4. Dogs have 78 chromosomes in their diploid cells (2n), they carry two copies of each chromosome.
The gametes (sperm cells and eggs) are haploid cells (n), which means that they carry only one copy of each chromosome. So the number of chromosomes carried by the gametes is half the number of chromosomes in other cells of the organism:
There are 39 chromosomes in the sperm cells of the german shepherd.
5. Gametes carry only one copy of each chromosome to assure that the offspring will inherit one copy from each parent and therefore have a different genetic structure. This facilitates genetic diversity within the individuals of the same population.