Why are mice used in human gene research?

One of the newest applications of cell technology is called cybrid embryos. this process involves replacing the nuclear material of an animal cell with human nuclear material. how might this process affect public policies about research by using stem cells? the same policies and concerns about the use of human embryonic stem cells would most likely apply. the embryos would most likely be treated like traditional animal embryos and regulated accordingly. the process of forming cybrid embryos would most likely be banned by government regulators. the embryos would be treated as regular cells because they are not fully human in origin.

What is the membrane that sheath of schwann cell containing cytoplasm and nucleus that encloses myelin

Pls me i need this ! each cell has genes activated depending on it's job and what kind of cell it is. it is the presence of that causes the repressor protein to fall off and unblock the gene on the lac operon. if a gene is turned on then it is being an additional circular chromosome found in some bacteria that is used in genetic engineering.