How does density affect refraction?

Density of any substance or medium determine the amount of light that will be refracted.

Explanation:

Density of any substance or medium determine the amount of light that will be refracted.

The higher is the density of any medium, the higher will be the number of atom or molecules in a given medium and hence more obstruction will be produced for light. High density also causes high refractive index.  

The light usually bends away from the normal when light travels from a region of low to high density and light bends towards the normal when light travels from a region of high to low density

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.