Question

Which of the following is incorrect about cyanobacteria?

• A. They are photoautotrophs
• B. They lack heterocysts
• C. They often form blooms in polluted water bodies
• D. They have chlorophyll a similar to green plants

Answer 1

The correct option is B They lack heterocysts

Cyanobacteria are photoautotrophs capable of synthesizing food.

They have chlorophyll a similar to green plants in addition to other photosynthetic pigments that trap the radiant energy from the sun.

Certain species of cyanobacteria are capable of fixing atmospheric nitrogen in specialized cells called heterocysts. Example: Nostoc and Anabaena.

Hence the statement in option b is incorrect.

An algal bloom is a rapid increase or accumulation of the planktonic (free-floating) algae such as cyanobacteria in aquatic environments. Presence of excess nutrients like phosphorus and nitrogen in the polluted waters is responsible for this.