Question

Write a detail note on a unicellular algae that you have studied. (5 Marks)

Answer 1

(1 Mark)
Chlamydomonas:
Chlamydomonas is a simple, unicellular, motile fresh water algae. (0.5 Marks)

• They are oval, spherical or pyriform in shape. The pyriform (pear shape) is a common one found in ponds, ditches and water tanks. (0.5 Marks)
• They have a narrow anterior end and a broad posterior end. (0.5 Marks)
• The cell is surrounded by a thin and firm cell wall made of cellulose. (0.5 Marks)
• The cytoplasm is seen in between the cell membrane and the chloroplast. The cell contains large dark nucleus lying inside the cavity of the cup shaped chloroplast. (0.5 Marks)
• The anterior part of the cell bears two flagella which helps in locomotion. (0.5 Marks)
• Two contractile vacuoles are seen at the base of each flagellum. The anterior side of the chloroplast contains a tiny red coloured eyespot. (0.5 Marks)
• Chlamydomonas exhibits sexual and asexual modes of reproduction. (0.5 Marks)