In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) use of mitochondrial DNA from adult female cells of another ewe
B) replication and dedifferentiation of adult stem cells from sheep bone marrow
C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
E) isolation of stem cells from a lamb embryo and production of a zygote equivalent

Question

Quizplus · Accepted Answer

Dolly the sheep was cloned via nuclear transfer. In this process, the nucleus from an adult mammary gland cell was removed and inserted into an enucleated sheep egg cell. The reconstructed egg was then stimulated to divide and develop into an embryo, which was then implanted into a surrogate ewe to carry the pregnancy to term.

In 1997, Dolly the Sheep Was Cloned