Rhodophyceae or Red Algae MCQ - Practice Questions with Answers

• The members of Rhodophyceae are commonly called red algae. Eg. Polysiphonia, Porphyra, Gelidium etc. 
• They mostly live in warmer marine waters.
• The thallus is usually multicellular and some even have complex organization.
• Cell wall contains cellulose and pectin along with phycocolloids and carrageenan.
• They have chlorophyll a and d. 
• The red colour is due to R-Phycoerythrin. 
• It also has a phycocyanin. 
• Due to the presence of Phycoerythrin they can grow in deep waters where other algae cannot grow.
• The reserve food is Floridean Starch which is similar to amylopectin and glycogen. 

Reproduction in Rhodophyceae:

• Vegetative reproduction takes place by fragmentation. 
• Asexual reproduction by non-flagellate spores called as archaeospores, neutral spores and mono spores.
• Sexual reproduction takes place by oogamy. 
• The female sex organ is carpogonium with a single egg cell and male sex organ spermatangium with non-motile male gametes called as spermatia. 
• This algal group shows post fertilisation changes also. 

Economic importance of Rhodophyceae:

• Red algae (Rhodophyceae) used in preparing solid food media in laboratories and as a thickening and binding agent in food industries.
• Agar-agar is obtained commercially from Gelidium and Gracilaria.
• Red algae (Rhodophyceae) used in pharmaceutical, textile, leather and cosmetic industries obtained from Chondrus crispus.