What is an organelle?

An organelle is defined as a specialized structure within cells that performs distinct functions necessary for the cell's life. Examples of organelles include the mitochondria, which generate energy, the nucleus that houses genetic material, and the endoplasmic reticulum involved in protein and lipid synthesis. Each organelle has a specific role, contributing to the overall functioning of the cell, making it essential for maintaining cellular health and efficiency.

The other options describe different biological concepts. For example, the fluid that fills the cell is referred to as cytoplasm, which helps to support organelles and facilitate the movement of materials within the cell. Genetic material typically refers to DNA or RNA, which carry the instructions for an organism's development, functioning, and reproduction but are not themselves organelles. Lastly, the smallest unit of life is a cell, not an organelle, although organelles are components of cells. Understanding the definition of an organelle helps clarify the organization and functionality of cells within living organisms.