Question

Write short note on chlorophyceae

Answer 1

it is green algae ,it contains chlorophyll a,b ,it contain starch ,it has cellulose

Answer 2

Members of Chlorophyceae grow mostly in fresh water, a few in brackish and saline water and a few are terrestrial.

2. They show wide range of variations in their thallus structures like unicellular motile (Chlamydomonas) and non-motile (Chlorella), coenobium (Volvox), palmelloid (Tetraspora), dendroid (Ecballocystis), fila­mentous branched (Cladophora) and unbranched (Spirogyra), heterotrichous (Coleochaete), siphonaceous (Vaucheria) and parenchymatous (Ulva).

3. Flagella are 1-many, equal in size and inserted either apically or sub-apically. The flagella show typical 9+2 arrangement when viewed under E.M.

4. The cells are eukaryotic in nature. Usually there is only one nucleus in each cell, but in Siphonales and Cladophorales many nuclei are present in their coenocytic body. Normally the number of nucleolus is one per nucleus, but several nucleoli are present in the members of Conjugales.

5. The cell wall is mainly made up of cellulose, which comprised of hydroxyproline glyco­sides or xylans and mannans. In Chara the cell wall is encrusted with calcium and magnesium carbonate.

6. Inner to the cell wall, semipermeable cell membrane is present which encircles the protoplast. The cytoplasm contains many small vacuoles which pushes the nucleus with cytoplasm towards the periphery and called primordial utricle.

7. The flagellate cells have eye-spot or stigma in the anterior portion, which remain inser­ted at one side of the chloroplast.

8. The pigments are located in the chloro­plast. Chkiroplast generally contains pyrenoid(s).