Search results
Results from the WOW.Com Content Network
Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis.
One theory on how meiosis arose is that it evolved from transformation. [2] According to this view, the evolutionary transition from prokaryotic sex to eukaryotic sex was continuous. Transformation, like meiosis, is a complex process requiring the function of numerous gene products.
The sperm plasma then fuses with the egg's plasma membrane and their nuclei fuse, triggering the sperm head to disconnect from its flagellum as the egg travels down the fallopian tube to reach the uterus. In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, in vitro.
Animals have life cycles with a single diploid multicellular phase that produces haploid gametes directly by meiosis. Male gametes are called sperm, and female gametes are called eggs or ova. In animals, fertilization of the ovum by a sperm results in the formation of a diploid zygote that develops by repeated mitotic divisions into a diploid ...
The sperm and the ovum are known as the gametes (each containing half the genetic information of the parent, created through meiosis). [citation needed] The sperm (being one of approximately 250 million sperm in a typical ejaculation) travels through the vagina and cervix into the uterus or fallopian tubes. Only 1 in 14 million of the ...
Animals, including mammals, produce gametes (sperm and egg) through meiosis in gonads (testicles in males and ovaries in females). Sperm are produced by the process of spermatogenesis and eggs are produced by oogenesis. These processes are outlined in the article gametogenesis.
Animals, including mammals, produce gametes (sperm and egg) by means of meiosis in gonads (testicles in males and ovaries in females). Sperm are produced by spermatogenesis and eggs are produced by oogenesis .
Typically in a female mammal, meiosis starts with one diploid cell and becomes one haploid ovum and typically two polar bodies, however one may later divide to form a third polar body. [4] In a male, meiosis starts with one diploid cell and ends with four sperm. [5] In mammals, the female pronucleus starts in the center of the egg before ...