Genome and DNA

• Genes, the basic unit of inheritance, are passed down through generations in a predictable manner.
• Each gene stores information in the form of deoxyribonucleic acid (DNA).
• The genome is the sum total of the information, DNA, and genetic material in a living organism.

The Genome (DNA)

• The average adult human body is composed of approximately 50 trillion cells.
• Most DNA is located in the nuclei of cells, with a smaller amount in the mitochondria and plastids.
• The average human cell is around 20µm in diameter and most of a cell's DNA is stored in its nucleus, which is around 2-10µm in diameter.
• Each nucleated human cell manages to pack around 3m (10 feet) of DNA.
• To make this possible, DNA is neatly wrapped around histone proteins that function like a spool or bobbin.
• DNA and histone proteins form a material called chromatin, which is visible in the cell nucleus in the form of microscopic granules.
• At the onset of cell division, the DNA winds up tighter and folds into coils.
• This tightly wound DNA is denser and thicker, and appears in the nucleus in the form of thread-like structures called chromosomes.

Understand the basics of genome and DNA. Learn about DNA packaging, chromatin, and its important role. Explore how DNA is neatly wrapped around histone proteins.