Diatoms & Diatomaceous Earth — NEET Biology
✅ Asked in NEET 2018This group includes diatoms and golden algae (desmids). They are found in fresh water as well as in marine environments. They are microscopic and float passively in water currents (plankton). Most of them are photosynthetic. In diatoms the cell walls form two thin overlapping shells, which fit together as in a soap box. The walls are embedded with silica and thus the walls are indestructible. Thus, diatoms have left behind large amount of cell wall deposits in their habitat; this accumulation over billions of years is referred to as 'diatomaceous earth'. Being gritty this soil is used in polishing, filtration of oils and syrups. Diatoms are the chief 'producers' in the oceans.
NTA tests diatoms as the primary producers in marine ecosystems with unique silica-embedded cell walls. Students often confuse diatoms with other algae or forget that their indestructible walls accumulate as diatomaceous earth over geological time. Key trap: mistaking diatoms for dinoflagellates or thinking their cell walls are made of cellulose—they're actually silica-based, making them gritty and useful for polishing and filtration. Remember: diatoms are unicellular, photosynthetic plankton found in both fresh and marine water, and their massive fossil deposits (diatomaceous earth) are a signature feature tested for understanding ecological and commercial significance.
This paragraph was tested 2 times in NEET.
Which of the following organisms are known as chief producers in the oceans? NEET 2018
Select the wrong statement. NEET 2016
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.