Consider the following statement and select correct set for brown algae as well as red algae.
(i) Certain marine forms produce large amonts of hydrocolloids.
(ii) Used as food supplements by space travellers.
(iii) Organisms may have unicellular and multicellular plant body.
(iv) They have cellulose in cell wall and chlorophyll a pigment.

Options

A. (i) & (iv)
B. (ii) & (iii)
C. (i) & (iii)
D. (iii) & (iv)

Answer

To solve the question regarding the statements about brown algae and red algae, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement (i): Certain marine forms produce large amounts of hydrocolloids.**
- Brown algae and red algae are both primarily marine organisms.
- Brown algae (Phaeophyceae) produce hydrocolloids like algin, which are used as thickening agents in food products.
- Red algae (Rhodophyceae) produce hydrocolloids like carrageenan, which is also used in food and other products.
- **Conclusion:** This statement is correct for both brown and red algae.

2. **Statement (ii): Used as food supplements by space travelers.**
- The statement refers to food supplements used by space travelers.
- Green algae, such as Spirulina and Chlorella, are known to be used as food supplements due to their high protein and nutrient content.
- Brown and red algae are not typically used as food supplements for space travelers.
- **Conclusion:** This statement is incorrect for both brown and red algae.

3. **Statement (iii): Organisms may have unicellular and multicellular plant body.**
- Brown algae are predominantly multicellular, with examples like kelps being large and complex.
- Red algae are also primarily multicellular, although there are some unicellular forms, they are not the majority.
- Since the statement suggests that both types can be unicellular and multicellular, and the majority are multicellular, this statement is misleading.
- **Conclusion:** This statement is incorrect for both brown and red algae.

4. **Statement (iv): They have cellulose in cell wall and chlorophyll a pigment.**
- Both brown algae and red algae have cellulose in their cell walls.
- Chlorophyll a is present in all algae, including brown and red algae, although they may also contain additional pigments (like fucoxanthin in brown algae).
- **Conclusion:** This statement is correct for both brown and red algae.

### Final Conclusion:
- The correct statements for brown algae and red algae are (i) and (iv).
- Therefore, the correct answer is **Option A**.