Cells are the basic unit of life. They make up all living things, including plants and animals. Plant and animal cells contain similar structures like the nucleus, mitochondria, and cytoplasm, which perform similar functions like producing energy and controlling processes. However, plant and animal cells also contain some unique structures that allow them to perform specialized functions essential to their type of cell. Cells carry out important processes like diffusion, osmosis, and active and passive transport to maintain functions.