Cell diagram sperm

Categories : Fertility Germ cells Reproductive system Mammal male reproductive system Semen Human male reproductive system. They are produced in flask-shaped structures containing nectar , which attract flies that transfer the spermatia to nearby hyphae for fertilization in a mechanism similar to insect pollination in flowering plants. The sperm cells have only 23 chromosomes, or half of the usual number. Nucleus - The sperm head is the part of the cell that contains the nucleus. In human females, for example, oogonia proliferate only in the fetus, enter meiosis before birth, and become arrested as oocytes in the first meiotic prophase , in which state they may remain for up to 50 years. A small middle portion of the sperm contains the mitochondria. Sperm Are Produced Continuously in Most Mammals In mammals, there are major differences in the way in which eggs are produced oogenesis and the way in which sperm are produced spermatogenesis.

Once the sperm cell comes in contact with the diffusible molecules from the egg jelly, this stimulates the cell to swim towards the eggs. There is some evidence that this binding is what triggers the acrosome to release the enzymes that allow the sperm to fuse with the egg. Read more. These projections radial spokes also play an important role of aligning the microtubules around the central pair.