Final answer:
The zygote will contain 100 chromosomes after the fusion of two gametes, each with 50 chromosomes.
Step-by-step explanation:
When two gametes, each containing 50 chromosomes, fuse during fertilization, the resulting zygote will contain 100 chromosomes. Gametes are haploid cells, meaning they carry just one set of chromosomes. During fertilization, the haploid sperm and haploid egg combine to form a diploid zygote, which has two sets of chromosomes -- one set from each parent. In the special case presented in the question, if each gamete carries 50 chromosomes instead of the typical 23 seen in humans, then the zygote would indeed have 100 chromosomes.