Showing results for "alga"

• singular of algae.

alga

American  

[al-guh] / ˈæl gə /

noun

• algae,
  plural
• algas
  plural

1. any organism belonging to one of the numerous groups of algae.

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alga Scientific  

/ ăl′gə /

• algae
  plural

1. Any of various green, red, or brown organisms that grow mostly in water, ranging in size from single cells to large spreading seaweeds. Like plants, algae manufacture their own food through photosynthesis and release large amounts of oxygen into the atmosphere. They also fix large amounts of carbon, which would otherwise exist in the atmosphere as carbon dioxide. Algae form a major component of marine plankton and are often visible as pond scum and blooms in tidal pools. Land species mostly live in moist soil and on tree trunks or rocks. Some species live in extreme environments, such as deserts, hot springs, and glaciers. Although they were once classified as plants, the algae are now considered to be protists, with the exception of the cyanobacteria, formerly called blue-green algae. The algae do not form a distinct phylogenetic group, but the word alga serves as a convenient catch-all term for various photosynthetic protist phyla, including the green algae, brown algae, and red algae.

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Other Word Forms

Derived Forms

• alga-like
  adjective
• algal
  adjective
• antialgal
  adjective
• non-algal
  adjective

Inflected Forms

Nouns

• algae
  plural
• algas
  plural

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Example Sentences

See Examples For:

alga algae

You may never have heard of this single-celled alga, but sailors and fishermen know its effect very well: the P. lunula algae are the organisms that occasionally make the see glow blue.

From Science Daily ● Nov. 18, 2024

Blue-green algae is not actually an alga but rather a type of bacteria called cyanobacteria.

From BBC ● Jul. 10, 2023

In the case of Gracilaria, however, things are more complicated: The female alga doesn’t release its egg cells, but keeps them inside funnel-shaped filaments.

From Science Magazine ● Jul. 27, 2022

Giant kelp is the common name for Macrocystis pyrifera, a species of alga that grows into lush underwater forests along the coast of the northeastern Pacific Ocean, from Baja California north to southeastern Alaska.

From Scientific American ● Jul. 21, 2022

She is curious; she wants to know the difference between an alga and a lichen, a Diplodon char- ruanus and a Diplodon delodontus.

From "All the Light We Cannot See" by Anthony Doerr

Then about 1.25 billion years ago, one of these photosynthesizing bacteria partnered with another one-celled organism to create green algae, one lineage of which became the ancestor of all plants.

From The Wall Street Journal ● Oct. 16, 2026

The key to the success of the method -- which the team informally dubbed "helping hands" -- is the transfer of healthy photosynthetic algae, also known as symbionts, from which corals derive their color.

From Barron's ● Oct. 14, 2026

During droughts, algae blooms have turned waterways bright green, posing health threats for people and animals.

From Los Angeles Times ● Oct. 9, 2026

Familiar examples include amoebas, various algae, and diatoms, which are microscopic organisms often found in aquatic environments.

From Science Daily ● Oct. 8, 2026

I find a large one and heft it up, green and slick with algae.

From "The Cruel Prince" by Holly Black

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