BIOL 1107K Chapter 20

During which step in the PCR cycle are nucleotides used? a. All of these steps. b. Extension. c. Denaturation. d. Annealing.

b. Extension.

Gel electrophoresis separates DNA fragments on the basis of what characteristic? a. mutations b. length c. charge d. restriction sites e. sequence

b. length

In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel. a. acidic ... basic b. negative ... positive c. basic ... acidic d. long ... short e. positive ... negative

b. negative ... positive

_____________________ _______ technology involves combining DNA from different sources into a single molecule, such as inserting a gene from one species into a plasmid from another.

Recombinant DNA

True or false? The Taq enzyme is a type of DNA polymerase that allows researchers to separate the DNA strands during the annealing step of the PCR cycle without destroying the polymerase.

False. *Note* Taq polymerase is derived from a species of bacteria living in hot springs, which makes it stable at the high temperature required for the denaturation step of PCR.

_________ is a method of DNA amplification.

PCR (polymerase chain reaction)

True or false? Comparison of the sequences of the same gene across species can give some insight into the existence of a common ancestor with that gene.

True

True or false? The shorter the DNA molecule, the farther it moves.

True

What is the polymerase chain reaction (PCR)? a. A method to amplify a fragment of DNA. b. A method to join two fragments of DNA together. c. A method to propagate a gene in bacteria. d. A method to determine the sequence of bases in a gene.

a. A method to amplify a fragment of DNA.

During which step do primers form hydrogen bonds with the single-stranded DNA template? a. Annealing. b. All of these steps. c. Extension. d. Denaturation.

a. Annealing.

During which step in the PCR cycle do primers form bonds with a single-stranded template? a. Annealing. b. All of these steps. c. Extension. d. Denaturation.

a. Annealing.

What information can not be obtained from the sequence of a gene? a. Whether the gene is methylated. b. Relationship between two species. c. Amino acid sequence of the protein. d. Effects of mutation on gene function.

a. Whether the gene is methylated.

The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____. a. sticky ends b. base sequences c. single strands d. restriction fragments e. ligases

a. sticky ends

How many DNA molecules would there be after four rounds of PCR if the initial reaction mixture contained two molecules? a. 8 b. 64 c. 32 d. 16

c. 32 Equation is (2^4) x 2 = 32

Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes? a. Use a nucleic acid probe. b. Subject the specimen to amniocentesis. c. Use the polymerase chain reaction. d. Subject the DNA to restriction enzymes. e. Subject the DNA to electrophoresis.

c. Use the polymerase chain reaction.

In recombinant DNA experiments, what is used to cut pieces of DNA and what joins the resulting fragments to form recombinant DNA? a. a transposon ... a restriction enzyme b. a transposon ... a plasmid c. a plasmid ... DNA ligase d. a restriction enzyme ... DNA ligase e. DNA ligase ... a restriction enzyme

d. a restriction enzyme ... DNA ligase

In order to insert a human gene into a plasmid, both must _____ a. have identical DNA sequences b. originate from the same type of cell c. code for the same gene product d. be cut by the same restriction enzyme e. be the same length

d. be cut by the same restriction enzyme

What enzyme forms covalent bonds between restriction fragments? a. DNA primase b. DNA helicase c. single-strand binding protein d. DNA polymerase e. DNA ligase

e. DNA ligase

Which of the following is an example of "recombinant DNA technology?" a. manipulating a meiotic crossing-over event b. cloning genes from homologous pairs of chromosomes c. alternate alleles assorting independently d. combining alternate alleles of a gene in a single cell e. introducing a human gene into a bacterial plasmid

e. introducing a human gene into a bacterial plasmid