plankton

Everyday

1. Plankton are tiny plants and animals that drift in the sea and in lakes, carried by the water; most are too small to see without a microscope. tree →
2. Plant plankton (phytoplankton) make food from sunlight and produce a large share of the oxygen we breathe; animal plankton (zooplankton) include tiny shrimps and baby fish. tree →

In the lessons

In science lessons plankton come at the start of ocean food chains: plankton are eaten by small fish and krill, which are eaten by bigger fish, seals and penguins — and the biggest animal of all, the blue whale, eats mostly tiny krill. In environment lessons pupils learn that warming and polluted seas harm plankton. In a famous cartoon, Plankton is a tiny villain.

Examples

• Plankton float in the ocean. tree →
• Many whales feed on tiny plankton and krill. tree →
• Plankton are at the bottom of the ocean food chain. tree →
• Phytoplankton make oxygen from sunlight. tree →
• We looked at plankton under the microscope. tree →
• The sea glowed at night because of special plankton. tree →
• Small fish eat plankton, and bigger fish eat the small fish. tree →

Note

Uncountable in everyday use: «plankton», not «a plankton»; it can take a plural verb («plankton are») or singular («plankton is»). Plankton are not one species but many tiny living things. The word comes from Greek for «drifting».