Question

which process reduces the number of chromosomes by half?
meiosis
ketosis
fertilization

Explanation:

Meiosis is a type of cell - division that produces gametes. It involves two rounds of division and reduces the chromosome number by half. Ketosis is a metabolic state related to fat - breakdown, not chromosome number change. Fertilization combines gametes and restores the full chromosome number, not reducing it.

Answer:

meiosis