The term CELL EGG is composed of two words: OVUM (4 letters) and NEURON (6 letters). An OVUM is the scientific name for a female reproductive cell, also known as an egg cell. It is the largest cell in the human body and is responsible for the development of a new individual when fertilized by a sperm cell. A neuron is a type of cell found in the nervous system that is responsible for transmitting electrical signals throughout the body. Neurons are essential for the functioning of the brain and other organs.