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.
Meiosis produces four haploid cells that may develop into potential gametes so that when fertilization occurs, a new individual with the full number of genes results, thereby maintaining the integrity of chromosomal number across generations while promoting genetic diversity and variability in forms in the population.