MZ twins are identical twins that share 100% of the same DNA. DZ twins share only 50% of their DNA (fraternal twins). MZ twins are always the same gender, whereas DZ twins can be the same gender or...
When sperm and egg unite, they create a zygote through fertilization. Over time, the zygote will divide into millions upon millions of cells. Each cell consists of 46 chromosomes; these cells, as a...