Which of the following is the method of vegetative reproduction in algae?

Which of the following algae are used as food supplements by space travellers?

Zygospore is

The number of thylakoids per granum is one in:

Assertion : Red algae contribute to the production of coral reefs.
Reason : Some red algae secrete and deposit calcium carbonate over their walls.

The cell wall of algae is composed of which of the following?