Simplifying things greatly (as this guide aims to do, mostly), quantum dots are incredibly small particles. They range between 2 to 10 nanometers in diameter, which is equivalent to 50 atoms. Yes, atoms. You can't measure these things using your old school shatter proof ruler. It's this small size that gives quantum dots the unique properties to improve our tech.
If it is a human zygote with no mutations, then it will contain 46 chromosomes. Each parent gives the zygote 23 chromosomes. All human gametes without mutations contain 23 and when joined during fertilization they form a zygote with 46 chromosomes. However, chromosome number varies by species, for example a normal pigeon zygote would have 80 chromosomes.
For example, diploid human cells contain 23 pairs of chromosomes (46 total), half of maternal origin and half of paternal origin. Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes.