Which marine algae produce large amounts of hydrocolloids ( water holding substances ) ?

Options

A. brown and green
B. brown and red
C. green and red
D. only brown

Answer

To solve the question about which marine algae produce large amounts of hydrocolloids (water holding substances), we can follow these steps:

### Step-by-Step Solution:

1. **Understand Hydrocolloids**: Hydrocolloids are substances that can hold water and are often used in food and industrial applications. They are derived from various sources, including marine algae.

2. **Identify Types of Marine Algae**: The main types of marine algae include:
- Brown algae (Phaeophyceae)
- Red algae (Rhodophyta)
- Green algae (Chlorophyta)

3. **Research Hydrocolloid Production**:
- Brown algae are known to produce alginates, which are hydrocolloids used in food and other industries.
- Red algae produce carrageenan, another type of hydrocolloid that is widely used.

4. **Evaluate the Options**: The question provides several options:
- Brown and green algae
- Brown and red algae
- Green and red algae
- Only brown algae

5. **Select the Correct Answer**: Since both brown algae (producing alginates) and red algae (producing carrageenan) are known for their hydrocolloid production, the correct answer is:
- **Brown and red algae**

### Final Answer:
Brown and red algae produce large amounts of hydrocolloids (water holding substances).

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