Name the three classes of Algae. Explain its.

1.	Name the three classes of Algae. Explain its.
Answer» • Algae are unicellular like Chlamydomonas, colonial like Volvox or fila mentous like Spirogyra. (i) Chlorophyceae • Green algae. Main pigment is chlorophyll ‘a’ and ‘b’. • Cell wall has inner layer of cellulose and outer layer of pectose. • Has pyrenoids made up of starch and proteins. e.g., Chlamydomona, Volvox, Spirogyra. (ii) Phaeophyceae • Brown algae due to main pigments chlorophyll ‘a’, ‘c’ and fucoxanthin. • Cell wall has cellulose and lignin or gelantinous coating of algin. • Has mannitol and laminarin as reserve food material. • Body divisible into holdfast, stipe and frond. • e.g., Ectocarpus, Fucus, Laminaria. (iii) Rhodophyceae • Red algae due to pigments chlorophyll ‘a’, ‘d’ and r-phycoerythrin. • Found on surface as well as great depths in oceans. • Cell wall as cellulose. • Reserve food material is floridean starch. • e.g., Polysiphonia, Porphyra, Gelidium.

Answer»

• Algae are unicellular like Chlamydomonas, colonial like Volvox or fila mentous like Spirogyra.

(i) Chlorophyceae

• Green algae. Main pigment is chlorophyll ‘a’ and ‘b’.

• Cell wall has inner layer of cellulose and outer layer of pectose.

• Has pyrenoids made up of starch and proteins.

e.g., Chlamydomona, Volvox, Spirogyra.

(ii) Phaeophyceae

• Brown algae due to main pigments chlorophyll ‘a’, ‘c’ and fucoxanthin.

• Cell wall has cellulose and lignin or gelantinous coating of algin.

• Has mannitol and laminarin as reserve food material.

• Body divisible into holdfast, stipe and frond.

• e.g., Ectocarpus, Fucus, Laminaria.

(iii) Rhodophyceae

• Red algae due to pigments chlorophyll ‘a’, ‘d’ and r-phycoerythrin.

• Found on surface as well as great depths in oceans.

• Cell wall as cellulose.

• Reserve food material is floridean starch.

• e.g., Polysiphonia, Porphyra, Gelidium.

Discussion