Question

Give an example of a free-living nitrogen-fixing cyanobacteria.

Answer 1

Nitrogen Fixation:

1. The biological process of nitrogen fixation is the first step in the nitrogen cycle.
2. Certain bacterial species such as Rhizobium, Azotobacter, and others, as well as natural events, transform nitrogen in the atmosphere into ammonia (another form of nitrogen).

Cyanobacteria:

1. Blue-green algae, commonly known as cyanobacteria, are a form of photosynthetic bacteria that can be found as single cells or colonies.
2. Chlorophyll a, a green pigment, is the only kind of chlorophyll found in cyanobacteria.
3. They also include carotenoids and phycobilin, which are colourful pigments.
4. These bacteria can be found in both marine and freshwater environments.
5. Dams, rivers, reservoirs, lakes, and even hot springs are ideal habitats for them.

Example:

1. Anabaena is an example of a free-living nitrogen-fixing cyanobacteria.