Questions Chapter 21

Chapter 21

1. Restriction enzymes used in most cloning experiments

   1. Are used to cut DNA into pieces for gene cloning 

   2. Are produced by bact bacteria cells to prevent viral infection

   3. Produce sticky ends on DNA fragments

   4. All of the above are true restriction enzymes

   5. Only A and C are true of restriction enzymes

2. DNA ligase is needed in a cloning experiment 

   1. To promote hydrogen bonding between sticky ends

   2. To covalently link the backbone of DNA strands

   3. To digest the chromosomal DNA into small pieces 

   4. To do only A and B

   5. To do only A, B, and C

3. Let’s suppose you performed the steps of gene cloning described in Figures 21.2 and 21.3. Which experiments would you conduct to confirm that a white colony really contained a recombinant vector with an insert?

   1. Pick a white bacterial colony and restreak it on plates containing X-Gal to confirm the cells really form white colonies.

   2. Pick a white bacterial colony, isolate plasmid DNA, digest the plasmid DNA with a restriction enzyme, then perform gel electrophoresis with the DNA.

   3. Pick a white bacterial and test to see if β-galactosidase is functional within the bacterial cells.

   4. Pick a white bacterial colony and retest it on ampicillin-containing plates to double-check that the cells are really ampicillin-resistant.

   5. Both C and D should be conducted.

4. Why is Taq polymerase used in PCR rather than other DNA polymerases?

   1. Taq polymerase is a synthetic enzyme that produces DNA strands at a faster rate than natural polymerases. 

   2. Taq polymerase is a heat-stable form of DNA strands that can function after exposure to the high temperature necessary for PCR.

   3. Taq polymerase is earlier to isolate than other DNA polymerases.

   4. Taq polymerase is the DNA polymerase commonly produced by most eukaryotic cells.

   5. All of the above are correct.

5. Let's suppose you want to clone a gene that has never been analyzed before by DNA sequencing. Which of the following statements is the most accurate? 

   1. Do PCR to clone the gene because it is much faster.

   2. Do PCR to clone the gene because it is very specific and gives a high yield.

   3. You can't do PCR because you can't make forward and reverse primers.

   4. Do cloning using a vector because it will give you a higher yield.

   5. Do cloning by insertion into a vector because it is easier than PCR.

6. In the CRISPR-Cas technology for editing genes, what is (are) the function(s) of sgRNA?

   1. To bind to the target Gene

   2. To bind to Cas9

   3. To cause a double-strand break in the target Gene

   4. All of the above

   5. Both A and B

7. Which of the following is not an important reason for studying the genomes of bacteria and archaea?

   1. It may provide information that helps us understand how bacteria infect other organisms.

   2. It may provide a basic understanding of cellular processes that allow us to determine the eukaryotic cellular information. 

   3. It may provide the means of understanding evolutionary processes.

   4. It will reveal the approximate number of genes that an organism has in its genome.

   5. All of the above are important reasons. 

8. The inside that helps short segments of DNA move from one chromosomal location to another is

   1. Transposase

   2. DNA polymerase

   3. Protease

   4. Restriction endonuclease

   5. DNA ligase 

9. A gene family includes 

   1. One specific Gene found in several different species.

   2. All of the genes in the same chromosome.

   3. Two or more homologous genes found in a single species.

   4. Genes that code for structural proteins 

   5. Both A and C

10. Which of the following was not a goal of the Human Genome Project?

    1. Identify all human genes

    2. Sequence the entire human genome

    3. Address the legal and ethical implications resulting from the project

    4. Develop programs to manage the information gathered from the project

    5. To be able to clone a human 

Answers: 1D 2B 3B 4B 5C 6E 7E 8A 9C 10E