Red algae are able to grow deep in sea as

Options

A. they can trap blue green light of short wave length in deept layer of water
B. they have clorophyll b to trap blue green light in deept layer of water
C. Both 1 and 2
D. both wrong.

Answer

### Step-by-Step Solution:

1. **Identify the Group**: Red algae belong to the group known as Rhodophyceae. This classification is important as it helps us understand their characteristics and adaptations.

2. **Pigments Present**: Red algae contain chlorophyll A and D, along with a pigment called phycoerythrin. Phycoerythrin is what gives red algae their characteristic red color.

3. **Food Storage**: The stored food in red algae is in the form of Floridian starch and polysulphate esters. This is relevant as it indicates how these organisms store energy.

4. **Light Absorption**: One of the key reasons red algae can grow in deep sea environments is their ability to absorb blue-green light. This type of light has a shorter wavelength, which penetrates deeper into the water compared to other wavelengths.

5. **Correct Option**: Given the options, the first option states that red algae can trap blue-green light of short wavelength in the deeper layers of water. This is correct and aligns with the information about their ability to thrive in deeper waters.

6. **Evaluate Other Options**:
- The second option incorrectly states that red algae have chlorophyll B, which they do not. They only have chlorophyll A and D.
- The third option suggests both options 1 and 2 are correct, which is false since option 2 is incorrect.
- The fourth option states that both options are wrong, which is also incorrect since option 1 is correct.

7. **Conclusion**: Therefore, the correct answer is option 1: Red algae can grow deep in the sea because they can trap blue-green light of short wavelength.