The question asks to identify the specific type of sexual reproduction in algae characterized by the fusion of a large, non-motile female gamete and a smaller, motile male gamete. We need to recall the definitions of different types of gamete fusion (syngamy) found in algae and other organisms.
C) Oogamy — This term specifically describes the type of sexual reproduction where there is a distinct difference between the gametes: a large, non-motile female gamete (egg) and a smaller, motile male gamete (sperm). This is a highly evolved form of sexual reproduction found in many advanced algae and all higher plants and animals.
The question asks to identify an alga known for its high protein content, making it suitable as a food supplement, even for space travelers. This points to a specific type of microalga recognized for its nutritional value.
A) Chlorella — Chlorella is a genus of single-celled green algae, famous for its exceptional nutritional value. It contains a high percentage of protein (around 50-60% of its dry weight), along with essential amino acids, vitamins (including B12), minerals, and chlorophyll. Due to this rich composition, it is widely used as a dietary supplement and has been investigated for its potential as a food source in closed ecological systems, such as those for long-duration space missions. Its ability to photosynthesize efficiently and provide a complete nutritional profile makes it an ideal candidate for space travel food supplements.
The question asks to identify the class of algae from which the commercial product 'algin' is obtained. This requires knowledge of the different classes of algae and the specific products derived from them.
Correct Option: B) Phaeophyceae — Algin is a phycocolloid extracted from the cell walls of brown algae, which belong to the class Phaeophyceae. Examples include Laminaria, Sargassum, and Macrocystis.
This question tests knowledge about the storage carbohydrates found in different groups of organisms, specifically focusing on the structural similarity of Floridean starch found in red algae to other common polysaccharides.
Correct Option: B) Amylopectin and glycogen
Floridean starch is a branched polymer of glucose, structurally very similar to amylopectin (the branched component of plant starch) and glycogen (the storage polysaccharide in animals and fungi). All three are composed of glucose units linked by \(\alpha\)-1,4 glycosidic bonds in the main chain and \(\alpha\)-1,6 glycosidic bonds at branch points.
This question asks about the form of stored food in Phaeophyceae, which are commonly known as brown algae. To answer this, one needs to recall the characteristic storage products of different algal groups.
Correct Option: A) Laminarin or mannitol
Phaeophyceae (brown algae) store their food as laminarin, a polysaccharide, and mannitol, a sugar alcohol. These are characteristic storage products for this group.
The question asks to identify the pigment responsible for the characteristic red color of red algae. This requires knowledge of the different types of photosynthetic pigments found in various algal groups.
Correct Option: D) r-phycoerythrin is a red pigment belonging to the phycobiliprotein family, which is abundantly found in red algae (Rhodophyta) and is primarily responsible for their red coloration.