Deck 14: The Future Is Here: Microorganisms and Biotechnology

Question 1

Genome analysis of bacteria has revealed:

A) that intracellular pathogens have the largest genomes of all bacteria.
B) nonfastidious bacteria have smaller genomes than fastidious bacteria.
C) that the genomes of different bacteria are remarkably similar.
D) bacteria can, at least on occasion, transfer virulence genes to each other.

Answer 1

D

Question 2

What is bioremediation?

A) the production of genetically modified foods
B) the use of recombinant microorganisms to produce pharmaceutical products
C) the production of transgenic animals
D) the sequencing and study of entire genomes
E) the use of microorganisms to degrade harmful chemicals or otherwise detoxify environmental pollutants

Answer 2

E

Question 3

What is the polymerase chain reaction? Briefly state how it works.

Answer 3

The polymerase chain reaction (PCR) is a technique used by researchers to quickly amplify a specific sequence of DNA. The DNA to be copied (the target DNA) is placed in a tube along with short DNA sequences called primers, which are complementary to the ends of the target DNA. A supply of A,G,C and T nucleotides is also added to the mixture, as is a DNA polymerase enzyme that is capable of withstanding high temperatures (Taq polymerase). The mixture is then placed in a thermocycler-a device that can be programmed to alternate among various temperatures.
In PCR there are three temperature stages. The first stage heats the DNA up to the point where it separates into single strands. In the second stage, the temperature is lowered, allowing the primers to attach to the ends of the target DNA. In the third stage, the Taq polymerase copies each of the single strands into double stranded DNA, doubling the amount of the original target DNA. The process is then repeated, usually around 30 times, doubling the amount of target DNA each time. The final result can be billions of copies of the original target DNA.

Question 4

When DNA fragments are separated by gel electrophoresis:

A) smaller fragments migrate further on the gel than larger fragments.
B) larger fragments migrate further on the gel than smaller fragments.
C) fragments that contain larger amounts of purines, relative to pyrimadines, migrate further.
D) fragments that contain many G-C pairs, relative to A-T pairs, migrate further.
E) all fragments containing genes with related functions migrate to an identical spot on the gel.

Question 5

If a gene of interest is inserted into a plasmid, and the plasmid also has a lethal gene and an antibiotic resistance gene, to later identify those plasmids:

A) the inserted gene must not disrupt either the resistance or the lethal gene.
B) the inserted gene must interrupt the resistance gene.
C) the inserted gene must interrupt the lethal gene.
D) the inserted gene must interrupt both the resistance gene and the lethal gene.

Question 6

One of the concerns about genetically modified plants is how they might affect wild plants. In what way? Why is this worrisome?

Question 7

A foreign gene is incorporated into a virus, creating a recombinant virus. The virus is now allowed to infect certain cells, with the hope that the foreign gene carried by the virus will be incorporated into the DNA of the cells. Which of the following is true?

A) The virus is the cloning vector.
B) The cells are the cloning vectors.
C) The virus is the cloning host.
D) Both "a" and "c" are correct.
E) Both "b" and "c" are correct.

Question 8

The sequencing of the human genome has shown us that:

A) the number of genes in the human genome is much smaller than previously thought.
B) the number of genes in the human genome is much larger than previously thought.
C) the number of genes in the human genome is about the same number as previously thought.
D) the DNA of humans is much different from that of even our closest nonhuman ancestors.

Question 9

Which of the following is not added to the reaction mix in the polymerase chain reaction?

A) a DNA polymerase enzyme
B) appropriate primers
C) target DNA
D) a supply of DNA nucleotides
E) a gene probe

Question 10

Southern blotting can be used to:

A) insert donor DNA into recipient DNA.
B) determine if a specific gene is present in a DNA molecule.
C) separate DNA fragments based on size.
D) make many copies of a particular gene.
E) determine the exact nucleotide sequence in a DNA molecule.

Question 11

What exactly is a DNA library? What is a genomic library?

Question 12

Which of the following is an important obstacle to the routine use of gene therapy?

A) It has proven difficult to produce recombinant viruses carrying normal copies of a particular human gene.
B) It has proven difficult to get human host cells to express foreign genes in adequate amounts.
C) It has proven difficult to identify the human genes involved in genetic disorders.
D) None of the above is currently an obstacle. Gene therapy is now routine.
E) All of the above are important obstacles.

Question 13

A restriction enzyme that recognizes relatively rare base sequences in the DNA will:

A) cleave DNA into a relatively large number of small fragments.
B) cleave DNA into a relatively small number of small fragments.
C) cleave DNA into a relatively large number of large fragments.
D) cleave DNA into a relatively small number of large fragments.