Quick Scoop: What is plankton in biology?

Plankton are tiny organisms that drift in water and cannot swim strongly enough to fight currents. They include both plant-like forms called phytoplankton and animal-like forms called zooplankton.

Simple definition

In biology, **plankton** is a broad term for organisms that live suspended in water, moving mostly with tides and currents rather than by active swimming. They can be microscopic, but some are larger, such as certain jellyfish and crustaceans.

Main types

• Phytoplankton : plant-like plankton that make their own food using sunlight through photosynthesis. They form the base of many aquatic food webs and produce oxygen.

• Zooplankton : animal-like plankton that feed on other organisms. Many are tiny, and some are the young stages of larger sea animals.

Why they matter

Plankton are essential because they support aquatic food chains from the smallest organisms to large fish and whales. Phytoplankton also play a major role in producing oxygen and moving carbon through the ocean.

Quick example

A good everyday example is krill: they drift as plankton and are eaten by whales, fish, and other marine animals.

If you want, I can also give you a one-line school-note version or a diagram- style explanation.