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Chromosomes in the cell nucleus

exists in a cell's nucleus within structures called . Each section of a chromosome that contains the code for the production of a particular protein is called a .

Diagram showing a chromosome and its DNA

Each chromosome is made from a single molecule of DNA, but when a cell is ready to divide, the DNA copies itself, then coils and condenses to form the chromosomes that we see in .

Chromosomes carry genetic information in a molecule called DNA.

Each human body cell contains 46 chromosomes. These can be arranged into 23 pairs.

Each chromosome in a pair carries the same genes. One chromosome was inherited from the organism's mother, and is known as the chromosome, and the other chromsome in the pair was inherited from the organism's father, and is known as the chromosome.

The 23rd pair is the sex chromosomes. In females, the two chromosomes are identical in shape. There are two X chromosomes. Females are referred to as XX.

In males, one of the sex chromosomes is a different shape. There is an X and also a Y chromosome. Males are referred to as XY.

All eggs are X. Approximately half of sperm are X and the other are Y.

Diagram showing strands of chromosomes and maternal/paternal inheritance
Diagram showing how male and female chromosomes form