Molecular Biology Quiz

What is the minimum number of base pairs required for restriction endonucleases to function?

Which type of restriction endonucleases are most important in gene cloning?

What does the enzyme DNase I target in a DNA molecule?

Which enzyme attaches to a short single-stranded region in a mainly double-stranded DNA molecule?

What are sticky ends in DNA manipulation?

What is the function of the Klenow fragment?

Which enzyme is thermostable and used in PCR?

What are linkers in DNA manipulation?

What is the primary purpose of gene cloning experiments?

What is the function of nucleases in DNA manipulation?

Which enzyme is used to synthesize a DNA strand complementary to an RNA template?

What type of enzyme is used to remove phosphate groups from the 5′ terminus of a DNA molecule?

Which type of nuclease removes nucleotides one at a time from the end of a DNA molecule?

What is the role of DNA ligase during DNA replication?

Which enzyme is commonly used in the polymerase chain reaction (PCR)?

What are the two examples of DNA manipulative techniques mentioned?

The primary purpose of gene cloning experiments is to construct recombinant DNA molecules.
Gene cloning involves DNA manipulation techniques, such as cutting and joining DNA.

Nucleases are enzymes that degrade DNA molecules by breaking phosphodiester bonds.
Ligase enzymes are involved in joining nucleic acid molecules together.
DNA polymerase is an enzyme used in the polymerase chain reaction (PCR).
Alkaline phosphatase is an enzyme that removes phosphate groups from the 5′ terminus of a DNA molecule.
Exonucleases are enzymes that remove nucleotides one at a time from the end of a DNA molecule.
Endonucleases are enzymes that cleave DNA at specific internal sites.

Taq DNA polymerase is a thermostable enzyme commonly used in PCR.
Reverse transcriptase is an enzyme that synthesizes a DNA strand complementary to an RNA template.
Terminal deoxynucleotidyl transferase is an enzyme that adds deoxyribonucleotides onto the 3′ terminus of a DNA molecule.
S1 endonuclease is an enzyme purified from the fungus Aspergillus oryzae.
Deoxyribonuclease I (DNase I) is an enzyme that targets any internal phosphodiester bond in a DNA molecule.

Over 1000 different restriction endonucleases have been isolated.
Type II restriction endonucleases are the most important in gene cloning.
Sticky ends are ends of DNA that can form base pairs with complementary sequences.
Linkers are short pieces of double-stranded DNA with a known sequence, used in DNA manipulation.
A problem that can arise when using linkers is that they can form dimers.