6 public questions tagged with this topic.
Diatom cell walls consist of two thin, overlapping shells embedded with silica. Their indestructible wall deposits accumulate over long periods and form diatomaceous earth.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Euglenoids Slime Moulds Protozoans
Diatoms are photosynthetic chrysophytes and are described as the chief producers in the oceans. Their silica-containing cell walls also accumulate over long periods to form diatomaceous earth.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
Diatom cell walls form two thin, overlapping shells and are embedded with silica, making them indestructible. Their accumulated cell-wall deposits form diatomaceous earth.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
The organism is a diatom, a photosynthetic chrysophyte that forms part of the plankton. Diatoms are described as the chief producers in oceans, and their accumulated silica-rich walls form diatomaceous earth.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Protista - Chrysophytes and Dinoflagellates
“Efficient resource use” for synedra excluded asterionella due to. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Habitat describes where an organism occurs; niche additionally describes how it obtains resources and affects or responds to other organisms. Distribution therefore provides evidence about a niche but is not identical to it. The remaining alternatives—“Faster reproduction”, “High predation”, “Larger size”—refer to different states, processes, or scales and therefore do not express the same causal relationship. A niche is the multidimensional set of abiotic conditions, resources, and biotic relationships under which a population can persist. The fundamental niche reflects physiological and resource limits, while the realized niche is modified by competitors, consumers, mutualists, and dispersal barriers. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 13
Chrysophytes, which include diatoms and golden algae (desmids), have unique cell walls forming two thin overlapping shells that fit together. According to NCERT, these walls are heavily embedded with silica, making them practically indestructible. Over billions of years, diatoms leave behind large amounts of these silica cell wall deposits in their habitat, which accumulates to form gritty 'diatomaceous earth', used commercially in filtration and polishing.
Ref: NCERT Class 11 Biology > Chapter 2: Biological Classification > 2.2 Kingdom Protista
