Ver el código de «Department Cf Energy Mines And Resources»

<br>In cellular biology, a somatic cell (from Ancient Greek σῶμα (sôma) 'body'), or vegetal cell, is any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Somatic cells compose the body of an organism and divide through mitosis. In contrast, gametes derive from meiosis within the germ cells of the germline and they fuse during sexual reproduction. Stem cells also can divide through mitosis, but are different from somatic in that they differentiate into diverse specialized cell types. In mammals, somatic cells make up all the internal organs, skin, bones, blood and connective tissue, while mammalian germ cells give rise to spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, which divides and [https://www.ft.com/search?q=differentiates differentiates] into the cells of an embryo. There are approximately 220 types of somatic cell in the human body. Theoretically, these cells are not germ cells (the source of gametes); they transmit their mutations, to their cellular descendants (if they have any), but not to the organism's descendants.<br><br><br><br>However, in sponges,  [http://huaang6688.gnway.cc:3000/indiracupp973/primeboosts.com3827/wiki/The+Best+Way+for+a+40+Year+Old+Male+to+Gain+Muscle+Size This product] non-differentiated somatic cells form the germ line and, in Cnidaria, differentiated somatic cells are the source of the germline. Mitotic cell division is only seen in diploid somatic cells. Only some cells like germ cells take part in reproduction. The evolution of an immortal germline producing specialized somatic cells involved the emergence of mortality, and can be viewed in its simplest version in volvocine algae. Those species with a separation between sterile somatic cells and a germline are called Weismannists. Weismannist development is relatively rare (e.g., vertebrates, arthropods, Volvox), as many species have the capacity for somatic embryogenesis (e.g., land plants, most algae, and numerous invertebrates). Like all cells, somatic cells contain DNA arranged in chromosomes. If a somatic cell contains chromosomes arranged in pairs, it is called diploid and the organism is called a diploid organism. The gametes of diploid organisms contain only single unpaired chromosomes and are called haploid.<br><br><br><br>Each pair of chromosomes comprises one chromosome inherited from the father and one inherited from the mother. In humans, somatic cells contain 46 chromosomes organized into 23 pairs. By contrast, gametes of diploid organisms contain only half as many chromosomes. In humans, this is 23 unpaired chromosomes. When two gametes (i.e. a spermatozoon and an ovum) meet during conception,  [https://foutadjallon.com/index.php/9_Scientifically_Proven_Ways_To_Build_Muscle_Fast PrimeBoosts.com] they fuse together, creating a zygote. Due to the fusion of the two gametes, a human zygote contains 46 chromosomes (i.e. 23 pairs). A large number of species have the chromosomes in their somatic cells arranged in fours ("tetraploid") or even sixes ("hexaploid"). Thus,  [https://git.minaev.su/leslicorlette4/prime-boosts-supplement5724/wiki/What-is-Muscular-Strength%2C-and-what-are-some-Exercises-you-can-Do%3F Prime Boosts Official] they can have diploid or even triploid germline cells. An example of this is the modern cultivated species of wheat, Triticum aestivum L., a hexaploid species whose somatic cells contain six copies of every chromatid. The frequency of spontaneous mutations is significantly lower in advanced male germ cells than in somatic cell types from the same individual. Female germ cells also show a mutation frequency that is lower than that in corresponding somatic cells and similar to that in male germ cells.<br><br><br><br>These findings appear to reflect employment of more effective mechanisms to limit the initial occurrence of spontaneous mutations in germ cells than in somatic cells. Such [https://www.thefreedictionary.com/mechanisms mechanisms] likely include elevated levels of DNA repair enzymes that ameliorate most potentially mutagenic DNA damages. In recent years, the technique of cloning whole organisms has been developed in mammals, allowing almost identical genetic clones of an animal to be produced. One method of doing this is called "somatic cell nuclear transfer" and involves removing the nucleus from a somatic cell, usually a skin cell. This nucleus contains all of the genetic information needed to produce the organism it was removed from. This nucleus is then injected into an ovum of the same species which has had its own genetic material removed. The ovum now no longer needs to be fertilized, because it contains the correct amount of genetic material (a diploid number of chromosomes).<br>