Answer: There are 32 chromosomes in an egg produced by the horse, 31 chromosomes in a sperm produced by the donkey, and 63 total chromosomes in an offspring mule.
Step-by-step explanation:
Organisms are diploid, which means they have two copies of each gene. For example, the horse is 2n=64 and the donkey is 2n=62, because there are two sets of chromosomes in each animal.
Gametes are sex cells, which can be either an egg (in females) or sperm (in males) and they are produced through a process called Meiosis. It occurs in the gonads and it is a process of cell division in which a diploid cell (2n) undergoes two successive divisions, with the capacity to generate four haploid cells (n). So in organisms with sexual reproduction it is important because it is the mechanism by which oocytes and sperm (gametes) are produced.
During meiosis I homologous chromosomes are separated. This reductive division is responsible for the maintenance of the characteristic chromosome number of each species. In meiosis II, the sister chromatids that form each chromosome are separated and distributed among the nuclei of the daughter cells. Between these two successive stages there is no S stage (DNA replication). So the maturation of the daughter cells will give rise to the gametes.
Then, this means there are 32 chromosomes in an egg produced by the horse, because the horse has a total of 64 chromosomes. And there are 31 chromosomes in sperm produced by the donkey because it has a total of 62 chromosomes. Therefore, during fecundation, the egg fuses with the sperm (32 chromosomes + 31 chromosomes) wich will produce a zygote with a total of 63 chromosomes.