It is the unit of heredity, and may be copied and passed on to the next generation. The diagram shows the relationship between the cell, its nucleus, chromosomes in the nucleus, and genes.

Each gene might have different forms, and these are called alleles. The diagram shows the relationship between the cell, its nucleus, chromosomes in the nucleus, and genes.

In addition to the nucleus, eukaryotic cells may contain several other types of organelles, which may include mitochondria, chloroplasts, the endoplasmic reticulum, the Golgi apparatus ...