Answer: crossing over
during the process of fertilization, a sperm and egg join together to create a zygote. since a sperm had half the number of chromosomes and an egg has half the number of chromosomes, when they join together the zygote had a complete diploid set of chromosomes. the assortment of chromosomes and crossing over promotes genetic variation during the process of reproduction
The phase after ovulation (release of an egg) is called luteal phase. The stimulating follicle hormone (fsh) and luteinizing hormone (lh) are produced in the pituitary.
The FSH promotes the growth of an egg in the follicle while the LH facilitates its release from the follicle. Once the egg is released, the two hormones decrease, resulting in the rise of estrogen and progesterone.
I'm not entirely sure, but I think it is B) the pulley.
The organ that living things such as fish use to extract dissolved oxygen from water are the gills. As land animals and humans don't have gills, we can't breath underwater and take in the oxygen from that source.