Why does the head sperm cell contains enzymes vital to fertilization

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

Most crimes involve some evidence relating to the human body; for that reason, what related science is frequently used in forensic investigations? a)psychiatry b)physics c)botany d)biology

What are the fixed alleles in the human species? o a. the alleles that are on the most chromosomes b. the alleles that change most often 000 c. the alleles that no one has d. the alleles that everyone has