Question

State an important function performed by blue-green algae.

Answer 1

Answer:

The blue-green algae are often referred to as Cyanobacteria or Cyanophyta which is a phylum of Bacteria that obtain their energy through photosynthesis.The name "cyanobacteria" comes from the colour of the bacteria, cyan (blue); the bacteria do not use or produce cyanide. Putative fossil traces of cyanobacteria have been found from around 3.8 billion years which surely proves that Blue-green algae are among the most primitive life forms on Earth.

Blue-green algae are present in almost all aquatic ecosystems, including creeks, rivers, lakes and wetlands. Individual cells are quite small, so blue green algae can be present in a water body without being visible. However, as environmental conditions become just right, algae numbers can start to increase rapidly and blooms, or scums, become easily visible across the water surface. The blooms range in color from dark green to yellowish–brown and develop paint like consistency as they dry out around the water’s edge. A blue pigment may also be seen as they dry.They are in fact prokaryotes, not algae.They share abilities of plants, as they can perform photosynthesis. Also, they have some features of primitive bacteria, which lacked the plant cell wall. Interestingly, they also share characteristics of the animal kingdom as they contain (on their cellular membrane) complex sugars which are quite similar to glycogen. Among blue-green algae we find both edible and toxic species, adaptive to the most extreme habitats on Earth, including deep-seas, hot springs, and Antarctic ice. Edible species have been used by humans as food for thousands of years. Habitats with sufficient algae growth include the Pacific Ocean near Japan and Hawaii, and large freshwater lakes in Africa, North and South America and in

Answer 2

The blue-green algae is Rhizobium bacteria which helps fix atmospheric nitrogen to the soil.

Explanation:

The system of cultivating a leguminous crop between two cereals crops is called crop rotation. Crop rotation is very helpful for the soil because it improves the fertility of the soil by replenishing it with nitrogen and increases the production of food grains. Leguminous plants contain the Rhizobium bacteria which are present in the root nodules of the plant. These bacteria can fix atmospheric nitrogen in the soil . Thus the next crop will require less amount of nitrogen fertilizer.