Question 1

Which of the following is a structural and functional component of the ribosome?

Accepted Answer

A) mRNA 
B) tRNA 
C) rRNA 
D) DNA 
E) ATP 
A) mRNA 
B) tRNA 
C) rRNA 
D) DNA 
E) ATP

Question 2

Which statement concerning the double helix structure of DNA is FALSE?

Accepted Answer

A) The helix completes one turn every 10 base pairs. 
B) Base pairs in the double helix are attached by way of hydrogen bonding. 
C) The two strands of the double helix are called parallel strands. 
D) The base pairs are directed in toward the middle of the double helix. 
E) In the double helix,adenine connects to thymine and cytosine connects to guanine. 
A) The helix completes one turn every 10 base pairs. 
B) Base pairs in the double helix are attached by way of hydrogen bonding. 
C) The two strands of the double helix are called parallel strands. 
D) The base pairs are directed in toward the middle of the double helix. 
E) In the double helix,adenine connects to thymine and cytosine connects to guanine.

Question 3

Who first described the three-dimensional structure of DNA in 1953?

Accepted Answer

A) Watson and Crick 
B) Chargaff 
C) Garrow 
D) Mendeleev 
E) Einstein 
A) Watson and Crick 
B) Chargaff 
C) Garrow 
D) Mendeleev 
E) Einstein

Question 4

Which of the following statements concerning nucleic acids is FALSE?

Accepted Answer

A) Nucleic acids are polymers of repeating monomer units called nucleotides. 
B) DNA is responsible for the storage of genetic information. 
C) RNA is responsible for the transfer and expression of genetic information. 
D) A gene is a sequence of bases on a DNA strand that codes for a particular protein. 
E) A chromosome is a complex of 46 DNA molecules intertwined with proteins. 
A) Nucleic acids are polymers of repeating monomer units called nucleotides. 
B) DNA is responsible for the storage of genetic information. 
C) RNA is responsible for the transfer and expression of genetic information. 
D) A gene is a sequence of bases on a DNA strand that codes for a particular protein. 
E) A chromosome is a complex of 46 DNA molecules intertwined with proteins.

Question 5

Adenine present in one strand of a DNA molecule is always hydrogen bonded to what base in the other strand?

Accepted Answer

A) thymine 
B) guanine 
C) cytosine 
D) uracil 
E) adenine 
A) thymine 
B) guanine 
C) cytosine 
D) uracil 
E) adenine

Question 6

One strand of the DNA molecule advances in the 3' → 5' direction.In what direction does its complementary strand advance?

Accepted Answer

A) 3' → 5' 
B) N-terminal to C-terminal 
C) 5' → 3' 
D) O-terminal to P-terminal 
E) There is no set direction for the complementary strand; it depends on the organism. 
A) 3' → 5' 
B) N-terminal to C-terminal 
C) 5' → 3' 
D) O-terminal to P-terminal 
E) There is no set direction for the complementary strand; it depends on the organism.

Question 7

What type of mutation involves the substitution of a single base for another in a codon?

Accepted Answer

A) switch 
B) insertion 
C) point 
D) silent 
E) fragmental 
A) switch 
B) insertion 
C) point 
D) silent 
E) fragmental

Question 8

What is the name for the nucleotide formed from deoxyribose,adenine,and two phosphoryl groups?

Accepted Answer

A) adenosine phosphate 
B) deoxyadenosine phosphate 
C) D-adenine diphosphate 
D) deoxyriboadenine diphosphate 
E) deoxyadenosine diphosphate 
A) adenosine phosphate 
B) deoxyadenosine phosphate 
C) D-adenine diphosphate 
D) deoxyriboadenine diphosphate 
E) deoxyadenosine diphosphate

Question 9

Which statement properly describes the difference between ribose and deoxyribose?

Accepted Answer

A) Ribose is an L-sugar and deoxyribose is a D-sugar. 
B) Deoxyribose has one less oxygen atom than ribose. 
C) Ribose has an α-arrangement and deoxyribose has a β-arrangement. 
D) Ribose is a five-carbon sugar and deoxyribose is a six-carbon sugar. 
E) Deoxyribose has two more hydroxyl groups than ribose. 
A) Ribose is an L-sugar and deoxyribose is a D-sugar. 
B) Deoxyribose has one less oxygen atom than ribose. 
C) Ribose has an α-arrangement and deoxyribose has a β-arrangement. 
D) Ribose is a five-carbon sugar and deoxyribose is a six-carbon sugar. 
E) Deoxyribose has two more hydroxyl groups than ribose.

Question 10

All tRNA molecules have a CCA sequence at their 3' ends.

Accepted Answer

A) True 
 B)False

Question 11

Point mutations always result in a change in the amino acid sequence of the protein encoded by the gene.

Accepted Answer

A) True 
 B)False

Question 12

What is accomplished by the use of gel electrophoresis in DNA analysis?

Accepted Answer

A) separation of DNA fragments according to size 
B) hybridization of DNA fragments 
C) formation of daughter DNA molecules 
D) identification of base composition 
E) rapid DNA synthesis 
A) separation of DNA fragments according to size 
B) hybridization of DNA fragments 
C) formation of daughter DNA molecules 
D) identification of base composition 
E) rapid DNA synthesis

Question 13

What term is used to describe bacterial enzymes that are used to "cut" the sugar-phosphate backbone of DNA molecules at specific nucleotide sequences?

Accepted Answer

A) DNA polymerases 
B) DNA phosphatases 
C) restriction enzymes 
D) retroviral enzymes 
E) reverse transcriptases 
A) DNA polymerases 
B) DNA phosphatases 
C) restriction enzymes 
D) retroviral enzymes 
E) reverse transcriptases

Question 14

In protein synthesis,new amino acids are attached to the N-terminus of the growing peptide chain.

Accepted Answer

A) True 
 B)False

Question 15

Nucleic acids are polymers of nucleotides.Which of the following correctly represents a nucleotide that may be found in nucleic acids?

Accepted Answer

A) I 
B) II 
C) III 
D) I,II,and III 
E) I and IV 
A) I 
B) II 
C) III 
D) I,II,and III 
E) I and IV

Question 16

Base pairing between guanine and cytosine is more stable than base pairing between adenine and thymine.Which of the following best explains why?

Accepted Answer

A) G/C base pairing involves two large purine bases,while A/T base pairing involves two smaller pyrimidine bases. 
B) G/C base pairing involves three hydrogen bonds,while A/T base pairing involves only two hydrogen bonds. 
C) G/C base pairs are smaller and more compact than A/T base pairs. 
D) G/C base pairs are more widely separated and not as crowded as A/T base pairs. 
E) G/C base pairs appear in DNA and RNA,while A/T base pairs appear only in DNA. 
A) G/C base pairing involves two large purine bases,while A/T base pairing involves two smaller pyrimidine bases. 
B) G/C base pairing involves three hydrogen bonds,while A/T base pairing involves only two hydrogen bonds. 
C) G/C base pairs are smaller and more compact than A/T base pairs. 
D) G/C base pairs are more widely separated and not as crowded as A/T base pairs. 
E) G/C base pairs appear in DNA and RNA,while A/T base pairs appear only in DNA.

Question 17

Which structure correctly represents the dinucleotide sequence GC that is found in DNA?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 18

DNA isolated from human cheek cells was found to contain 21% guanine.What else is true about the base composition of this DNA sample?

Accepted Answer

A) It contains 79% cytosine. 
B) It contains 79% adenine and thymine. 
C) It contains 21% adenine,21% cytosine,and 21% thymine. 
D) It contains 21% cytosine,29% adenine,and 29% thymine. 
E) It is impossible to say anything specific about the percentages of adenine,cytosine,and thymine without further analysis. 
A) It contains 79% cytosine. 
B) It contains 79% adenine and thymine. 
C) It contains 21% adenine,21% cytosine,and 21% thymine. 
D) It contains 21% cytosine,29% adenine,and 29% thymine. 
E) It is impossible to say anything specific about the percentages of adenine,cytosine,and thymine without further analysis.

Question 19

RNA splicing involves the removal of nucleotide sequences that do not code for a protein in a newly formed mRNA.What are these nonprotein coding sequences called?

Accepted Answer

A) caps 
B) introns 
C) exons 
D) operons 
E) genes 
A) caps 
B) introns 
C) exons 
D) operons 
E) genes

Question 20

Which statement concerning DNA is FALSE?

Accepted Answer

A) DNA stands for diribonucleic acid. 
B) DNA molecules are located in the nucleus of the cell. 
C) DNA molecules exist tightly wrapped around proteins called histones. 
D) The genetic information of an organism is stored in DNA. 
E) The four common bases found in DNA are adenine,cytosine,guanine,and thymine. 
A) DNA stands for diribonucleic acid. 
B) DNA molecules are located in the nucleus of the cell. 
C) DNA molecules exist tightly wrapped around proteins called histones. 
D) The genetic information of an organism is stored in DNA. 
E) The four common bases found in DNA are adenine,cytosine,guanine,and thymine.

Exam 20: Introduction to Molecular Genetics

Which of the following is a structural and functional component of the ribosome?

Which statement concerning the double helix structure of DNA is FALSE?

Who first described the three-dimensional structure of DNA in 1953?

Which of the following statements concerning nucleic acids is FALSE?

Adenine present in one strand of a DNA molecule is always hydrogen bonded to what base in the other strand?

One strand of the DNA molecule advances in the 3' → 5' direction.In what direction does its complementary strand advance?

What type of mutation involves the substitution of a single base for another in a codon?

What is the name for the nucleotide formed from deoxyribose,adenine,and two phosphoryl groups?

Which statement properly describes the difference between ribose and deoxyribose?

All tRNA molecules have a CCA sequence at their 3' ends.

Point mutations always result in a change in the amino acid sequence of the protein encoded by the gene.

What is accomplished by the use of gel electrophoresis in DNA analysis?

What term is used to describe bacterial enzymes that are used to "cut" the sugar-phosphate backbone of DNA molecules at specific nucleotide sequences?

In protein synthesis,new amino acids are attached to the N-terminus of the growing peptide chain.

Nucleic acids are polymers of nucleotides.Which of the following correctly represents a nucleotide that may be found in nucleic acids?

Base pairing between guanine and cytosine is more stable than base pairing between adenine and thymine.Which of the following best explains why?

Which structure correctly represents the dinucleotide sequence GC that is found in DNA?

DNA isolated from human cheek cells was found to contain 21% guanine.What else is true about the base composition of this DNA sample?

RNA splicing involves the removal of nucleotide sequences that do not code for a protein in a newly formed mRNA.What are these nonprotein coding sequences called?

Which statement concerning DNA is FALSE?

Chemistry - Methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, chemical Changes, and the Chemical Equation

States of Matter: Gases, liquids, and Solids

Solutions

Energy,rate and Equilibrium

Acids and Bases

The Nucleus, radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry

The Unsaturated Hydrocarbons: Alkenes, alkynes, and Aromatics

Alcohols, phenols, thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Carbohydrates

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

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