18. Biotechnology

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

Bacteria use restriction enzymes to __________.

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?

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?

Which of the following is true of a codon? (A) It never codes for the same amino acid as another codon. (B) It can code for more than one amino acid. (C) It can be either in DNA or in RNA (D) It is the basic unit of protein structure

Which of the following would be considered a transgenic organism? a. a bacterium that has received genes via conjugation b. a human given a corrected human blood-clotting gene c. a fern grown in cell culture from a single fern root cell d. a rat with rabbit hemoglobin genes

Recombinant DNA techniques are used to custom-build bacteria for two main purposes: to obtain multiple copies of certain genes and to obtain useful proteins produced by certain genes. Give an example of each of these applications in medicine and agriculture.