Chapter 9 Multiple Choice Questions

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. In terms of DNA and RNA structure, what is a nucleotide?

A nucleotide is a heterocyclic base correct incorrect

A nucleotide is a sugar molecule covalently bonded to a heterocyclic base correct incorrect

A nucleotide is a sugar molecule bonded to phosphate group/s and a heterocyclic base correct incorrect

A nucleotide is a heterocyclic base bonded to phosphate group/s correct incorrect

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. DNA exists in a double-stranded form whereas RNA is mainly a single stranded molecule. What is the likely reason for DNA being double stranded?

RNA strands cannot form base pairs correct incorrect

Double stranded DNA is a more stable structure correct incorrect

DNA cannot exist in the single stranded form correct incorrect

It is easier to replicate double stranded DNA than single stranded RNA correct incorrect

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. DNA is an important therapeutic target for the intercalating agent class of drugs. These drugs work by:

Occupying the space between base pairs forming a stable complex. correct incorrect

Forming hydrogen bonds with active site amino acid residues. correct incorrect

Promoting the unwinding of the DNA double helix. correct incorrect

Preventing the formation of base pairs. correct incorrect

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. How many stop codons are there in the genetic code?

1 correct incorrect

2 correct incorrect

3 correct incorrect

4 correct incorrect

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. Which of the following statements is true about DNA polymerase?

DNA polymerase can synthesize mRNA in the 3' to 5' direction correct incorrect

DNA polymerase can synthesize DNA in the 5' to 3' direction correct incorrect

DNA polymerase can synthesize mRNA in the 5' to 3'direction correct incorrect

DNA polymerase can synthesize DNA in the 3' to 5' direction correct incorrect

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. What is the role of topoisomerases in eukaryotic DNA replication?

Topoisomerise enzymes cut, uncoil and reseal the double stranded DNA correct incorrect

Topoisomerise enzymes bind to the origin of replication sites within double stranded DNA correct incorrect

Topoisomerise enzymes open up the double stranded DNA at the replication fork correct incorrect

Topoisomerise enzymes join the Okazaki fragments together with phosphodietster bonds correct incorrect

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. Which of the following statements is true of DNA damage?

All DNA damage results in diseases such as cancer correct incorrect

Most DNA damage is repaired by the cell correct incorrect

All DNA damage is caused by physical, chemical or biological agents correct incorrect

Most DNA damage is advantageous to the cell correct incorrect

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. Why are genetic disorders such as haemophilia and Duchenne muscular dystrophy more prevalent in males than females?

Because they can only be passed on from father to son correct incorrect

Because they are dominant genetic disorders correct incorrect

Because they occur due to spontaneous mutations in the Y-chromosome correct incorrect

Because they are X-linked recessive disorders correct incorrect

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. Which of the following is not a researched means of delivering therapeutic DNA for gene therapy?

Polymers correct incorrect

Liposomes correct incorrect

Bacteria correct incorrect

Viruses correct incorrect

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. Which of the following is NOT an anticancer agent?

doxorubicin correct incorrect

aciclovir correct incorrect

6-mercaptopurine correct incorrect

cytarabine correct incorrect