Question

Which of the following are the characteristics of phaeophyceae?
(i) Possess chlorophyll a, c, carotenoids and xanthophylls.
(ii) Food stored is in the form of laminarin and mannitol.
(iii) Asexual reproduction by biflagellate zoospores that have two equal apically attached flagella.
(iv) Cell wall has cellulose and algin.
(v) Sexual reproduction is oogamous only.
(vi) Gametes have two laterally attached flagella.

• A. i, iii, iv, v
• B. ii, iii, v, vi
• C. i, ii, iv, vi
• D. i, ii, v

Answer 1

Answer: (C)

The members of phaeophyceae or brown algae are found primarily in marine habitats. They show great variation in size and form. They possess chlorophyll a, c, carotenoids and xanthophylls. They vary in colour from olive green to various shades of brown depending upon the amount of the xanthophyll pigment, fucoxanthin present in them. Food is stored as complex carbohydrates, which may be in the form of laminarin or mannitol. The vegetative cells have a cellulosic wall usually covered on the outside by a gelatinous coating of algin. Vegetative reproduction takes place by fragmentation. Asexual reproduction in most brown algae is by biflagellate zoospores that are pear-shaped and have two unequal laterally attached flagella. Sexual reproduction may be isogamous, anisogamous or oogamous. Union of gametes may take place in water or within the oogonium (oogamous species). The gametes are pyriform (pear-shaped) and bear two laterally attached flagella.