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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 differentiates into the cells of an embryo. There are approximately 220 types of somatic cell in the ...
The typical normal human fetal cell will divide between 50 and 70 times before experiencing senescence. As the cell divides, the telomeres on the ends of chromosomes shorten. The Hayflick limit is the limit on cell replication imposed by the shortening of telomeres with each division. This end stage is known as cellular senescence.
In somatic cell nuclear transfer ("SCNT"), the nucleus of a somatic cell is taken from a donor and transplanted into a host egg cell, which had its own genetic material removed previously, making it an enucleated egg. After the donor somatic cell genetic material is transferred into the host oocyte with a micropipette, the somatic cell genetic ...
In cellular biology, the term somatic is derived from the French somatique which comes from Ancient Greek σωματικός (sōmatikós, “bodily”), and σῶμα (sôma, “body”.) [1] [2] is often used to refer to the cells of the body, in contrast to the reproductive cells, which usually give rise to the egg or sperm (or other gametes in other organisms).
What is left is a somatic cell and an enucleated egg cell. These are then fused by inserting the somatic cell into the 'empty' ovum. [7] After being inserted into the egg, the somatic cell nucleus is reprogrammed by its host egg cell. The ovum, now containing the somatic cell's nucleus, is stimulated with a shock and will begin to divide.
A key point to remember is that cloning is achieved when the oocyte maintains its normal functions and instead of using sperm and egg genomes to replicate, the donor's somatic cell nucleus is inserted into the oocyte. [17] The oocyte will react to the somatic cell nucleus, the same way it would to a sperm cell's nucleus. [17]
This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. [5] The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a double helix of two complementary strands.
In addition, stem cell are undifferentiated cells which can develop into a specialized cell and are the earliest type of cell in a cell lineage. [2] Due to the differentiation in function, somatic cells are found only in multicellular organisms, as in unicellular ones the purposes of somatic and germ cells are consolidated in one cell.