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.