Because of the fission process that consumes the fuels, the old fuel rods must be changed periodically to fresh ones (this period is called a cycle). However, only a part of the assemblies (typically one-third) are removed since the fuel depletion is not spatially uniform.
In fertilization, the sperm and egg both contain one set of chromosomes. the father (sperm) and one from the mother (egg). In SCNT, the egg cell's single set of chromosomes is removed. chromosomes. come from the somatic cell.
4. Therapeutic cloning: growth of somatic stem cells in an embryo that has been produced by fertilization in vitro and modified by replacement of its nuclear material with DNA from a host with deficient or diseased tissue (for example, heart, liver, pancreas).