When particles spread out it is called diffusion.
The given section of DNA is known as a gene.
Explanation:
The basic physical as well as fundamental unit of heredity is known as gene. Genes are built with DNA. According to Human Genome Project human have estimated between 20000 to 25000 genes. In Every person two copies of each gene are present which is carried from parent.
In most of the genes are common almost every people but less than 1% of genes are different between people. The role of gene is to determine the trait- how we look and also other stuff about us.
