Chapter 12 Mixed Quizzes

These dimers weaken...

=A) Hydrogen bonds. B) Sulfide bonds. C) Covalent bonds. D) Ionic bonds. E) All of these.

In light repair

=A) The covalent bonds between the thymine dimers are broken B) A single thymine is excised C) The damaged segment of DNA is excised by DNA polymerase D) The damaged segment of DNA is excised by DNA ligase

A mutation that changes a single nucleotide can result in a different amino acid being added into a protein.

=A) True B) False

A transposon can move from a host cell to a plasmid

=A) True B) False

A transposon can move from the host DNA to a plasmid.

=A) True B) False

A transposon enters a cell on a plasmid.

=A) True B) False

Chemical agents can induce mutations.

=A) True B) False

DNA mutations are passed on to a cell's progeny.

=A) True B) False

In dark repair, the final phosphodiester bond is formed by DNA ligase.

=A) True B) False

The addition of a single nucleotide to the DNA sequence causes a frameshift mutation.

=A) True B) False

The repair of a thymine dimer using light involves the splitting of the dimer and reformation of the two thymines.

=A) True B) False

After a tautomeric shift in adenine

A) Adenine bonds with thymine B) Adenine bonds with urasil =C) Adenine bonds with cytosine D) Adenine is unable to bond with any molecule

A nucleotide deletion in DNA replication

A) Causes one amino acid of the protein to be incorrect B) Causes all of the amino acids of the protein to be incorrect =C) Causes the amino acids inserted after the deletion to be incorrect D) Causes the amino acids inserted before the deletion to be incorrect E) Has no effect on the resulting protein

UV light damages DNA by causing

A) Covalent bonds to form between two cytosines next to each other on the same DNA strand =B) Covalent bonds to form between thymine nucleotides next to each other on the same DNA strand C) Covalent bonds to form between two thymine nucleotides on opposing DNA strands D) Covalent bonds to form between a thymine and an adenine on the same DNA strand

UV light and other ionizing radiations damage DNA molecules by...

A) Creating guanine dimmers between adjacent guanines in the DNA chain. B) Creating adenine dimmers between adjacent adenines in the DNA chain. =C) Creating thymine dimmers between adjacent thymines in the DNA chain. D) Creating uracil dimmers between adjacent uracils in the DNA chain. E) Creating cytosine dimmers between adjacent cytosines in the DNA chain.

The enzyme _______ catalyzes thymine dimer repair.

A) DNA isomerase B) DNA ligase =C) DNA photolyase D) DNA phosphatase E) DNA transferase

Which of the following synthesizes the new DNA strand?

A) DNA ligase =B) DNA polymerase C) DNA helicase D) UvrA-UvrB trimer

When DNA is damaged by UV light and is not repaired

A) DNA replication can proceed as normal but transcription is prevented B) Transcription can proceed as normal but replication is prevented =C) Neither DNA replication nor transcription can occur and the organism will probably die D) The damaged part will be excised and allow DNA replication to proceed

In a tautomeric shift

A) It is always adenine that is changed B) Final bonding of nucleotides remains unchanged C) Adenine is changed so it can no longer form base pairs =D) Hydrogen atoms move to form a base with altered hydrogen properties E) Carbon atoms move to form a base with altered properties

A transposon can do all of the following except

A) Move from a plasmid into the recipient cell genome B) Move from one site on the host genome to another site on the host genome C) Move from a host genome to a plasmid D) Make a copy of itself, leaving the copy in the original position as it moves =E) Lyse the host chromosome to which it is transferred

The enzyme methylguanine-DNA methyltransferase

A) Removes entire guanine residues and replaces them with methyl groups. =B) Removes methyl groups from the oxygen attached at the 6-position of guanines. C) Removes methyl groups from the nitrogen attached at the 6-position of guanines. D) Adds methyl groups to the oxygen attached at the 6-position of guanines. E) Adds methyl groups to the nitrogen attached at the 6-position of guanines.

Transposons are made of

A) Segments of RNA =B) Segments of DNA C) Antibody D) Protein

Transposons are...

A) Segments of messenger RNA. B) Transposable elements. C) Plasmids. =D) Segments of DNA. E) Segments of transfer RNA.

These dimers are repaired by...

A) The enzyme DNA photolyase. B) Exposure to light. C) Transfer of an electron to the dimer. D) A and B. =E) A, B and C.

If a frameshift mutation causes a stop codon to be inserted into the DNA sequence

A) The resulting protein will not be affected B) The phenotype will change but not the genotype =C) The resulting protein will be too short and non-functional D) the resulting protein will be too long and non-functional

Which of the following is not true about transposons?

A) They are capable of shifting from one cell to another B) They can move into the host genome C) They can move from one site in the host genome to another site =D) Is able to leave the host genome via a vector E) Replicate themselves before moving

Transposons are..

A) Transported by transduction. B) Transported by a sex pilus. C) Transported by conjugation. D) Transported by bacteriophages. =E) Transported by plasmids.

A transposon enters a bacterial cell by a bacteriophage.

A) True =B) False

Chemical agents can cause mutations by inducing ethylation of guanine residues in DNA.

A) True =B) False

Excision repair takes place only in the presence of light.

A) True =B) False

In a frameshift mutation all of the amino acids before the shift are changed.

A) True =B) False

In nucleotide excision repair, both strands of the DNA are cut and repaired using DNA polymerase and DNA ligase.

A) True =B) False

Nucleotide excision repair only repairs pyrimidine dimers.

A) True =B) False

The enzyme ethyl-guanine-DNA ethyltransferase prevents DNA mutations from occuring.

A) True =B) False

When a transposon moves within a host cell, it

A) Undergoes transformation B) Always removes all traces of itself from the original location =C) Sometimes leaves a copy of itself at the original location D) Changes its DNA in the process

What protein cuts the damaged DNA strand?

A) UvrB =B) UvrC C) UvrD D) UvrA

Which protein has a helicase function?

A) UvrB B) UvrC =C) UvrD D) UvrA

A mutation that causes a change in a single nucleotide in DNA

A) Will have no effect on the resulting protein =B) Changes the corresponding nucleotide in mRNA, resulting in a different codon C) Causes the codon to be correct, but the anticodon to be incorrect D) Causes protein synthesis to stop

Thymine dimers are mutations that are commonly caused by

A) X-rays. =B) UV light. C) Heat. D) Antibiotics. E) Disinfectants.

The nucleic acid sequence in mRNA is determined by

A) the order of amino acids in the protein =B) nucleotide sequence in DNA C) nucleotide sequence in t-RNA D) All of the above.