Question 1

Which of the following is a characteristic of transposons?

Accepted Answer

A) a major force in evolution 
B) segments of DNA moved non-enzymatically in the genome 
C) stable location within genome 
D) range in size no more than hundreds of bps 
A) a major force in evolution 
B) segments of DNA moved non-enzymatically in the genome 
C) stable location within genome 
D) range in size no more than hundreds of bps

Question 2

Which of the following provides for genetic variability within species and,ultimately,the evolution of new species?

Accepted Answer

A) DNA repair and DNA glycosylase activity 
B) DNA glycosylase activity and recombination 
C) recombination and mutations 
D) mutations and DNA glycosylase activity 
A) DNA repair and DNA glycosylase activity 
B) DNA glycosylase activity and recombination 
C) recombination and mutations 
D) mutations and DNA glycosylase activity

Question 3

Which of the following is a characteristic of Okazaki fragments?

Accepted Answer

A) about 20-30 nucleotides in length 
B) newly synthesized large lagging strand fragments 
C) synthesis performed in the 3'5' direction 
D) initiated with an RNA primer 
A) about 20-30 nucleotides in length 
B) newly synthesized large lagging strand fragments 
C) synthesis performed in the 3'5' direction 
D) initiated with an RNA primer

Question 4

Which of the following mutations can occur when the thymine analog,5-bromouracil,incorporates into DNA normally occupied by thymine?

Accepted Answer

A) T-A to A-T 
B) G-C to C-G 
C) U-A to A-U 
D) C-G to T-A 
A) T-A to A-T 
B) G-C to C-G 
C) U-A to A-U 
D) C-G to T-A

Question 5

Which of the following is NOT a characteristic of the DNA strand exchange reaction?

Accepted Answer

A) It is ATP-dependent. 
B) It is catalyzed by RecA protein. 
C) It requires DNA polymerase I. 
D) Its complex has 3'-terminal ssDNA affinity for other DNA termini. 
A) It is ATP-dependent. 
B) It is catalyzed by RecA protein. 
C) It requires DNA polymerase I. 
D) Its complex has 3'-terminal ssDNA affinity for other DNA termini.

Question 6

Which of the following is a characteristic of E.coli DNA polymerase I?

Accepted Answer

A) a 5'?3' exonuclease activity 
B) a 3'?5' DNA polymerase activity 
C) modest processivity (approximately 20 nucleotides) 
D) does not require a primer for initiation 
A) a 5'?3' exonuclease activity 
B) a 3'?5' DNA polymerase activity 
C) modest processivity (approximately 20 nucleotides) 
D) does not require a primer for initiation

Question 7

Which of the following nucleotides would replace T in a transversion mutation?

Accepted Answer

A) A 
B) C 
C) U 
D) T 
A) A 
B) C 
C) U 
D) T

Question 8

Nitrous acid causes the oxidative deamination of cytosine,producing uracil.Which of the following point mutations is the logical result?

Accepted Answer

A) T-A to G-C 
B) C-G to T-A 
C) C-G to G-C 
D) T-A to A-T 
A) T-A to G-C 
B) C-G to T-A 
C) C-G to G-C 
D) T-A to A-T

Question 9

Eukaryotic cells have replication regions called replicators that occur every 3-300 kbp.Which of the following terms defines the units of replication?

Accepted Answer

A) replication forks 
B) replication arms 
C) replicons 
D) replicators 
A) replication forks 
B) replication arms 
C) replicons 
D) replicators

Question 10

Which of the following processes are B-cells,T-cells,and macrophages capable of that allows them to produce antibodies essential to the immune response?

Accepted Answer

A) replication rearrangement 
B) complementarity modification 
C) DNA replication 
D) DNA rearrangement 
A) replication rearrangement 
B) complementarity modification 
C) DNA replication 
D) DNA rearrangement

Question 11

Which of the following does a pair of b-subunits of DNA polymerase III form in order to tether the polymerase to the template,thus increasing the processivity of the polymerase?

Accepted Answer

A) a ligase 
B) a sliding clamp 
C) a primer binding site 
D) a loop of DNA 
A) a ligase 
B) a sliding clamp 
C) a primer binding site 
D) a loop of DNA

Question 12

Which of the following types of mechanisms defines DNA replication?

Accepted Answer

A) dispersive 
B) conservative 
C) semiconservative 
D) liberal 
A) dispersive 
B) conservative 
C) semiconservative 
D) liberal

Question 13

Which of the following is a feature of E.coli replication on the lagging strand?

Accepted Answer

A) It is primarily carried out by DNA polymerase I. 
B) It is initially synthesized as Okazaki fragments. 
C) It is synthesized continuously. 
D) It is performed in a 3'5' direction of synthesis. 
A) It is primarily carried out by DNA polymerase I. 
B) It is initially synthesized as Okazaki fragments. 
C) It is synthesized continuously. 
D) It is performed in a 3'5' direction of synthesis.

Question 14

Which of the following is a property of DNA polymerase III?

Accepted Answer

A) It is responsible for incorporating most of the nucleotides in the leading strand. 
B) It is a large protein complex containing more than 5 subunits. 
C) It synthesizes most of the leading strand prior to aiding in the synthesis of the lagging strand. 
D) It has lesser processivity than DNA polymerase I. 
A) It is responsible for incorporating most of the nucleotides in the leading strand. 
B) It is a large protein complex containing more than 5 subunits. 
C) It synthesizes most of the leading strand prior to aiding in the synthesis of the lagging strand. 
D) It has lesser processivity than DNA polymerase I.

Question 15

Which of the following is a characteristic of the 3'-exonuclease activity of DNA polymerase I of E.coli?

Accepted Answer

A) It is relatively fast compared to polymerase activity. 
B) It removes nucleotides that do not base pair at the 5'-end of the growing chain. 
C) It is similar to the polymerase activity. 
D) It is an editor of polymerase activity. 
A) It is relatively fast compared to polymerase activity. 
B) It removes nucleotides that do not base pair at the 5'-end of the growing chain. 
C) It is similar to the polymerase activity. 
D) It is an editor of polymerase activity.

Question 16

Which of the following enzymes seals nicks in dsDNA where a 3'-OH and 5'-phosphate are juxtapositioned?

Accepted Answer

A) DNA polymerase I 
B) DNA gyrase 
C) DNA polymerase III 
D) DNA ligase 
A) DNA polymerase I 
B) DNA gyrase 
C) DNA polymerase III 
D) DNA ligase

Question 17

Which of the following proteins binds ssDNA,forming a nucleoprotein filament capable of strand invasion and homologous pairing in general recombination in E.coli?

Accepted Answer

A) RecA 
B) RuvB 
C) RuvA 
D) RecBCD complex 
A) RecA 
B) RuvB 
C) RuvA 
D) RecBCD complex

Question 18

How many distinct catalytic active sites does E.coli DNA polymerase I have on its single polypeptide chain?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
A) 1 
B) 2 
C) 3 
D) 4

Question 19

Which of the following actions does the methyl-directed repair system take when it detects a mismatch in dsDNA?

Accepted Answer

A) It resynthesizes the newly replicated strand. 
B) It corrects the DNA strand that is methylated. 
C) It corrects the mismatch by changing the base on the not-yet-methylated strand. 
D) It changes the base that is methylated. 
A) It resynthesizes the newly replicated strand. 
B) It corrects the DNA strand that is methylated. 
C) It corrects the mismatch by changing the base on the not-yet-methylated strand. 
D) It changes the base that is methylated.

Question 20

Which of the following is NOT a step in mammalian nucleotide excision repair?

Accepted Answer

A) Lesions are recognized by XPA protein. 
B) Sugar-phosphate backbone is cut in 1 place. 
C) The resulting gap is filled in by DNA polymerases. 
D) DNA backbone is closed with DNA ligase. 
A) Lesions are recognized by XPA protein. 
B) Sugar-phosphate backbone is cut in 1 place. 
C) The resulting gap is filled in by DNA polymerases. 
D) DNA backbone is closed with DNA ligase.

Exam 28: DNA Metabolism: Replication, recombination, and Repair

Which of the following is a characteristic of transposons?

Which of the following provides for genetic variability within species and,ultimately,the evolution of new species?

Which of the following is a characteristic of Okazaki fragments?

Which of the following mutations can occur when the thymine analog,5-bromouracil,incorporates into DNA normally occupied by thymine?

Which of the following is NOT a characteristic of the DNA strand exchange reaction?

Which of the following is a characteristic of E.coli DNA polymerase I?

Which of the following nucleotides would replace T in a transversion mutation?

Nitrous acid causes the oxidative deamination of cytosine,producing uracil.Which of the following point mutations is the logical result?

Eukaryotic cells have replication regions called replicators that occur every 3-300 kbp.Which of the following terms defines the units of replication?

Which of the following processes are B-cells,T-cells,and macrophages capable of that allows them to produce antibodies essential to the immune response?

Which of the following does a pair of b-subunits of DNA polymerase III form in order to tether the polymerase to the template,thus increasing the processivity of the polymerase?

Which of the following types of mechanisms defines DNA replication?

Which of the following is a feature of E.coli replication on the lagging strand?

Which of the following is a property of DNA polymerase III?

Which of the following is a characteristic of the 3'-exonuclease activity of DNA polymerase I of E.coli?

Which of the following enzymes seals nicks in dsDNA where a 3'-OH and 5'-phosphate are juxtapositioned?

Which of the following proteins binds ssDNA,forming a nucleoprotein filament capable of strand invasion and homologous pairing in general recombination in E.coli?

How many distinct catalytic active sites does E.coli DNA polymerase I have on its single polypeptide chain?

Which of the following actions does the methyl-directed repair system take when it detects a mismatch in dsDNA?

Which of the following is NOT a step in mammalian nucleotide excision repair?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Lipid Biosynthesis

Membranes and Membrane Transport

The Reception and Transmission of Extracellular Information

Enzymes Kinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Nutrition and the Organization of Metabolism

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Nitrogen Acquisition and Amino Acid Metabolism

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Synthesis and Degradation of Nucleotides

Recombinant Dna: Cloning and Creation of Chimeric Genes

Transcription and the Regulation of Gene Expression

Protein Synthesis

Post-Transcriptional Regulation of Gene Expression

Completing the Protein Life Cycle: Folding, processing, and Degradation

Metabolic Integration and Organ Specialization

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