To clone a high-yielding dairy cow (Cow X), agricultural scientists use somatic cell nuclear transfer (SCNT). A nucleus from a somatic cell of Cow X is transferred into an enucleated oocyte obtained from Cow Y. After activation, the resulting blastocyst is implanted into a hormonally prepared surrogate, Cow Z, which carries the pregnancy to term and gives birth to a cloned calf.
Which of the following statements regarding this cloning process or the resulting calf is not true?
The cloned calf will possess mitochondrial DNA derived entirely from Cow Y.
The surrogate mother (Cow Z) must be a genetic clone or close relative of Cow X to prevent immunological rejection of the developing blastocyst.
An electric shock is used during the reconstruction process to fuse the donor cell membrane with the oocyte and trigger the onset of mitotic divisions.
The cloned calf may not display the exact same coat pattern as Cow X due to epigenetic variation and random developmental factors such as X-chromosome inactivation.
39 exam-style questions on OCR A A Level Biology Cloning and biotechnology. Each one has a worked solution and a mark scheme showing where the marks go.