Q1. The answer is 53 chromosomes
Zebra has 44 diploid chromosomes (2n = 44). Zebra's gametes are haploid, so they will have 22 chromosomes (n = 22).
Donkey has 62 diploid chromosomes (2n = 62). Zebra's gametes are haploid, so they will have 31 chromosomes (n = 31).
After fusion of zebra's gamete (n = 22) and donkey's gamete (n = 31), the zonkey's zygote will have 22 + 31 = 53 chromosomes
Q2 and Q3. In the meiosis, the number of chromosomes is reduced by half. Since zonkey has 53 chromosomes, after meiosis it should have 53/2 chromosomes, which is not the whole number. This is the reason why they cannot produce normal gametes that will result, after the fusion, in the production of normal diploid zygote