Question 1

Nucleotide bases within a single strand of DNA are held together by which of the following bonds?

Accepted Answer

A) phosphodiester 
B) pentose-phosphate 
C) polynucleotide 
D) phosphoester 
A) phosphodiester 
B) pentose-phosphate 
C) polynucleotide 
D) phosphoester

Question 2

Why is the enzyme reverse transcriptase found within retroviral virions?

Accepted Answer

Reverse transcriptase is found within a

Question 3

Cellular protein synthesis proceeds in which direction?

Accepted Answer

A) carboxyl to amino terminus 
B) amino to carboxyl terminus 
C) 3´' to 5´ 
D) 5´ to 3´ 
A) carboxyl to amino terminus 
B) amino to carboxyl terminus 
C) 3´' to 5´ 
D) 5´ to 3´

Question 4

The first stage of protein translation occurs when Met-tRNAᵢᴹᵉᵗ base pairs with the mRNA being translated in the ribosomal:

Accepted Answer

A) P site. 
B) A site. 
C) E site. 
D) T site. 
A) P site. 
B) A site. 
C) E site. 
D) T site.

Question 5

The most common arrangement of protein-coding genes in bacteria are those where the genes encoding proteins that work together are arranged in a contiguous array of DNA called:

Accepted Answer

A) an operon. 
B) a terminator. 
C) a promoter. 
D) an operator. 
A) an operon. 
B) a terminator. 
C) a promoter. 
D) an operator.

Question 6

Which of the following is seen when a single mRNA is simultaneously translated to form multiple copies of a polypeptide chain?

Accepted Answer

A) phagosome 
B) multisome 
C) nucleosome 
D) polysome 
A) phagosome 
B) multisome 
C) nucleosome 
D) polysome

Question 7

A double-stranded piece of DNA containing the sequence GCATGGCCACTACCG has a higher Tm than one containing the sequence GAATGGTAACAACTG.Describe the properties of DNA that make this true.

Accepted Answer

The first sequence contains 10/15 G·C ba

Question 8

Which of the following are enzymes that play a key role in the base excision repair of nucleotide mismatches and damaged bases?

Accepted Answer

A) glycosamines 
B) glycosidases 
C) glycosylases 
D) none of the above 
A) glycosamines 
B) glycosidases 
C) glycosylases 
D) none of the above

Question 9

An enzyme that breaks DNA,dispels the tension,and reseals the strand ahead of a DNA replication growing fork is called a(n)

Accepted Answer

A) topoisomerase. 
B) DNA polymerase. 
C) phosphodiesterase. 
D) aminoacyl-tRNA synthetase. 
A) topoisomerase. 
B) DNA polymerase. 
C) phosphodiesterase. 
D) aminoacyl-tRNA synthetase.

Question 10

Which of the following are removed from mRNAs during processing?

Accepted Answer

A) exons 
B) noncoding sequences 
C) RNA cap structure 
D) poly(
A) tail 
A) exons 
B) noncoding sequences 
C) RNA cap structure 
D) poly(
A) tail

Question 11

Which base pair(s)typically occur(s)in double-stranded DNA?

Accepted Answer

A) G·C 
B) G·T 
C) G·A 
D) G·G 
A) G·C 
B) G·T 
C) G·A 
D) G·G

Question 12

The genetic code is said to be "degenerate" because:

Accepted Answer

A) amino acid sequences are always read in the 3'→5' direction of the mRNA. 
B) amino acids are encoded only by DNA sequences found in introns. 
C) a particular amino acid can be specified by more than one codon. 
D) tryptophan is the first amino acid in all polypeptide chains. 
A) amino acid sequences are always read in the 3'→5' direction of the mRNA. 
B) amino acids are encoded only by DNA sequences found in introns. 
C) a particular amino acid can be specified by more than one codon. 
D) tryptophan is the first amino acid in all polypeptide chains.

Question 13

Silent mutations that occur under a variety of conditions in DNA results in which of the following?

Accepted Answer

A) a stop codon 
B) a change of an amino acid to another 
C) the formation of an anticodon 
D) no change in the amino acid 
A) a stop codon 
B) a change of an amino acid to another 
C) the formation of an anticodon 
D) no change in the amino acid

Question 14

Which of the following is not a recognized stage of protein synthesis in either prokaryotes or eukaryotes?

Accepted Answer

A) elongation 
B) initiation 
C) translation 
D) termination 
A) elongation 
B) initiation 
C) translation 
D) termination

Question 15

In which of these polymers are the monomers added one at a time?

Accepted Answer

A) DNA 
B) rRNA 
C) protein 
D) all of the above 
A) DNA 
B) rRNA 
C) protein 
D) all of the above

Question 16

Which of the following is a protein that is involved in translation?

Accepted Answer

A) topoisomerase 
B) ribosomal RNA 
C) RNA polymerase 
D) aminoacyl-tRNA synthetase 
A) topoisomerase 
B) ribosomal RNA 
C) RNA polymerase 
D) aminoacyl-tRNA synthetase

Question 17

If perfect Watson-Crick base pairing were demanded between codons and anticodons,cells would need 61 different tRNAs.If there are only 20 amino acids used in protein synthesis,how would you explain this excess number of tRNAs compared to amino acids? Conversely,how would you explain the fact that some cells contain fewer than 61 tRNAs?

Accepted Answer

The number of tRNAs in most cells is mor

Question 18

In eukaryotic cells,protein synthesis in the cytoplasm utilizes three types of RNA molecules.Which of the following contains a three nucleotide sequence called the anticodon?

Accepted Answer

A) mRNA 
B) tRNA 
C) rRNA 
D) all of the above 
A) mRNA 
B) tRNA 
C) rRNA 
D) all of the above

Question 19

A Holliday structure is a(n)

Accepted Answer

A) intermediate in genetic recombination. 
B) double-stranded DNA break. 
C) collapsed replication fork. 
D) thymine-thymine dimer. 
A) intermediate in genetic recombination. 
B) double-stranded DNA break. 
C) collapsed replication fork. 
D) thymine-thymine dimer.

Question 20

Okazaki fragments are small fragments of DNA that eventually are ligated to form which of the following strands of DNA?

Accepted Answer

A) lagging 
B) parent 
C) leading 
D) joining 
A) lagging 
B) parent 
C) leading 
D) joining

Exam 5: Fundamental Molecular Genetic Mechanisms

Nucleotide bases within a single strand of DNA are held together by which of the following bonds?

Why is the enzyme reverse transcriptase found within retroviral virions?

Cellular protein synthesis proceeds in which direction?

The first stage of protein translation occurs when Met-tRNAᵢᴹᵉᵗ base pairs with the mRNA being translated in the ribosomal:

The most common arrangement of protein-coding genes in bacteria are those where the genes encoding proteins that work together are arranged in a contiguous array of DNA called:

Which of the following is seen when a single mRNA is simultaneously translated to form multiple copies of a polypeptide chain?

A double-stranded piece of DNA containing the sequence GCATGGCCACTACCG has a higher Tm than one containing the sequence GAATGGTAACAACTG.Describe the properties of DNA that make this true.

Which of the following are enzymes that play a key role in the base excision repair of nucleotide mismatches and damaged bases?

An enzyme that breaks DNA,dispels the tension,and reseals the strand ahead of a DNA replication growing fork is called a(n)

Which of the following are removed from mRNAs during processing?

Which base pair(s)typically occur(s)in double-stranded DNA?

The genetic code is said to be "degenerate" because:

Silent mutations that occur under a variety of conditions in DNA results in which of the following?

Which of the following is not a recognized stage of protein synthesis in either prokaryotes or eukaryotes?

In which of these polymers are the monomers added one at a time?

Which of the following is a protein that is involved in translation?

In eukaryotic cells,protein synthesis in the cytoplasm utilizes three types of RNA molecules.Which of the following contains a three nucleotide sequence called the anticodon?

A Holliday structure is a(n)

Okazaki fragments are small fragments of DNA that eventually are ligated to form which of the following strands of DNA?

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

Nerve Cells

Immunology

Cancer

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