''Nostoc' is a type of:

Concept-

• Bacteria are the sole members of the Kingdom Monera.
• Blue-green algae come under Kingdom Monera.
• Blue-green algae are also known as cyanobacteria.
• Blue-green algae are photosynthetic autotrophs.

Explanation-

• Some of the Blue-green algae can perform Nitrogen fixation.
• Blue-green algae fix nitrogen through specialized cells called heterocysts.
• They convert atmosphere nitrogen into nitrogenous compounds like amino acids, nitrates. These nitrates increase the fertility of the soil.
• Hence blue-green algae improve the fertility of the soil by nitrogen fixation.

Examples of blue-green algae that fix nitrogen are Nostoc.

Important Points

• Cyanobacteria were the first organisms that produced oxygen on our earth.

Additional Information

• Brown algae, green algae, and red algae are the algae that come under Kingdom Plantae.
  • Member of Chlorophyceae is commonly known as 'green algae'.
  • Member of Phaeophyceae is commonly known as 'brown algae'.
  • Member of Rhodophyceae is commonly known as 'red algae'.