Question

Zoochlorellae and zooxanthellae present in Hydra are

• A. Symbionts in nutritive cells
• B. Symbionts in the gut
• C. Symbionts in fibroblasts
• D. Organisms that provide water

Answer 1

The correct option is A Symbionts in nutritive cells

Zoochlorella is a small green alga that lives within the bodies of various freshwater protozoans and invertebrates and gives colour their hosts green

Zooxanthellae is a member of Dinoflagellata. They perform photosynthesis, live symbiotically with protozoans or on other sea creatures where they provide the host with organic food synthesised by photosynthesis and host provide them with the attachment, protection etc. An organism like Hydra has green or brown colour due to the presence of zoochlorellae and zooxanthellae in their nutritive cells. Thus, the correct answer is option A.