Phaeophyceae or Brown Algae MCQ - Practice Questions with Answers

• The members of Phaeophyceae are commonly called as Brown algae. Ex: Ectocarpus, Dictyota, Laminaria, Sargassum, Fucus
• These are mostly found in Marine habitats. 
• They are large sized and also known as Kelps (Laminaria, Macrocystis). 
• Some forms are filamentous as in Ectocarpus.
• Members of this group are olive green to brown in colour 
• Major pigments present are chlorophyll a, c, carotenoids and xanthophylls (fucoxanthin).
• The food is stored in the form of complex carbohydrates such as mannitol and laminarin.
• The cell wall has cellulose covered by gelatinous substance Algin. Algins are component of phycocolloids.
• The plant body consists of the holdfast, a short stipe and elaborate photosynthetic frond.

Reproduction in Phaeophyceae:

• Vegetative reproduction takes place by fragmentation.
• Asexual reproduction is by Zoospore formation. These are pear-shaped and have two unequal lateral flagella. These flagella are tinsel and whiplash type.
• Sexual reproduction is by isogamy, anisogamy and oogamy. 
• Fertilisation takes place either outside or inside the oogonium. 
• The male gametes are smaller and resemble the zoospores with two lateral flagella and pyriform shape.
• Fucus and Laminaria are a rich source of iodine.
• Durvillea has anti-worm properties.