Which of the following enzymes could seal a nick in one strand of a double-stranded DNA molecule by creating a sugar-phosphate bond between the adjacent, unjoined nucleotides?

Gene cloning is crucial to any application involving one gene because __________.

Bacteria use restriction enzymes to __________.

The efficiency of cloning, and the ability to generate healthy cloned animals, has been largely hampered by the difficulty of __________.

In genetic engineering, the highly active plasmid from Agrobacterium tumefaciens is used to __________.

A molecular biologist used a retroviral vector to introduce a gene coding for a certain human enzyme into mouse cells. One cell line was isolated that was able to make the human enzyme, but it had lost the ability to express an endogenous, normally expressed gene in the process. What is the best explanation for these results?

In DNA technology, the term vector can refer toa. the enzyme that cuts DNA into restriction fragments.b. the sticky end of a DNA fragment.c. a SNP marker.d. a plasmid used to transfer DNA into a living cell.