What would happen if two daughter cells of an organism (plants, animals) did not have identical chromosomes after division?Cell division
It depends on what cell is dividing and why. If the chromosomes are divided unequally during mitosis, one daughter cell will have trisomy, meaning that it has three copies of one of the chromosomes instead of the usual two, and the other will be missing a chromosome. The general term for this imbalance of chromosome numbers is aneuploidy. In the case of formation of a red blood cell, which has no nucleus at maturity, this is probably unimportant. Similarly a cell with a very short life span, such as an epithelial cell, would probably not be affected much.
If aneuploidy occurs during the formation of egg or sperm cells or very early in embryonic development, it can create very serious consequences. In humans aneuploidy underlies a number of serious medical conditions such as Down syndrome and Turner syndrome.