Answer:
AB, ab, Ab and aB
Explanation:
The zygote has the genotype AaBb because it was formed by the fusion of a sperm cell AB and an egg ab.
During meiosis the diploid AaBb germ cell will reduce its chromosome number by half, producing a total of 4 haploid daughter cells (the gametes, in males the sperm cells) with just one allele per gene. The genes A and B are on different chromosomes, so they assort independently, and 4 types of gametes can therefore be produced: AB, Ab, aB and ab.