in relation to the flagella.

### Step 3: Connect Photosensitivity to the Paraflagellar Body
The paraflagellar body plays a crucial role in photosensitivity. It is responsible for receiving light stimuli, which helps Euglena to detect light and move towards it, a behavior known as phototaxis.

**Hint:** Think about how organisms respond to light and the structures that help them do so.

### Step 4: Conclude the Function of the Paraflagellar Body
Since the paraflagellar body is involved in receiving light stimuli and facilitating movement in response to light, we can conclude that the photosensitivity of Euglena is due to this structure.

**Hint:** Summarize the function of the paraflagellar body in relation to light sensitivity.

### Final Answer:
The photosensitivity of Euglena is due to the paraflagellar body, which is located at the region of union of the flagellar branches. This structure receives light stimuli and enables the organism to move towards light sources.

---