4. Chromosome structure

4.1 Definitions

Genome The DNA content of a cell.
Chromosome Within the DNA genome, there are a large independent DNA fragments called chromosomes.
Chromatid One of the 2 nucleofilaments that make up the chromosome. Before DNA replication, the chromosome is monochromatidian. After DNA replication , the 2 DNA daughter molecules form two chromatids (called sister chromatids). The chromosome is said to be bi-chromatidian.
Prokaryotic cell A bacterial-type cell without a nucleus. DNA is loosely distributed in the cytoplasm.
Eukaryotic cell An animal or vegetal cell with a nucleus containing DNA.
Haploid genome Only one single copy of a chromosome is present in each cell.
Diploid genome Two copies of each chromosome are present in each cell (in humans, one copy is derived from the father, and one copy from the mother).