Knockout Mice Are Characterized by All of the Following EXCEPT

Multiple Choice

Knockout mice are characterized by all of the following EXCEPT

A) They contain null mutations in mouse genes.
B) They are generated by homologous recombination of a gene targeting vector in embryonic stem cells.
C) The initial mice produced are chimeric.
D) The effects of the mutations are usually pleiotropic.
E) The mutations are usually lethal during the embryonic stage of development.