Biological means relating to living things and the processes of life. When scientists study the biological world, they're examining plants, animals, bacteria, humans, and all other organisms, exploring how they grow, function, reproduce, and interact with their environments.

Your body runs on biological processes every second: your heart pumps blood, your lungs take in oxygen, your cells convert food into energy, and your brain sends signals through your nerves. These are all biological functions that keep you alive. A biologist is a scientist who studies these processes, whether they're researching how dolphins communicate, how trees produce oxygen, or how diseases spread.

The word appears in many contexts. Your biological parents are the ones whose genes you inherited, as opposed to adoptive parents. A biological clock refers to natural rhythms in living things, like how you feel sleepy at night or how bears hibernate in winter. Biological diversity (or biodiversity) describes the variety of different species living in an area.

When farmers use biological pest control, they're using living things like ladybugs to eat aphids instead of using chemical sprays.