Question: Which of the following best describes how genetically modified mice are produced? Plasmid DNA is …

Which of the following best describes how genetically modified
mice are produced?

Plasmid DNA is injected into early blastoderms, producing
genetically modified offspring.

Blastoderms are removed from females, injected with plasmid DNA,
and reintroduced into the pregnant female mouse, producing
genetically modified offspring.

Blastoderms are removed from pregnant female mice and injected
with genetically modified embryonic stem cells (ES cells).
These genetically chimeric
blastoderms are then reintroduced into the pregnant female mouse.
Any sperm or eggs produced from the genetically modified ES cells
will go on to produce a transformant offspring, which can be
identified based on a scorable selectable marker.

Blastoderms are removed from
pregnant female mice and injected with genetically modified
embryonic stem cells (ES cells). These genetically chimeric blastoderms are then
reintroduced into the pregnant female mouse, and and the resulting
offspring are screened for transformant animals based on a scorable
selectable marker.

Plasmid DNA is injected into
early blastoderms, producing genetically modified
offspring.These genetically
chimeric blastoderms are then reintroduced into the pregnant female
mouse. Any sperm or eggs produced from the genetically modified ES
cells will go on to produce a transformant offspring, which can be
identified based on a scorable selectable marker.