Infant development experts say that teething usually starts when your baby is around four months old, and continues until he or she is about two years old, at which time you get a reprieve until about five years old when the baby teeth start being replaced by grown-up teeth.
Quick Answer. Meiosis contributes to genetic variation by creating new groups of genes, according to the University of Miami Miller School of Medicine. The new groups are created when chromosomes passed down from a mother and father share instructions encoded into genes.
Specifically, meiosis creates new combinations of genetic material in each of the four daughter cells. These new combinations result from the exchange of DNA between paired chromosomes. Such exchange means that the gametes produced through meiosis exhibit an amazing range of genetic variation.