Organelles are specialized structures within a cell that perform specific functions. They are responsible for cellular growth, maintenance, and reproduction. Examples of organelles include the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. Each organelle has a specific role in the cell, such as DNA storage and replication, energy production, protein synthesis, and transport of molecules. Therefore, organelles are the correct answer as they are directly involved in the special functions related to cellular growth, maintenance, and reproduction.