Cells

Cells are the basic units that make up all living organisms. From tiny bacteria to large animals and plants, every living being is composed of one or more cells. Some organisms, such as bacteria, consist of a single cell, while others, like humans, are made of trillions of cells working together.

Each cell carries out essential functions, including obtaining energy, removing waste, and producing the molecules needed for life. Most cells contain genetic information stored in DNA, which provides instructions for their activities and reproduction.

Cells can have different shapes and structures depending on their role in an organism. Plant cells, for example, have a rigid outer wall and structures called chloroplasts that allow them to perform photosynthesis. Animal cells do not have these features but contain specialized parts that help them perform specific tasks.

Inside many cells, a nucleus stores genetic information, while other structures help produce energy or transport materials. Studying cells allows scientists to better understand how living organisms function and has contributed to major advances in medicine, biology, and biotechnology.