Match column A with column B. 

Column A (Type of algae)		Column B (Proper Name)
(a)	Blue-green algae	(i)	Sargassum
(b)	Red algae	(ii)	Chlamydomonas
(c)	Green algae	(iii)	Rhodophyta
(d)	Brown algae	(iv)	Cyanobacteria

The correct answer is a - iv, b - iii, c - ii, d - i.

Key Points

• Blue-green Algae (Cyanobacteria)
  • Blue-green algae are actually bacteria and are also known as Cyanobacteria.
  • They are photosynthetic organisms and can live in a wide variety of environments, including freshwater, seawater, damp soil, or rocks.
  • Cyanobacteria are known for their significant contribution to the Earth's oxygen atmosphere.
  • They can exist as single cells or can form colonies.
• Red Algae (Rhodophyta)
  • Red algae, often called Rhodophyta, have been identified as one of the oldest groups of eukaryotic algae.
  • They are mostly found in the warmer waters of the ocean.
  • Red algae are of great economic value because of their use in the production of agar and carrageenan, substances used as thickening agents in various food products.
  • Their red colour is due to the pigment, phycoerythrin.
• Green Algae (Chlamydomonas)
  • Green algae are a diverse group of algae from which plants evolved. Chlamydomonas is a genus of unicellular green algae.
  • Chlamydomonas species are widely distributed worldwide and are found in soil and freshwater.
  • They have two flagella that allow them to move.
  • They are known for their green colour due to the presence of chlorophyll.
• Brown Algae (Sargassum)
  • Brown algae are the most complex type of algae; many are seaweeds.
  • Sargassum is a brown algae, known for forming massive floating forests in the ocean.
  • It is primarily marine and is found in warm-temperate and tropical oceans.
  • They provide important ecological functions such as providing habitats for a wide variety of marine species.
  • The brown colour is due to the presence of a pigment called fucoxanthin, which masks the green colour of chlorophyll.