Researchers are trying to make a genetically modified (GM) pig that expresses bovine (cow) growth hormone to make it grow bigger. They isolated the bovine growth hormone gene, cut it and a plasmid with the same restriction enzyme, and mixed them together. They inserted the mixture into pig zygotes, but only normal pigs, not GM pigs, grew. What did they likely do wrong?
A) They are trying to make a GM animal, which is impossible.
B) They forgot to add DNA ligase after mixing the plasmid and gene together.
C) They should have used different restriction enzymes to cut the plasmid and the gene.
D) They forgot to use PCR and make multiple copies of the growth hormone gene.

Question

Quizplus · Accepted Answer

DNA ligase is needed to join the cut bovine growth hormone gene and plasmid back together to create a recombinant plasmid. Without ligase, the gene cannot be properly inserted into the pig zygote and incorporated into the pig's genome.

Researchers Are Trying to Make a Genetically Modified (GM) Pig