Can a sperm cell contain maternal chromosomes?
Sperm cells carry only paternal DNA from the father. The maternal DNA is that which is inside the egg cell. Actually, the maternal genome isn’t even present until after the sperm cell penetrates the egg and the act of fertilization triggers the formation of the second polar body which, when dispersed at the surface of the egg’s membrane, does the maternal haploid genome truly form. Some two hours post fertilization, paternal DNA and maternal DNA comes together to form the beginnings of a zygote genome. The zygotes’ genome really doesn’t take over embryonic and fetal development until something like 4 weeks after implantation and beginnings of organ system differentiation and maturation. Only then does new life actually exist.
