A plastid is a type of organelle found in the cells of plants and some algae. These structures are essential for various functions, including photosynthesis, storage of starches, and the synthesis of fatty acids. The most well-known plastid is the chloroplast, which contains the green pigment chlorophyll and is responsible for capturing sunlight to produce energy. Plastids can change their form and function based on the needs of the cell. For example, chromoplasts are plastids that contain pigments responsible for the colors of fruits and flowers, while amyloplasts store starch. This versatility allows plastids to play a crucial role in plant growth and development.