Light changes direction slightly when passing from one substance to another?

This phenomenon is known as Refraction.

Explanation:

Light waves change speed when they pass across the boundary between two substances with a different density, such as air and glass. This causes them to change direction, an effect called refraction.

At the boundary between two transparent substances:

the light slows down going into a denser substance, and the ray bends towards the normal

the light speeds up going into a less dense substance, and the ray bends away from the normal

each of the 46 original chromosomes splits into two daughter chromosomes, so there are two sets of 46 daughter chromosomes that end up in each cell. human cells have 46 chromosomes. each chromosome consists of a pair of identical chromatids attached together by a structure called a centromere.