Question 1

One of the primary functions of RNA molecules is to ________.

Accepted Answer

A)  transmit genetic information to offspring 
B)  function in the synthesis of proteins 
C)  make a copy of itself, thus ensuring genetic continuity 
D)  act as a pattern or blueprint to form DNA 
E)  form the genes of higher organisms 
A)  transmit genetic information to offspring 
B)  function in the synthesis of proteins 
C)  make a copy of itself, thus ensuring genetic continuity 
D)  act as a pattern or blueprint to form DNA 
E)  form the genes of higher organisms B

Question 2

Why do researchers think the first self-replicating molecule was RNA?

Accepted Answer

A)  RNA is the only type of molecule that can catalyze a chemical reaction. 
B)  RNA can carry information and catalyze chemical reactions. 
C)  Self-replicating molecules of RNA exist today, in human cells. 
D)  Fossil evidence of such a molecule was recently discovered. 
A)  RNA is the only type of molecule that can catalyze a chemical reaction. 
B)  RNA can carry information and catalyze chemical reactions. 
C)  Self-replicating molecules of RNA exist today, in human cells. 
D)  Fossil evidence of such a molecule was recently discovered. B

Question 3

Why is it that RNA can catalyze reactions but DNA cannot?

Accepted Answer

A)  The sugar of RNA is much more reactive than the sugar of DNA. 
B)  The bases of RNA are much more reactive than the bases of DNA. 
C)  The phosphate groups of RNA are much more reactive than the phosphate groups of DNA. 
D)  The primary structure of RNA is fundamentally different than the primary structure of DNA. 
A)  The sugar of RNA is much more reactive than the sugar of DNA. 
B)  The bases of RNA are much more reactive than the bases of DNA. 
C)  The phosphate groups of RNA are much more reactive than the phosphate groups of DNA. 
D)  The primary structure of RNA is fundamentally different than the primary structure of DNA. A

Question 4

The work of Bartel's group on the ribozyme RNA replicase supports which conclusion?

Accepted Answer

A)  An RNA world could produce molecules that could self-replicate. 
B)  RNA molecules with variable characteristics could catalyze protein synthesis. 
C)  Ribozymes had to be present in the first cells to generate copies of the genetic material 
D)  Ribozymes were produced randomly through natural selection. 
A)  An RNA world could produce molecules that could self-replicate. 
B)  RNA molecules with variable characteristics could catalyze protein synthesis. 
C)  Ribozymes had to be present in the first cells to generate copies of the genetic material 
D)  Ribozymes were produced randomly through natural selection.

Question 5

Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct?

Accepted Answer

A)  The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. 
B)  The 5' end has a phosphate group attached to the number 5 carbon of ribose. 
C)  The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. 
D)  The 5' end has a carboxyl group attached to the number 5 carbon of ribose. 
E)  The 5' end is the fifth position on one of the nitrogenous bases. 
A)  The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. 
B)  The 5' end has a phosphate group attached to the number 5 carbon of ribose. 
C)  The 5' end has phosphate attached to the number 5 carbon of the nitrogenous base. 
D)  The 5' end has a carboxyl group attached to the number 5 carbon of ribose. 
E)  The 5' end is the fifth position on one of the nitrogenous bases.

Question 6

Both DNA and RNA ________.

Accepted Answer

A)  are information-containing molecules 
B)  show primary, secondary, tertiary, and quaternary structure 
C)  are highly reactive catalysts in cells 
D)  naturally occur as a double helix 
A)  are information-containing molecules 
B)  show primary, secondary, tertiary, and quaternary structure 
C)  are highly reactive catalysts in cells 
D)  naturally occur as a double helix

Question 7

What is/are the variable structure(s) of a nucleotide?

Accepted Answer

A)  the phosphate group 
B)  the sugar 
C)  the base 
D)  the sugar and the base 
A)  the phosphate group 
B)  the sugar 
C)  the base 
D)  the sugar and the base

Question 8

In the context of chemical evolution, DNA's structure is interesting because it suggests a possible copying mechanism. What about DNA's structure facilitates copying?

Accepted Answer

A)  It has the same number of purines and pyrimidines. 
B)  The nitrogenous bases are located on the inside of the double helix. 
C)  The strands of the double helix are complementary. 
D)  DNA always goes from 5 prime to 3 prime. 
A)  It has the same number of purines and pyrimidines. 
B)  The nitrogenous bases are located on the inside of the double helix. 
C)  The strands of the double helix are complementary. 
D)  DNA always goes from 5 prime to 3 prime.

Question 9

If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled?

Accepted Answer

A)  proteins 
B)  cellulose 
C)  amino acids 
D)  nucleic acids 
E)  glucose 
A)  proteins 
B)  cellulose 
C)  amino acids 
D)  nucleic acids 
E)  glucose

Question 10

Which of the following are pyrimidine nitrogenous bases?

Accepted Answer

A)  guanine and adenine 
B)  cytosine and uracil 
C)  thymine and guanine 
D)  ribose and deoxyribose 
E)  adenine and thymine 
A)  guanine and adenine 
B)  cytosine and uracil 
C)  thymine and guanine 
D)  ribose and deoxyribose 
E)  adenine and thymine

Question 11

What feature of single nucleotides provides the energy needed for polymerization when nucleic acids are formed?

Accepted Answer

A)  their methyl groups 
B)  their sugar groups 
C)  their nitrogenous bases 
D)  their phosphate groups 
A)  their methyl groups 
B)  their sugar groups 
C)  their nitrogenous bases 
D)  their phosphate groups

Question 12

What is the difference between a ribonucleotide and a deoxyribonucleotide?

Accepted Answer

A)  Ribonucleotides contain a phosphate group. 
B)  Ribonucleotides have a hydroxyl group on the 2 carbon of their sugar subunit. 
C)  Ribonucleotides contain a sugar with five carbon atoms. 
D)  Ribonucleotides have a hydrogen atom on the 1 carbon of their sugar subunit. 
A)  Ribonucleotides contain a phosphate group. 
B)  Ribonucleotides have a hydroxyl group on the 2 carbon of their sugar subunit. 
C)  Ribonucleotides contain a sugar with five carbon atoms. 
D)  Ribonucleotides have a hydrogen atom on the 1 carbon of their sugar subunit.

Question 13

Which of the following includes all of the pyrimidines found in RNA and DNA?

Accepted Answer

A)  cytosine and uracil 
B)  cytosine and thymine 
C)  cytosine, uracil, and thymine 
D)  cytosine, uracil, and guanine 
A)  cytosine and uracil 
B)  cytosine and thymine 
C)  cytosine, uracil, and thymine 
D)  cytosine, uracil, and guanine

Question 14

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________.

Accepted Answer

A)  5'TAACGT3' 
B)  5'TGCAAT3' 
C)  5'UAACGU3' 
D)  3'UAACGU5' 
E)  5'UGCAAU3' 
A)  5'TAACGT3' 
B)  5'TGCAAT3' 
C)  5'UAACGU3' 
D)  3'UAACGU5' 
E)  5'UGCAAU3'

Question 15

Which of the following did Watson and Crick already know when they were trying to determine the structure of DNA? The number of ________.

Accepted Answer

A)  purines is always larger than the number of pyrimidines 
B)  pyrimidines is always larger than purines 
C)  cytosines is always the same as adenines 
D)  guanines is always the same as thymines 
E)  purines is always the same as pyrimidines 
A)  purines is always larger than the number of pyrimidines 
B)  pyrimidines is always larger than purines 
C)  cytosines is always the same as adenines 
D)  guanines is always the same as thymines 
E)  purines is always the same as pyrimidines

Question 16

What is the structural feature that allows DNA to replicate?

Accepted Answer

A)  sugar-phosphate backbone 
B)  complementary pairing of the nitrogenous bases 
C)  disulfide bonding (bridging) of the two helixes 
D)  twisting of the molecule to form an α-helix 
E)  three-component structure of the nucleotides 
A)  sugar-phosphate backbone 
B)  complementary pairing of the nitrogenous bases 
C)  disulfide bonding (bridging) of the two helixes 
D)  twisting of the molecule to form an α-helix 
E)  three-component structure of the nucleotides

Question 17

In the acid-base reaction described in the preceding paragraph about Nakano's research on RNAs, a proton (H+) is being transferred. What is acting as the proton acceptor?

Accepted Answer

A)  cytosine 
B)  magnesium hydroxide 
C)  the virus 
D)  cytosine, magnesium hydroxide, or the virus 
A)  cytosine 
B)  magnesium hydroxide 
C)  the virus 
D)  cytosine, magnesium hydroxide, or the virus

Question 18

You have a polymer of DNA with 10 adenine bases followed by 10 cytosine bases. If that strand bonded to a strand of 20 thymine bases, how would the double helix shape vary from a typical DNA double helix?

Accepted Answer

A)  The double helix would be longer than normal. 
B)  The double helix would be shorter than normal. 
C)  One strand of the double helix would be longer than the other strand. 
D)  The width of the double helix would vary along the length of the strand. 
A)  The double helix would be longer than normal. 
B)  The double helix would be shorter than normal. 
C)  One strand of the double helix would be longer than the other strand. 
D)  The width of the double helix would vary along the length of the strand.

Question 19

Which of the following best describes DNA's secondary structure?

Accepted Answer

A)  beta-pleated sheet 
B)  double parallel helical strands 
C)  turn-loop-turn 
D)  double antiparallel helical strands 
A)  beta-pleated sheet 
B)  double parallel helical strands 
C)  turn-loop-turn 
D)  double antiparallel helical strands

Question 20

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

Accepted Answer

A)  The two strands of the double helix would separate. 
B)  The phosphodiester linkages of the polynucleotide backbone would be broken. 
C)  The purines would be separated from the deoxyribose sugars. 
D)  The pyrimidines would be separated from the deoxyribose sugars. 
E)  All bases would be separated from the deoxyribose sugars. 
A)  The two strands of the double helix would separate. 
B)  The phosphodiester linkages of the polynucleotide backbone would be broken. 
C)  The purines would be separated from the deoxyribose sugars. 
D)  The pyrimidines would be separated from the deoxyribose sugars. 
E)  All bases would be separated from the deoxyribose sugars.

Exam 4: Nucleic Acids and the Rna World

One of the primary functions of RNA molecules is to ________.

Why do researchers think the first self-replicating molecule was RNA?

Why is it that RNA can catalyze reactions but DNA cannot?

The work of Bartel's group on the ribozyme RNA replicase supports which conclusion?

Which of the following statements about the 5' end of a polynucleotide strand of RNA is correct?

Both DNA and RNA ________.

What is/are the variable structure(s) of a nucleotide?

In the context of chemical evolution, DNA's structure is interesting because it suggests a possible copying mechanism. What about DNA's structure facilitates copying?

If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled?

Which of the following are pyrimidine nitrogenous bases?

What feature of single nucleotides provides the energy needed for polymerization when nucleic acids are formed?

What is the difference between a ribonucleotide and a deoxyribonucleotide?

Which of the following includes all of the pyrimidines found in RNA and DNA?

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________.

Which of the following did Watson and Crick already know when they were trying to determine the structure of DNA? The number of ________.

What is the structural feature that allows DNA to replicate?

In the acid-base reaction described in the preceding paragraph about Nakano's research on RNAs, a proton (H+) is being transferred. What is acting as the proton acceptor?

You have a polymer of DNA with 10 adenine bases followed by 10 cytosine bases. If that strand bonded to a strand of 20 thymine bases, how would the double helix shape vary from a typical DNA double helix?

Which of the following best describes DNA's secondary structure?

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

Filters