Afruit fly has four pairs of chromosomes. the zygote formed by the sperm and the egg of fruit flies will have chromosomes.

A fruit fly has four pairs of chromosomes. The zygote formed by the sperm and the egg of fruit flies will have four pairs of chromosomes (8 chromosomes).

Explanation:

A fruit fly has four pairs of chromosomes in a somatic cell, in a somatic cell the number of chromosomes is a diploid number (2n) in this case is 4 pairs or eight chromosomes, in a gamete is haploid number four chromosomes that is half. The chromosomes number must remain the same from one generation to its offspring. During sexual reproduction in a fruit fly, a sperm cell (4 chromosomes) combines with an ovum (4 chromosomes) forming a zygote with four pairs of chromosomes or eight chromosomes.  

the question isn't complete here so i can't right an answer '_'

yes, because even though a theory has a  lot of evidence to support it, it is not always true