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Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. [1] These cells are called spermatogonial stem cells. The mitotic division of these produces two ...
Lecithin contains dietary precursors to choline, an essential nutrient, which was formerly classified as a B vitamin (vitamin B 4). [17] [18] Lecithin is a mixture of fats that contains phospholipids, including phosphatidylcholine, and the human body can convert phosphatidylcholine into choline.
The sperm are transferred from the pollen through the pollen tube to the ovule where the egg is fertilised. In flowering plants, two sperm cells are released from the pollen tube, and a second fertilisation event occurs involving the second sperm cell and the central cell of the ovule, which is a second female gamete. [7]
The following are a few of the diseases that can occur and be present during the process. Polyspermy results from multiple sperm fertilizing an egg, leading to an offset number of chromosomes within the embryo. [35] Polyspermy, while physiologically possible in some species of vertebrates and invertebrates, is a lethal condition for the human ...
Sperm Spermiogenesis is the final stage of spermatogenesis , during which the spermatids develop into mature spermatozoa . At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus , Golgi apparatus , centriole and mitochondria ; by the end of the process, it has radically transformed into an elongated ...
Sperm cells form during the process known as spermatogenesis, which in amniotes (reptiles and mammals) takes place in the seminiferous tubules of the testicles. [3] This process involves the production of several successive sperm cell precursors, starting with spermatogonia , which differentiate into spermatocytes .
Sertoli cells function to nourish the developing sperm cells. They secrete androgen-binding protein , a binding protein which increases the concentration of testosterone. There are two types: convoluted and straight, convoluted toward the lateral side, and straight as the tubule comes medially to form ducts that will exit the testis.
In males, this process is known as spermatogenesis and occurs only after puberty in the seminiferous tubules of the testes. The immature spermatozoa or sperm are then sent to the epididymis, where they gain a tail, enabling motility. Each of the original diploid germ cells or primary spermatocytes forms four functional gametes, each forever young.