If a cell had 12 chromosomes, how many chromosomes will each daughter cells have after mitosis and cytokinesis

12 chromosomes in each cell.

Explanation:

Mitosis is a form of cellular division that produces two identical daughter cells, each having the same number of chromosomes as the parent cell.

This happens because a cell replicates it's chromosomes before dividing (this occurs in interphase), creating two sister chromatids. These chromatids then get separated in anaphase, producing two daughter cells, each with the same number of chromosomes as the parent cell.

I've attached an image which should hopefully explain how this happens. :)

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.