Definition

1. Noun:
   • A microscopic, single-celled alga that lives in marine or freshwater environments, often forming colonies. Diatoms are characterized by their unique cell walls, which are made of silica (a glass-like substance) and have intricate, symmetrical patterns.

Usage

• Diatoms are a primary group of phytoplankton and are crucial to aquatic ecosystems as a major source of oxygen and a foundational part of the food web.
• The word is used as a countable noun (e.g., , ).

Examples

• Scientists study diatom fossils in sediment cores to understand past climate conditions.
• Under the microscope, the silica shell of a single diatom revealed a beautiful geometric design.
• The health of the lake can be assessed by the diversity of diatoms in its water.

Advanced Usage

• Diatomaceous earth: A soft, crumbly, porous sedimentary deposit formed from the fossilized silica cell walls of diatoms. It has various industrial uses, including as a filter aid, mild abrasive, and insecticide.
  • The pool filter uses diatomaceous earth to remove fine particles from the water.

Variants and Related Words

• Diatomaceous (adj): Of or relating to diatoms or their siliceous remains.
  • The diatomaceous sediment layer was several meters thick.
• Diatomite (n): Another term for diatomaceous earth.
  • The quarry mined diatomite for use in absorbent products.

Synonyms

• Phytoplankton (n): Microscopic aquatic plants, including diatoms, that drift in water. (This is a broader category.)
• Microalga (n): A microscopic alga. (This is a general term; not all microalgae are diatoms.)

Related Phrases and Terms

• Diatom bloom: A rapid increase in the population of diatoms in an aquatic system.
  • The diatom bloom in the spring turned the water a brownish-green color.
• Frustule (n): The scientific term for the siliceous cell wall of a diatom.
  • The frustule of each diatom species has a distinct shape and pattern.

Noun

1. microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica