How many double-helical DNA molecules will be present in the sperm and egg cells of dogs that are diploid animals that contain 78 replicated chromosomes in each cell that enters meiosis/
So, sperm and egg cells of dog would have 39 chromosomes and one double helix DNA molecule is present in each chromosome comprising 39 double helical DNA molecules.
A chromosome has one DNA molecule before replication and have two DNA molecules after DNA replication.