Question 1

The 2009 H1N1 flu virus

Accepted Answer

A) was an avian flu virus. 
B) was spread by mosquitoes. 
C) evolved through the genetic reshuffling of viruses that infect humans, birds, and pigs. 
D) killed over 50 million people worldwide. 
A) was an avian flu virus. 
B) was spread by mosquitoes. 
C) evolved through the genetic reshuffling of viruses that infect humans, birds, and pigs. 
D) killed over 50 million people worldwide. C

Question 2

Which of the following statements is false?

Accepted Answer

A) Translation consists of initiation, elongation, and termination. 
B) During polypeptide initiation, an mRNA molecule, the first amino acid attached to its tRNA, and the two subunits of a ribosome are brought together. 
C) The start codon can be different depending on what kind of protein is to be translated. 
D) During the first step of initiation, an mRNA molecule binds to a small ribosomal subunit. 
A) Translation consists of initiation, elongation, and termination. 
B) During polypeptide initiation, an mRNA molecule, the first amino acid attached to its tRNA, and the two subunits of a ribosome are brought together. 
C) The start codon can be different depending on what kind of protein is to be translated. 
D) During the first step of initiation, an mRNA molecule binds to a small ribosomal subunit. C

Question 3

Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids)are

Accepted Answer

A) single nucleotides. 
B) two-nucleotide sequences. 
C) three-nucleotide sequences. 
D) nucleotide sequences of various lengths. 
A) single nucleotides. 
B) two-nucleotide sequences. 
C) three-nucleotide sequences. 
D) nucleotide sequences of various lengths. C

Question 4

Conjugation

Accepted Answer

A) is the direct transfer of DNA from one bacterium to another. 
B) occurs when a bacterium acquires DNA from the surrounding environment. 
C) is the result of crossing over. 
D) occurs when a phage transfers bacterial DNA from one bacterium to another. 
A) is the direct transfer of DNA from one bacterium to another. 
B) occurs when a bacterium acquires DNA from the surrounding environment. 
C) is the result of crossing over. 
D) occurs when a phage transfers bacterial DNA from one bacterium to another.

Question 5

After reading the paragraphs below, answer the questions that follow.
Exposure to the HIV virus doesn't necessarily mean that a person will develop AIDS. Some people have genetic resistance to infection by HIV. Dr. Stephen O'Brien from the U.S. National Cancer Institute has recently identified a mutant form of a gene, called CCR5, that can protect against HIV infection. The mutation probably originated in Europe among survivors of the bubonic plague. The mutated gene prevents the plague bacteria from attaching to cell membranes and, therefore, from entering and infecting body cells.
Although the HIV virus is very different from the bacteria that causes the plague, both diseases affect the exact same cells and use the same method of infection. The presence of the mutated gene in descendants of plague survivors helps prevent them from contracting AIDS. Pharmaceutical companies are using this information as the basis for a new approach to AIDS prevention. This could be very important in areas of the world where the mutation is scarce or absent, such as Africa.
-Imagine that a pharmaceutical company was successful at producing a drug based on the CCR5 gene product that is effective at preventing the contraction of AIDS. However, shortly after the drug has been in use, patients and doctors report that the drug is not as effective as it once was. What is the most likely explanation for this result?

Accepted Answer

A) The people taking the drug have built up a tolerance to the drug. 
B) Some HIV viruses have genetic variations in the RNA genome that provide resistance to the actions of the drug. 
C) The HIV virus gained mutations in its DNA genome in order to become resistant to the actions of the drug. 
D) The DNA of white blood cells of the people taking the drug have mutated to become resistant to the drug. 
A) The people taking the drug have built up a tolerance to the drug. 
B) Some HIV viruses have genetic variations in the RNA genome that provide resistance to the actions of the drug. 
C) The HIV virus gained mutations in its DNA genome in order to become resistant to the actions of the drug. 
D) The DNA of white blood cells of the people taking the drug have mutated to become resistant to the drug.

Question 6

How would the shape of a DNA molecule change if adenine paired with guanine and cytosine paired with thymine?

Accepted Answer

A) The DNA molecule would be longer. 
B) The DNA molecule would be shorter. 
C) The DNA molecule would be circular. 
D) The DNA molecule would have irregular widths along its length. 
A) The DNA molecule would be longer. 
B) The DNA molecule would be shorter. 
C) The DNA molecule would be circular. 
D) The DNA molecule would have irregular widths along its length.

Question 7

The monomers of DNA and RNA are

Accepted Answer

A) monosaccharides. 
B) nucleotides. 
C) fatty acids. 
D) nucleic acids. 
A) monosaccharides. 
B) nucleotides. 
C) fatty acids. 
D) nucleic acids.

Question 8

If one strand of DNA is CGGTAC, then the corresponding strand would be

Accepted Answer

A) GCCTAG. 
B) GCCAUC. 
C) TAACGT. 
D) GCCATG. 
A) GCCTAG. 
B) GCCAUC. 
C) TAACGT. 
D) GCCATG.

Question 9

In the 1920s, Frederick Griffith conducted an experiment in which he mixed the dead cells of a bacterial strain that can cause pneumonia with live cells of a bacterial strain that cannot. When he cultured the live cells, some of the daughter colonies proved able to cause pneumonia. Which of the following processes of bacterial DNA transfer does this experiment demonstrate?

Accepted Answer

A) transduction 
B) conjugation 
C) transformation 
D) transposition 
A) transduction 
B) conjugation 
C) transformation 
D) transposition

Question 10

Which of the following statements regarding the flow of genetic information is false?

Accepted Answer

A) Polypeptides form proteins that determine the appearance and function of the cell and organism. 
B) Eukaryotic mRNA is processed in several ways before export out of the nucleus. 
C) Transcription occurs in the cytoplasm of eukaryotic cells. 
D) Ribosomes function as factories that coordinate the functioning of mRNA and tRNA. 
A) Polypeptides form proteins that determine the appearance and function of the cell and organism. 
B) Eukaryotic mRNA is processed in several ways before export out of the nucleus. 
C) Transcription occurs in the cytoplasm of eukaryotic cells. 
D) Ribosomes function as factories that coordinate the functioning of mRNA and tRNA.

Question 11

Multiple origins of replication on the DNA molecules of eukaryotic cells serve to

Accepted Answer

A) remove errors in DNA replication. 
B) create multiple copies of the DNA molecule at the same time. 
C) shorten the time necessary for DNA replication. 
D) assure the correct orientation of the two strands in the newly growing double helix. 
A) remove errors in DNA replication. 
B) create multiple copies of the DNA molecule at the same time. 
C) shorten the time necessary for DNA replication. 
D) assure the correct orientation of the two strands in the newly growing double helix.

Question 12

When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm?

Accepted Answer

A) the whole phage 
B) only the RNA 
C) only the DNA 
D) the protein "headpiece" and its enclosed nucleic acid 
A) the whole phage 
B) only the RNA 
C) only the DNA 
D) the protein "headpiece" and its enclosed nucleic acid

Question 13

Which of the following statements about ribosomes is false?

Accepted Answer

A) A ribosome consists of two subunits. 
B) Ribosomal subunits are made of proteins and ribosomal RNA. 
C) The ribosomes of prokaryotes and eukaryotes are the exactly the same in structure and function. 
D) Each ribosome has two binding sites for tRNA molecules. 
A) A ribosome consists of two subunits. 
B) Ribosomal subunits are made of proteins and ribosomal RNA. 
C) The ribosomes of prokaryotes and eukaryotes are the exactly the same in structure and function. 
D) Each ribosome has two binding sites for tRNA molecules.

Question 14

Which of the following people conducted the experiments that demonstrated that DNA is the genetic material of bacteriophages?

Accepted Answer

A) Watson and Crick 
B) Hershey and Chase 
C) Franklin 
D) Pauling 
A) Watson and Crick 
B) Hershey and Chase 
C) Franklin 
D) Pauling

Question 15

Which of the following options most accurately lists the sequence of events in translation?

Accepted Answer

A) codon recognition → translocation → peptide bond formation → termination 
B) peptide bond formation → codon recognition → translocation → termination 
C) codon recognition → peptide bond formation → translocation → termination 
D) codon recognition → peptide bond formation → termination → translocation 
A) codon recognition → translocation → peptide bond formation → termination 
B) peptide bond formation → codon recognition → translocation → termination 
C) codon recognition → peptide bond formation → translocation → termination 
D) codon recognition → peptide bond formation → termination → translocation

Question 16

Which of the following statements about herpesviruses is false?

Accepted Answer

A) Herpesviruses reproduce inside the host cell's mitochondria. 
B) Herpesviruses acquire their envelopes from the host cell nuclear membrane. 
C) Herpesviruses may remain dormant for long periods of time while inside the host cell nucleus. 
D) Herpesviruses may cause cold sores or genital sores to appear during times of physical or emotional stress. 
A) Herpesviruses reproduce inside the host cell's mitochondria. 
B) Herpesviruses acquire their envelopes from the host cell nuclear membrane. 
C) Herpesviruses may remain dormant for long periods of time while inside the host cell nucleus. 
D) Herpesviruses may cause cold sores or genital sores to appear during times of physical or emotional stress.

Question 17

Any change in the nucleotide sequence of DNA is called

Accepted Answer

A) a mutation. 
B) a mutagen. 
C) a base substitution. 
D) an anticodon. 
A) a mutation. 
B) a mutagen. 
C) a base substitution. 
D) an anticodon.

Question 18

The copying mechanism of DNA is most like

Accepted Answer

A) taking a picture of yourself and of your reflection in a mirror. 
B) mixing flour, sugar, and water to make bread dough. 
C) dripping water out of a faucet. 
D) carving a figure out of wood. 
A) taking a picture of yourself and of your reflection in a mirror. 
B) mixing flour, sugar, and water to make bread dough. 
C) dripping water out of a faucet. 
D) carving a figure out of wood.

Question 19

Which of the following human activities has contributed to an increase in the number of bacteria having R plasmids?

Accepted Answer

A) nitrogen fixation by genetically engineered plants 
B) improper use of restriction enzymes in research and medical facilities 
C) increased carcinogen exposure from excessive fossil fuel burning 
D) heavy use of antibiotics in medicine and in agriculture 
A) nitrogen fixation by genetically engineered plants 
B) improper use of restriction enzymes in research and medical facilities 
C) increased carcinogen exposure from excessive fossil fuel burning 
D) heavy use of antibiotics in medicine and in agriculture

Question 20

Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like a frameshift mutation?

Accepted Answer

A) The did dog not eat. 
B) The dod idn ote at. 
C) The did not eat. 
D) The dog did dog did not eat. 
A) The did dog not eat. 
B) The dod idn ote at. 
C) The did not eat. 
D) The dog did dog did not eat.

Exam 10: Molecular Biology of the Gene

The 2009 H1N1 flu virus

Which of the following statements is false?

Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids)are

Conjugation

How would the shape of a DNA molecule change if adenine paired with guanine and cytosine paired with thymine?

The monomers of DNA and RNA are

If one strand of DNA is CGGTAC, then the corresponding strand would be

Which of the following statements regarding the flow of genetic information is false?

Multiple origins of replication on the DNA molecules of eukaryotic cells serve to

When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm?

Which of the following statements about ribosomes is false?

Which of the following people conducted the experiments that demonstrated that DNA is the genetic material of bacteriophages?

Which of the following options most accurately lists the sequence of events in translation?

Which of the following statements about herpesviruses is false?

Any change in the nucleotide sequence of DNA is called

The copying mechanism of DNA is most like

Which of the following human activities has contributed to an increase in the number of bacteria having R plasmids?

Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like a frameshift mutation?

Biology: Exploring Life

The Chemical Basis of Life

The Molecules of Cells

A Tour of the Cell

The Working Cell

How Cells Harvest Chemical Energy

Photosynthesis: Using Light to Make Food

The Cellular Basis of Reproduction and Inheritance

Patterns of Inheritance

How Genes Are Controlled

DNA Technology and Genomics

How Populations Evolve

The Origin of Species

Tracing Evolutionary History

Microbial Life: Prokaryotes and Protists

The Evolution of Plant and Fungal Diversity

The Evolution of Invertebrate Diversity

The Evolution of Vertebrate Diversity

Unifying Concepts of Animal Structure and Function

Nutrition and Digestion

Gas Exchange

Circulation

the Immune System

Control of Body Temperature and Water Balance

Hormones and the Endocrine System

Reproduction and Embryonic Development

Nervous Systems

the Senses

How Animals Move

Plant Structure, Growth, and Reproduction

Plant Nutrition and Transport

Control Systems in Plants

the Biosphere: an Introduction to Earths Diverse Environments

Behavioral Adaptations to the Environment

Population Ecology

Communities and Ecosystems

Conservation Biology

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