Chapter 10 mastering bio

In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon. 2' ... 3' 2' ... 1' 1' ... 3' 1' ... 5' 1' ... 2'

1' ... 5'

The directions for each amino acid in a polypeptide are indicated by a codon that consists of ________ nucleotides in an RNA molecule. 3 5 2 4

3

Hershey and Chase used _____ to radioactively label the T2 phage's proteins. 32P 14C 92U 35S 222Ra

35S

Nucleic acids are assembled in the _____ direction. 2' to 3' 1' to 5' 5' to 3' 4' to 5' 5' to 1'

5' to 3'

When one DNA molecule is copied to make two DNA molecules, the new DNA contains 75% of the parent DNA. none of the parent DNA. 50% of the parent DNA. 100% of the parent DNA

50% of the parent DNA.

The envelope of a mumps virus A. helps the virus enter the cell B. is coded by viral genes C. helps the virus insert its DNA into the host cell genome D. accounts for viral resistance to antibiotics

A. helps the virus enter the cell

Who formulated the one gene-one enzyme hypothesis? Hershey and Chase Watson and Crick Mendel Beadle and Tatum

Beadle and Tatum

HIV does the greatest damage to A.) nervous tissue B.) pancreatic cells C.) white blood cells E.) the adrenal glands

C.) white blood cells

What is the transcription product of the sequence GCTAGCGATGAC? CAGTAGCGATCG CGTUCGCUTCUG CGAUCGCUACUG CGUTCGCUTCUG

CGAUCGCUACUG

The radioactive isotope 32P labels the T2 phage's _____. base plate head tail DNA protein coat

DNA

Which of these is a difference between a DNA and an RNA molecule? DNA is double-stranded, whereas RNA is single-stranded. DNA contains nitrogenous bases, whereas RNA contains phosphate groups. DNA contains uracil, whereas RNA contains thymine. DNA is a polymer composed of nucleotides, whereas RNA is a polymer composed of nucleic acids. DNA contains five-carbon sugars, whereas RNA contains six-carbon sugars.

DNA is double-stranded, whereas RNA is single-stranded.

What enzyme joins DNA fragments? DNA polymerase primase topoisomerase DNA ligase

DNA ligase

Two new strands of DNA molecules grow as bases are added by the enzyme _____. DNA polymerase bacterial duplicating complex DNA replicase RNA polymerase

DNA polymerase

Which of the following enzymes catalyzes the elongation of a new DNA strand? DNA polymerase single-stranded binding protein ligase helicase

DNA polymerase

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? DNA polymerase can assemble DNA only in the 3' to 5' direction the replication forks block the formation of longer strands it is more efficient than assembling complete new strands DNA polymerase can assemble DNA only in the 5' to 3' direction only short DNA sequences can extend off the RNA primers

DNA polymerase can assemble DNA only in the 5' to 3' direction

Which of the following occurs during DNA replication? DNA polymerase forms daughter molecules. Ligase then links these molecules together at their 5′ ends, forming the new daughter strand. DNA polymerase replicates the molecule 3′ to 5′ using the original strand as a template to form the new daughter molecule. DNA polymerase elongates the daughter strand, adding new nucleotides to the 3′ end of the molecule. The molecule grows 5′ to 3′ but is therefore read 3′ to 5′. DNA ligase replicates the new strand. DNA polymerase then proofreads the strand and makes any necessary corrections.

DNA polymerase elongates the daughter strand, adding new nucleotides to the 3′ end of the molecule. The molecule grows 5′ to 3′ but is therefore read 3′ to 5′.

Which of the following statements regarding DNA is false? DNA uses the sugar deoxyribose. DNA molecules have a sugar-phosphate backbone. One DNA molecule can include four different nucleotides in its structure. DNA uses the nitrogenous base uracil.

DNA uses the nitrogenous base uracil.

Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular component? protein → RNA → DNA DNA → tRNA → mRNA → protein DNA → RNA → protein RNA → DNA → RNA → protein

DNA → RNA → protein

A gene is usually __________. B). the same thing as a chromosome C). made of RNA D). made by a ribosome E). the information for making a polypeptide

E). the information for making a polypeptide

Which of these is classified as an emerging virus that can have a direct impact on human health? pneumonia tobacco mosaic virus Ebola lambda

Ebola

Frederick Griffith was one of the leading scientists looking at the genetic role of DNA. He was working on two strains of Streptococcus pneumoniae: The rough strain (R) did not cause pneumonia, but the smooth strain (S) did. When Griffith heat-killed the S strain and gave both the heat-killed S strain and the R strain to mice, the mice developed pneumonia and died. What happened in this experiment that caused the mice to develop pneumonia? The immune systems of the mice were unable to cope with both the S and R strains simultaneously. The R strain mutated and thus was able to cause pneumonia. Even though the S strain had been heat-killed, it changed the R strain. There was more of the R strain added than previously.

Even though the S strain had been heat-killed, it changed the R strain.

Which of the following statements about eukaryotic RNA is true? Introns are added to the RNA. The modified RNA molecule is transported into the nucleus. A small cap of extra nucleotides is added to both ends of the RNA. Exons are spliced together.

Exons are spliced together.

If one strand of DNA is CGGTAC, then the corresponding strand would be GCCTAG. GCCATG. GCCAUC. TAACGT.

GCCATG.

Which of the following statements about herpesviruses is false? Herpesviruses may cause cold sores or genital sores to appear during times of physical or emotional stress. Herpesviruses reproduce inside the host cell's mitochondria. Herpesviruses acquire their envelopes from the host cell nuclear membrane. Herpesviruses may remain dormant for long periods of time while inside the host cell nucleus.

Herpesviruses reproduce inside the host cell's mitochondria.

Which of the following people conducted the experiments that demonstrated that DNA is the genetic material of bacteriophages? Watson and Crick Pauling Franklin Hershey and Chase

Hershey and Chase

Who demonstrated that DNA is the genetic material of the T2 phage? Watson and Crick Darwin and Wallace Franklin Hershey and Chase Meselson and Stahl

Hershey and Chase

What is the function of reverse transcriptase? It catalyzes the formation of a polypeptide from an RNA template. It catalyzes the formation of DNA from a polypeptide template. It catalyzes the formation of RNA from a polypeptide template. It catalyzes the formation of RNA from a DNA template. It catalyzes the formation of DNA from an RNA template.

It catalyzes the formation of DNA from an RNA template.

Which of the following is true about double-stranded DNA? Adenine and uracil are present in equal amounts. It is shaped like a triple helix. The two strands are identical. Its strands have a sugar-phosphate backbone.

Its strands have a sugar-phosphate backbone.

Radiation is a frequent method of sterilization. It is effective because it causes damage to DNA. However, prions, the agents that cause diseases such as mad cow disease, are unaffected by these treatments because they lack DNA. What is the definition of a prion? Why? Prions are proteins folded into the correct configuration. Prions are small carbohydrate molecules that do not encode DNA. Prions are proteins that are folded incorrectly. Prions are small RNA molecules that do not encode proteins.

Prions are proteins that are folded incorrectly.

Prokaryotic organisms have a single origin of replication, whereas eukaryotic organisms have many origins where replication occurs simultaneously. Which of the following is the most probable reason for this observation? Prokaryotes do not replicate their DNA. Prokaryotic DNA is much smaller than eukaryotic DNA. Prokaryotic DNA is replicated more slowly than eukaryotic DNA. Prokaryotic DNA is single-stranded.

Prokaryotic DNA is much smaller than eukaryotic DNA.

Reverse transcription, carried out by retroviruses, is the process by which _____. DNA is duplicated RNA information is "read" to form a protein molecule DNA information is copied into RNA RNA information is copied into DNA

RNA information is copied into DNA

The synthesis of a new strand begins with the synthesis of a(n) _____. Okazaki fragment short pieces of DNA RNA primer complementary to a preexisting DNA strand single-strand binding protein poly(A) tail

RNA primer complementary to a preexisting DNA strand

Which of the following statements regarding RNA is false? RNA molecules have a sugar-phosphate backbone. One RNA molecule can include four different nucleotides in its structure. RNA uses the sugar dextrose. RNA uses the nitrogenous base uracil.

RNA uses the sugar dextrose.

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

Some HIV viruses have genetic variations in the RNA genome that provide resistance to the actions of the drug.

How would the shape of a DNA molecule change if adenine paired with guanine and cytosine paired with thymine? The DNA molecule would be longer. The DNA molecule would be circular. The DNA molecule would be shorter. The DNA molecule would have irregular widths along its length.

The DNA molecule would have irregular widths along its length.

Which of the following statements regarding a DNA double helix is true? The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amount of cytosine. The amount of adenine is equal to the amount of uracil, and the amount of guanine is equal to the amount of cytosine. The amount of adenine is equal to the amount of guanine, and the amount of thymine is equal to the amount of cytosine. The amount of adenine is equal to the amount of cytosine, and the amount of guanine is equal to the amount of thymine.

The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amount of cytosine.

Which of the following statements regarding the structure of DNA is false? In a DNA molecule, adenine bonds to thymine and guanine to cytosine. The sequence of nucleotides along the length of a single DNA strand is restricted by the base-pairing rules. Watson and Crick received a Nobel Prize for their description of the structure of DNA. The DNA molecule has a uniform diameter.

The sequence of nucleotides along the length of a single DNA strand is restricted by the base-pairing rules.

Which of the following statements is true about double-stranded DNA? It contains ionic bonds. Adenine and uracil are present in equal amounts. The strands run in opposite directions. The two strands are said to be identical.

The strands run in opposite directions.

A microbiologist analyzed chemicals obtained from an enveloped RNA virus—similar to a mumps virus—that infects monkeys. He found that the viral envelope contained a protein characteristic of monkey cells. Which of the following is the most likely explanation? The virus is a prophage. The virus forced the monkey cell to make proteins for its envelope. The virus gets an envelope that contains host molecules when it leaves the host cell. The virus fools its host by mimicking its proteins.

The virus gets an envelope that contains host molecules when it leaves the host cell.

Which of the following statements about plant viruses is false? The genetic material in most plant viruses is RNA. Once in a plant, a virus can spread from cell to cell through plasmodesmata. Preventing infections and breeding resistant plants can control viral infection in plants. There are many successful ways to rid infected plants of a virus.

There are many successful ways to rid infected plants of a virus.

Which of the following statements about treatment or prevention of a prion infection is true? There is no known treatment or cure for prion infections. Preventative vaccines have recently been shown to be effective in preventing prion infections. Antibiotic therapies such as penicillin are very effective cures. High doses of anti-inflammatory drugs such as ibuprofen reduce the symptoms of prion infections.

There is no known treatment or cure for prion infections.

How do retroviruses such as HIV differ from other viruses? They contain DNA that is used as a template to make RNA. They have much simpler reproductive cycles than other RNA viruses. They contain the enzyme reverse transcriptase. They can reproduce only inside living cells.

They contain the enzyme reverse transcriptase.

If Hershey and Chase had used radioactive oxygen in their experiments instead of phosphorus and sulfur, what results would they have likely obtained? They would have observed a radioactive signal in the pellet only. They would have observed a radioactive signal in the liquid only. They would have not observed radioactivity anywhere. They would have observed a radioactive signal in both the pellet and the liquid.

They would have observed a radioactive signal in both the pellet and the liquid.

In eukaryotes, translation is initiated only after transcription is completed. However, prokaryotes can initiate translation before a gene is completely transcribed. Which choice is the best explanation for this observation? Eukaryotic mRNA can be processed before ribosomes are moved into the nucleus to translate the protein. Ribosomes, which translate the proteins, are found only outside the nucleus in prokaryotes. Translation in eukaryotes cannot occur until the RNA leaves the nucleus, whereas in prokaryotes both transcription and translation occur in the cytoplasm. Prokaryotic mRNA needs to be extensively processed before it can be translated.

Translation in eukaryotes cannot occur until the RNA leaves the nucleus, whereas in prokaryotes both transcription and translation occur in the cytoplasm.

When messenger RNA (mRNA) is being transcribed, the RNA base _____ always pairs with the base _____ in DNA. T ... G U ... A A ... U U ... T

U ... A

Which of the following statements regarding viral diseases is false? AIDS was around for decades before becoming a widespread epidemic. RNA viruses tend to have an unusually high rate of mutation because their RNA genomes cannot be corrected by proofreading. New viral diseases often emerge when a virus infects a new host species. Very few new human diseases have originated in other animals because the genetic differences are too great.

Very few new human diseases have originated in other animals because the genetic differences are too great.

Which of the following techniques were most helpful to Watson and Crick in determining the structure of DNA? radioactive labeling X-ray crystallography cloned DNA electrophoresis

X-ray crystallography

The way that genetic material of a bacteriophage enters a bacterium is most like the way that water soaks into a sponge. skin lotion is rubbed onto the hands. a drug is injected with a hypodermic needle. a person swallows a pill.

a drug is injected with a hypodermic needle.

Which of the following describes a complete nucleotide? a sugar and a phosphate group a nitrogenous base and a sugar a nitrogenous base, a sugar, and a phosphate group a sugar and a pyrimidine or purine

a nitrogenous base, a sugar, and a phosphate group

What kind of virus is HIV? a retrovirus a complex virus a provirus a paramyxovirus

a retrovirus

The shape of a DNA molecule is most like a set of railroad tracks. a twisted rope ladder. a wooden ladder. beads on a string.

a twisted rope ladder.

Emerging viruses that infect human cells can originate from __________. lack of hygiene a virus spreading from one host species to humans a rapidly mutating lytic phage lambda viruses that were previously confined to bacterial populations that can now spread due to technological changes

a virus spreading from one host species to humans

The four bases contained in DNA are _____. adenine, guanine, uracil, thymine cytosine, guanine, thymine, uracil adenine, guanine, purine, thymine adenine, guanine, cytosine, thymine

adenine, guanine, cytosine, thymine

Which of the following is found in RNA but not in DNA? a covalently bonded backbone two purines and two pyrimidines an additional hydroxyl group four different nucleotides

an additional hydroxyl group

Why does a DNA strand grow only in the 5' to 3' direction? because DNA polymerase requires the addition of a starter nucleotide at the 5' end because DNA polymerases can only add nucleotides to the 3' end of the growing molecule because DNA polymerases can only add nucleotides to the 5' end of the growing molecule because the DNA molecule only unwinds in the 5' to 3' direction

because DNA polymerases can only add nucleotides to the 3' end of the growing molecule

During the replication of DNA molecules, __________. the cell undergoes mitosis both strands of the parent molecule act as templates only one strand of the parent molecule acts as a template errors never occur

both strands of the parent molecule act as templates

How do viroids harm the plants that are infected with them? by increasing the plants' metabolic rate by reducing the plants' seed production by altering the plants' growth by destroying the root system

by altering the plants' growth

The most likely method by which the mutated CCR5 gene prevents AIDS is by rupturing the nuclear membrane. attacking and destroying the HIV virus particles. coding for a protective protein in the cell membrane. covering the cell membrane.

coding for a protective protein in the cell membrane.

After DNA replication is completed, _____. there are four double helices one DNA double helix consists of two old strands and one DNA double helix consists of two new strands each new DNA double helix consists of two new strands each of the four DNA strands consists of some old strand parts and some new strand parts each new DNA double helix consists of one old DNA strand and one new DNA strand

each new DNA double helix consists of one old DNA strand and one new DNA strand

during DNA replication, _____. one daughter molecule ends up with two newly synthesized DNA strands four identical DNA molecules are produced each parental strand serves as a template for the synthesis of a complementary strand replication begins at one end of the chromosome and continues all the way to the other end

each parental strand serves as a template for the synthesis of a complementary strand

The 2009 H1N1 flu virus evolved through the genetic reshuffling of viruses that infect humans, birds, and pigs. killed over 50 million people worldwide. was spread by mosquitoes. was an avian flu virus.

evolved through the genetic reshuffling of viruses that infect humans, birds, and pigs.

We would expect that a 15-nucleotide sequence that includes a stop codon at the end (as part of the 15-nucleotide sequence) will direct the production of a polypeptide that consists of two amino acids. five amino acids. four amino acids. three amino acids.

four amino acids.

The first step in the replication of DNA is catalyzed by _____. ligase helicase DNA polymerase primase single-strand binding protein

helicase

What is the source of a viral envelope? host cell DNA prophages provirus host cell membrane viral glycoproteins

host cell membrane

The two strands of a DNA molecule are joined to each other through _____. hydrogen bonds between nucleotide bases ionic bonds between guanine and cytosine covalent bonds between carbon atoms in deoxyribose molecules covalent bonds between nitrogen atoms in adenine and in thymine

hydrogen bonds between nucleotide bases

Where do transcription and translation occur in prokaryotic cells? on the plasma membrane in the cytoplasm in chromatophores in the nucleus

in the cytoplasm

The drug AZT was one of the first drugs used to treat HIV. Which of the following drug actions would prevent the spread of HIV without harming the host cell? inhibition of reverse transcriptase inhibition of DNA polymerase destruction of amino acids that are vital to viral protein synthesis prevention of the formation of glycoproteins

inhibition of reverse transcriptase

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which demonstrated that _____ is the phage's genetic material. labeled DNA ... labeled protein labeled protein .... protein labeled DNA .... protein labeled protein ... DNA labeled DNA ... DNA

labeled DNA ... DNA

Short segments of newly synthesized DNA are joined into a continuous strand by _____. ligase single-strand binding protein helicase DNA polymerase primase

ligase

In the genetic code, some codons specify more than one amino acid. many amino acids are specified by more than one codon. some codons consist of two nucleotides. some amino acids are not specified by any codons.

many amino acids are specified by more than one codon.

Monomers for the synthesis of DNA are called __________. fatty acids nitrogenous bases nucleotides amino acids

nucleotides

The monomers of DNA and RNA are nucleotides. nucleic acids. monosaccharides. fatty acids.

nucleotides.

A uracil nucleotide is a __________ nitrogenous base attached to the __________, with the 5′ carbon of the sugar attached to a phosphate group. one-ringed : carbon of a sugar that has an H group at the 2′ carbon one-ringed : carbon of a sugar that has an OH group at the 2′ carbon two-ringed : carbon of a sugar that has an H group at the 2′ carbon one-ringed : carbon of a sugar that has only an OH group at the 3′ carbon

one-ringed : carbon of a sugar that has an OH group at the 2′ carbon

When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm? only the RNA the protein "headpiece" and its enclosed nucleic acid the whole phage only the DNA

only the DNA

One type of virus that infects bacteria is called a phage. rhinovirus. retrovirus. coronavirus.

phage.

Double-stranded viral DNA is incorporated into a host cell as a _____. promoter provirus transposon lac homeoboxes

provirus

The action of helicase creates _____. primers and replication bubbles primers and DNA fragments replication forks and replication bubbles DNA fragments and replication forks DNA fragments and replication bubbles

replication forks and replication bubbles

Which of the following enzymes does HIV use to synthesize DNA on an RNA template? RNA polymerase ligase DNA convertase reverse transcriptase

reverse transcriptase

During replication, the original "parent" DNA _____. is converted to RNA is incorporated into the new DNA strand is broken down as a new DNA strand forms serves as the template for the creation of two complete sets of DNA

serves as the template for the creation of two complete sets of DNA

Multiple origins of replication on the DNA molecules of eukaryotic cells serve to shorten the time necessary for DNA replication. create multiple copies of the DNA molecule at the same time. assure the correct orientation of the two strands in the newly growing double helix. remove errors in DNA replication.

shorten the time necessary for DNA replication.

The genetic material of HIV consists of _____. single-stranded DNA single-stranded RNA double-stranded DNA double-stranded RNA

single-stranded RNA

Viroids are _____ molecules and are found in _____. small circular DNA ... potatoes and other vegetables small circular RNA ... potatoes and other vegetables small linear DNA ... humans and other primates small linear DNA ... E.coli and other bacteria

small circular RNA ... potatoes and other vegetables

You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide because you see a _____. double-stranded molecule, not a single-stranded molecule phosphate group, not a uracil uracil nitrogenous base, not a thymine nitrogenous base thymine nitrogenous base, not a uracil nitrogenous base sugar with two, and not three, oxygen atoms

sugar with two, and not three, oxygen atoms

Hershey and Chase were able to differentiate between proteins and nucleic acids using radioactive atoms of elements found only in those macromolecules. Which of the following would be found only in proteins? hydrogen phosphorus carbon sulfur

sulfur

The copying mechanism of DNA is most like carving a figure out of wood. taking a picture of yourself and of your reflection in a mirror. dripping water out of a faucet. mixing flour, sugar, and water to make bread dough.

taking a picture of yourself and of your reflection in a mirror.

An old DNA strand is used as a _____ for the assembly of a new DNA strand. primer template complement model source of nucleotides

template

The "one gene-one polypeptide" theory states that the synthesis of each enzyme is catalyzed by one specific gene. the function of an individual gene is to dictate the production of a specific polypeptide. the function of each polypeptide is to regulate the synthesis of each corresponding gene. the synthesis of each gene is catalyzed by one specific enzyme.

the function of an individual gene is to dictate the production of a specific polypeptide.

In an important experiment, radioactively labeled bacteriophages were allowed to infect bacteria. In the first trial, the phages contained radioactive DNA, and radioactivity was detected in the bacteria. Next, other phages containing radioactive protein were allowed to infect bacteria, and radioactivity was not detected in the bacteria. These experiments led to the conclusion that _____. genes carry information for making proteins the genes of this phage were made of DNA bacteriophages can infect bacteria DNA is made of nucleotides

the genes of this phage were made of DNA

The information carried by a DNA molecule is in _____. the sugars and phosphates forming its backbone its amino acid sequence the total number of nucleotides it contains the order of the nucleotides in the molecule

the order of the nucleotides in the molecule

If you analyzed the nucleotide content of DNA, you would expect to find that __________. A + T = G + C the ratio of A to G is close to 1:1 and the ratio of T to C is close to 1:1 the ratio of A to T is close to 1:1 and the ratio of G to C is close to 1:1 the ratio of A to C is close to 1:1 and the ratio of G to T is close to 1:1

the ratio of A to T is close to 1:1 and the ratio of G to C is close to 1:1

Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids) are two-nucleotide sequences. nucleotide sequences of various lengths. three-nucleotide sequences. single nucleotides.

three-nucleotide sequences.

Which of these nitrogenous bases is found in DNA but not in RNA? guanine cytosine thymine uracil adenine

thymine

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand. guanine ... adenine cytosine ... uracil uracil ... cytosine thymine ... cytosine cytosine ... thymine

thymine ... cytosine

Viral DNA makes mRNA by the process of _____. replication infection translation lysis transcription

transcription

The transfer of genetic information from DNA to RNA is called elongation. transcription. initiation. translation.

transcription.

Life on Mars is finally discovered and a new organism that has six different nucleotides that encode 30 different amino acids is found on this planet. Which of the following nucleotide combinations would encode the minimum number of amino acids needed in this organism? four-nucleotide sequence (64 combinations) two-nucleotide sequence (62 combinations) one-nucleotide sequence (61 combinations) three-nucleotide sequence (63 combinations)

two-nucleotide sequence (62 combinations)

Which of the following is only associated with RNA? thymine adenine uracil deoxyribose

uracil

DNA replication results in the formation of four new DNA strands. uses each strand of a DNA molecule as a template for the creation of a new strand. occurs through the addition of nucleotides to the end of the parental DNA molecule. begins when two DNA molecules join together to exchange segments.

uses each strand of a DNA molecule as a template for the creation of a new strand.

Which of the following shows the steps of a viral infection in the proper order? virus locates host cell → enters nucleus → alters host cell DNA → destroys cell membrane virus locates host cell → forms hydrogen bonds → changes DNA to RNA→ host cell produces copies of virus virus locates host cell → penetrates cell membrane → enters nucleus → alters host cell DNA → host cell produces copies of virus virus locates host cell → alters host cell DNA → host cell produces copies of virus → copies enter host cell nucleus → nucleus leaves cell

virus locates host cell → penetrates cell membrane → enters nucleus → alters host cell DNA → host cell produces copies of virus

Hershey and Chase's experiment allowed them to discern whether DNA or proteins contain genetic information because __________. viruses consist only of proteins and DNA and only the DNA was injected into the host cells they could grow the viruses in culture media the enzymes used in host cell replication are identical to those used in phage replication the host cells became radioactive

viruses consist only of proteins and DNA and only the DNA was injected into the host cells