4. The diagram below shows the procedures scientists use to clone a frog from the nucleus of another frog's skin cell.
Skin cells in
culture dish
Nucleus in pipet
Inject nucleus
into egg
Tadpole
Young
embryo
Adult frog
Untertilized e99
mo
Destroy nucleus
by irradiation
The procedure is evidence that
A. The nucleus of a skin cell protects the frog.
B. Only skin cells can be used to clone a frog.
C. The skin cells are the reproductive cells in frogs.
D. The nuclei of the skin cells of the frog contain all the DNA needed to clone the
frog.