December 8, 2024 by Vijay Wardhan 1. The alga, Spirogyra are found in : Both in sea and freshwater Marine water On soil Freshwater Explanation:Spirogyra predominantly inhabits freshwater environments such as ponds, ditches, and slow-moving streams, where it forms floating mats. 2. Meiosis in Ulothrix takes place: At the time of formation of zoospores in the filament cells At the time of germination of zygote At the time of fragmentation At the time of formation of gametes Explanation:In Ulothrix, meiosis occurs during the germination of the zygote, resulting in the formation of haploid cells that will develop into new filaments. 3. The basal-cell by which an alga is attached to its substratum is known as : Holdfast Intercalary cell Hypha Rhizoid Explanation:The holdfast is a specialized basal structure used by algae to attach themselves to a substrate, providing stability in their aquatic environments. 4. Hormogonia are the vegetative reproductive structures of : Spirogyra Chlamydomonas Ulothrix Oscillatoria Explanation:Hormogonia are short, motile filaments produced by cyanobacteria like Oscillatoria, which serve as a means of vegetative reproduction. 5. The word “sea weeds” is used for: Soft-bodied algae Marine algae that have large multicellular bodies Diatoms The algae having cell walls encrusted with hard, chalky deposits Explanation:The term “sea weeds” refers to large, multicellular marine algae, such as kelps and other macroalgae, which form dense underwater forests and are important in marine ecosystems. 6. Which of the following have a prokaryotic cell? Oscillatoria Spirogyra Chlamydomonas Cladophora Explanation:Oscillatoria, a type of cyanobacteria, has prokaryotic cells, which lack a true nucleus and membrane-bound organelles, distinguishing them from eukaryotic algae like Spirogyra, Cladophora, and Chlamydomonas. 7. ‘Pond silk’ or ‘Water silk’ is the common name of : Ulothrix Spirogyra Oscillatoria Mucor Explanation:Spirogyra is commonly referred to as ‘Pond silk’ or ‘Water silk’ due to its filamentous and slimy nature, which resembles silk threads floating in water. 8. True sexuality is not found in: Blue-green algae Green algae Desmids Diatoms Explanation:True sexual reproduction involving gamete fusion is not found in blue-green algae (cyanobacteria). They primarily reproduce asexually through binary fission and fragmentation. 9. Plant body is violettish-blue or blue-green in: Trichodesmium Batrachospermum Microcystis Ectocarpus Explanation:Batrachospermum, a type of red algae, has a plant body that appears violet-blue or blue-green due to the presence of pigments such as phycobilins. 10. Richest source of protein, becoming popular throughout world and available in the Indian market also: Chlorella Spirulina Porphyra Gelidium Explanation:Spirulina is a blue-green alga known for its high protein content and nutritional value. It is widely marketed as a dietary supplement and is popular for its health benefits. Loading …
