Which one of the following statements is wrong?

Options

A. (a) Agar-agar is obtained from Gelidium and Gracilaria
B. (b) Chlorella and Spirullina are used as space food
C. (c) Mannitol is stored food in Rhodophyceae
D. (d) Algin and carrageenan are products of algae.

Answer

To determine which statement is wrong, we will analyze each option provided in the question step by step.

### Step 1: Analyze the First Statement
The first statement claims that "agar agar is obtained from Gelidium and Gracilaria."
- **Evaluation**: This statement is true. Agar agar is indeed a phycocolloid derived from the cell walls of red algae, specifically from the genera Gelidium and Gracilaria.

### Step 2: Analyze the Second Statement
The second statement states that "Chlorella and Spirulina are used as space food."
- **Evaluation**: This statement is also true. Chlorella and Spirulina are types of green algae known for their high protein content and ability to produce oxygen, making them suitable for use as space food.

### Step 3: Analyze the Third Statement
The third statement claims that "mannitol is stored food in rhodophycin."
- **Evaluation**: This statement is false. Mannitol is actually the stored food in Phaeophyceae (brown algae), while Rhodophyceae (red algae) store food as Floridian starch. Therefore, this statement is incorrect.

### Step 4: Analyze the Fourth Statement
The fourth statement says "algin and carrageenan are products of algae."
- **Evaluation**: This statement is true. Algin is derived from brown algae, and carrageenan is derived from red algae. Both are phycocolloids and are indeed products of algae.

### Conclusion
After evaluating all the statements, the incorrect statement is the third one: "mannitol is stored food in rhodophycin."

### Final Answer
The wrong statement is: **"mannitol is stored food in rhodophycin."**

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