AP Bio Chapter 19, 20, 21 Test

b

Viruses _____.

a. manufacture their own ATP, proteins, and nucleic acids

b. use the host cell to copy themselves and make viral proteins

c. use the host cell to copy themselves and then viruses synthesize their own proteins

d. metabolize food and produce their own ATP

c

What is the main structural difference between enveloped and nonenveloped viruses?

a. enveloped viruses have their genetic material enclosed by a layer made only of protein

b. nonenveloped viruses have only a phospholipid membrane, while enveloped viruses have two membranes, the other one being a protein capsid

c. enveloped viruses have a phospholipid membrane outside their capsid whereas nonenveloped viruses don't have a phospholipid membrane

d. both types of viruses have a capsid and phospholipid membrane; but in the nonenveloped virus the genetic material is b/t these two membranes, while in the enveloped virus the genetic material is inside both membranes

d

The host range of a virus is determined by

a. the enzymes carried by the virus

b. whether its nucleic acid is DNA or RNA

c. the proteins in the host's cytoplasm

d. the proteins on its surface and that of the host

c

Which of the following is characteristic of the lytic cycle?

a. Viral DNA is incorporated into the host genome.

b. The viral genome replicates without destroying the host.

c. A large number of phages are released at a time.

d. The virus—host relationship usually lasts for generations.

a

What is the function of reverse transcriptase in retroviruses?

a. it uses viral RNA as a template for DNA synthesis

b. it converts host cell RNA into viral DNA

c. it translates viral RNA into proteins

d. it uses viral RNA as a template

b

HIV is inactivated in the lab after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. What are the practical consequences of these findings?

a. HIV can be transmitted more easily from person to person than the flu virus

b. the flu virus can be transmitted more easily from person to person than HIV

c. this property of HIV makes it more likely to be a pandemic than the flu virus

d. disinfecting surfaces is more important to reduce the spread of HIV than the flu

a

Which of the following could use reverse transcriptase to transcribe its genome

a. ssRNA

b. dsRNA

c. ssDNA

d. dsDNA

b

Which of the following can be effective in preventing the onset of viral infection in humans?

a. taking vitamins

b. getting vaccinated

c. taking antibiotics

d. taking drugs that inhibit transcription

b

Which of the following represents a difference between viruses and viroids?

a. viruses infect many types of cells, whereas viroids infect only prokaryotic cells

b. viruses have capsids composed of protein, whereas viroids have no caspids

c. viruses have genomes composed of RNA, whereas viroids have genomes composed of DNA

d. viruses cannot pass through plasmodesmata, whereas viroids can

d

What are prions?

a. mobile segments of DNA

b. tiny circular molecules of RNA that can infect plants

c. viral DNA that attaches itself to the host genome and causes disease

d. misfolded versions of normal protein that can cause disease

c

In the figure, at the arrow marked II, what enzyme(s) are being utilized?

A) reverse transcriptase

B) viral DNA polymerase

C) host cell DNA polymerase

D) host cell RNA polymerase

d

In the figure, when new viruses are being assembled (IV), what mediates the assembly?

A) host cell chaperones

B) assembly proteins coded for by the host nucleus

C) assembly proteins coded for by the viral genes

D) nothing; they self-assemble

b

What is the difference between an epidemic and a pandemic?

a. an epidemic is a disease; a pandemic is a treatment

b. an epidemic is restricted to a local region; a pandemic is global

c. an epidemic has low mortality; a pandemic has higher mortality

d. an epidemic is caused by a bacterial infection; a pandemic is caused by a viral infection

d

The herpes viruses are very important enveloped DNA viruses that cause disease in all vertebrate species and in some invertebrates such as oysters. Some of the human ones are herpes simplex (HSV) I and II, causing facial and genital lesions, and the varicella-zoster (VSV), causing chicken pox and shingles. Each of these three actively infect nervous tissue. Primary infections are fairly mild, but the virus is not then cleared from the host; rather, viral genomes are maintained in cells in a latent phase. The virus can then reactivate, replicate again, and be infectious to others.

41) In electron micrographs of HSV infection, it can be seen that the intact virus initially reacts with cell surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsids go from being full to being "empty." Which of the following best fits these observations?

A) Viral capsids are needed for the cell to become infected; only the capsids enter the nucleus.

B) The viral envelope is not required for infectivity, since the envelope does not enter the nucleus.

C) Only the genetic material of the virus is involved in the cell's infectivity, and is injected like the genome of a phage.

D) The viral capsid mediates entry into the cell, and only the genomic DNA enters the nucleus, where it may or may not replicate.

a

Which of the following processes with in viral replication is the greatest source of genetic variation in RNA virus populations?

a. high mutation rate due to lack of proofreading of RNA genome replication errors

b. transcription form the host cell RNA polymerase introduces numerous mutations

c. capsid proteins from the host cell can replace the viral capsid

d. viral RNA is translated by host cell ribosomes

c

Cells were infected with approximately 1000 copies of either virus A or virus B at the 0 time

point. At five-minute intervals, a sample of the virus and cell mixture was removed. The intact

cells were removed from the sample, and the number of viruses per milliliter of culture was

determined.

18) Using the data in the figure above, how long does it take for virus A to go through one lytic

cycle?

A) 15 minutes

B) 30 minutes

C) 45 minutes

D) 90 minutes

d

Cells were infected with approximately 1000 copies of either virus A or virus B at the 0 time

point. At five-minute intervals, a sample of the virus and cell mixture was removed. The intact

cells were removed from the sample, and the number of viruses per milliliter of culture was

determined.

Using the data in the figure above, how long does it take for virus B to go through one lytic

cycle?

A) 15 minutes

B) 30 minutes

C) 45 minutes

D) 60 minutes

d

32) Which of the following series best reflects what we know about how the flu virus moves

between species?

A) The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who

eat the pig products can be infected.

B) A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus

differently and then pass it back to humans.

C) An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus;

this enables it to be transmitted to a human host.

D) An animal such as a pig is infected with more than one virus, genetic recombination occurs,

the new virus mutates and is passed to a new species such as a bird, the virus mutates and can be transmitted to humans.

C

You isolate an infectious substance capable of causing disease in plants, but you do not know

whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at

your disposal to analyze the substance and determine the nature of the infectious agent.

I. Treat the substance with enzymes that destroy all nucleic acids and then determine whether

the substance is still infectious.

II. Filter the substance to remove all elements smaller than what can be easily seen under a light

microscope.

III. Culture the substance on nutritive medium, away from any plant cells.

IV. Treat the sample with proteases that digest all proteins and then determining whether the

substance is still infectious.

40) If you already know that the infectious agent was either bacterial or viral, which method(s)

listed above would allow you to distinguish between these two possibilities?

A) I

B) II

C) II or III

D) IV

d

You isolate an infectious substance capable of causing disease in plants, but you do not know

whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at

your disposal to analyze the substance and determine the nature of the infectious agent.

I. Treat the substance with enzymes that destroy all nucleic acids and then determine whether

the substance is still infectious.

II. Filter the substance to remove all elements smaller than what can be easily seen under a light

microscope.

III. Culture the substance on nutritive medium, away from any plant cells.

IV. Treat the sample with proteases that digest all proteins and then determining whether the

substance is still infectious.

If you already know that the infectious agent was either a viroid or a prion, which method(s)

listed above would allow you to distinguish between these two possibilities?

A) I only

B) II only

C) IV only

D) either I or IV

b

What sequence is a palindrome?

A) 5' ATG 3'

B) 5' AGGCCT 3'

C) 5' CCATT 3'

D) 5' CCAGG 3'

a

The restriction enzyme HindIII cuts between the two adenines in the sequences 5' AAGCTT 3'. If HindIII were to recognize and cut this sequence is a strand of DNA, what would be the result?

a. sticky ends

b. blunt ends

c. ends 2 nucleotides long

d. a partial DNA cut

d

A research was attempting to make a transgenic corm plant by inserting a certain animal growth hormone gene into the genome of a corn plant. He used the restriction enzyme EcoRl to cut the corn DNA and HaeIII to cut the animal DNA. However, even after many attempts, the growth hormone gene would never insert into the corn DNA. What went wrong?

a. It is impossible to mix plant and animal DNA because their cell types are too different

b. the corn DNA needed to be cut with the HaeIII restriction enzyme, and the animal DNA needed to be cut with the EcoRl restriction enzyme

c. Restriction enzymes, which are harvested from bacteria that fight against bacteriophages, are only meant to cut viral DNA

d. Both the corn DNA and the animal DNA needs to be cut with the same restriction enzyme in order for the growth hormone gene to insert into the corn genome

a

The rate of migration of DNA within an agarose gel in the gel electrophoresis technique is primarily based on what factor?

A) The size of the DNA fragments

B) The number of DNA fragments

C) The size of the wells of the gel

D) The negative charge of the DNA

a

The creation of a DNA fingerprint involves all but which of the following techniques?

A) DNA Microarray

B) Restriction enzymes

C) Polymerase chain reaction

D) Gel electrophoresis

b

In the Sanger method of DNA sequencing, what causes the termination of chain elongation?

A) The incorporation of a deoxynucleoside triphophates (dNTPs)

B) The incorporation of a dideoxynucleotide triphosphate (ddNTPs)

C) Denaturation of the double-stranded test fragments

D) When the DNA polymerase encounters a stop codon

c

In sequential order, what are the three steps of PCR?

A. anneal primers, extend primers, denature DNA

B. denature DNA, extend primers, anneal primers

C. denature DNA, anneal primers, extend primers

D. extend primers, anneal primers, denature DNA

b

What biochemical limitation of DNA polymerase ensures that, among nucleotides in a genome, only a desired gene sequence surround by primers will be amplified during PCR?

a. DNA polymerase has the can only recognize start codons and begin replication there

b. DNA polymerase can only add nucleotides to a free 3' carbon, and therefore will only replicate the region surround be primers

c. DNA polymerase cannot copy an entire genome, it can only copy one gene at a time

d. DNA polymerase can only start DNA replication in the middle of the genome, around the centromere, which is where the desired genes are located

c

A student performed PCR using a DNA polymerase from human cells rather than the normal PCR polymerase that comes from a species of bacteria known as Thermus aquatics. At the end of the experiment the student realized that none of her desired gene had copied. Why?

a. Human DNA polymerase can only add deoxynucleoside triphosphate (dNTPs) during replication, but dideocynucleoside triphosphate (ddNTPs) are used during PCR.

b. Human DNA polymerase can only make one of a gene, but PCR requires millions of copies to be made

c. Human DNA polymerase denatures when the thermocycler is heated to 95°C

d. Human DNA polymerase only functions while inside intact human cells it will cease to function once it is removed

b

What is the source of the reverse transcriptase used in recombinant DNA technology?

a. Plant cells

b. Retroviruses

c. Cultured fungi cells

d. Phage-infected mammalian cells

b

Human nerve cells differ from human muscle cells because different sets of genes are expressed; in each type of cell, different genes are transcribed into mRNA and translated into protein. Which of the following techniques would be the most efficient way to identify the genes that these cells express?

a. Gel electrophoresis of DNA fragments

b. DNA microarray assays

c. Isolating and analyzing all proteins from each type of tissue

d. PCR

c

DNA microarrays have made a huge impact on genomic studies because they

A) can be used to eliminate the function of any gene in the genome.

B) can be used to introduce entire genomes into bacterial cells.

C) allow the expression of many or even all of the genes in the genome to be compared at once.

D) allow physical maps of the genome to be assembled in a very short time.

c

_____ can give rise to any type of cell whereas _____ can give rise to a subset of cell types.

A)Heterozygous cells ... homozygous cells

B)Adult stem cells ... embryonic stem cells

C)Embryonic stem cells ... adult stem cells

D) Adult stem cells ... totipotent cells

d

Dolly, the sheep, was cloned from an adult cell. She had a number of health problems and died at a relatively young age. Three mules that were born in 2003 were cloned from fetal cells. If it turns out that the mules remain healthy and live normal lives, how would this outcome tie in with Gurdon's observations with tadpoles?

A) No correlation between the age of the donor cells and the ability of the transplanted nucleus to direct development.

B) Nuclei from older donor cells were more likely to correctly direct differentiation and give rise to healthy tadpoles.

C) Positive correlation between the age of the donor nuclei and the ability of the nuclei to direct differentiation.

D) The ability of a transplanted nucleus to direct normal development was inversely related to the age of the donor.

c

Nuclear transplantation in cloning involves

a. inserting a sperm cell into an egg cell in vitro

b. placing the nucleus from an egg cell into an enucleated somatic cell

c. removing the nucleus of an egg and placing it with the nucleus of a somatic cell

d. the use of microarray analysis and RNA interference

a

Once an organism's genome sequence has been determined, how do scientists generally start identifying all the genes within the genome?

a. Analyze the sequence using software that scans the sequence for telltale sequence elements such as promoters,transcription start and stop sites, and so on.

b. Hybridize the DNA with probes specific for known genes from other organisms

c. Use DNA microarrays to examine the expression of huge numbers of sequences from the genome under different conditions

d. Individually mutate all of the nucleus within the genome, and determine which mutations cause a detectable phenotype

d

An example of a systems biology experiment might be _____.

a. comparing the insulin resistance gene in human, mouse, and chimpanzee genomes

b. determining what gene mutation causes insulin resistance

c. determining the normal biochemical function of the gene involved in insulin resistance

d. determining how insulin resistance affects transcription of thousand other genes.

c

Studies that determine gene annotation _____.

a. determine the frequencies of specific genes throughout the genome

b. use fluorescent RNA probes to determine the presence and location of a gene

c. identify which genes are protein-coding within a genome

d. simultaneously sequence the genomes of multiple species in an environmental sample

b

Which of the following statements concerning eukaryotic and prokaryotic genomes is not true?

a. Genomes of most bacteria and archaea range from 1 to 6 million base pairs (Mb)l genomes of eukaryotes are usually larger

b. The size of an organism's genome is directly correlated to its phenotype

c. Vertebrate genomes can produce more than one polypeptide per gene because of alternative splicing of RNA transcripts

d. Humans and other mammals have the lowest gene density, or number of genes, in a given length of DNA

b

Why might the number of genes in eukaryotic genomes underestimate the number of different proteins that an organism makes?

a. the genome rearranges its DNA so that different cells can make different cells can make different proteins

b. Many genes undergo alternative splicing, so that different proteins with different exon combinations are produced from the same gene.

c. organisms take up foreign DNA and make proteins encoded by these foreign DNA molecules

d. all of the listed responses are correct

c

What factor accounts most for the difference in genome size between vertebrates and prokaryotes?

a. Vertebrates have more genes for functional RNA molecules

b. Vertebrates have more protein-coding genes

c. Vertebrates have more noncoding DNA sequences

d. Vertebrates have longer and more complex upstream regulatory sequences

a

Segments of eukaryotic DNA that can move or be copied from one site to another in the genome are called

a. retrotransposons

b. introns

c. exons

d. transposons

b

The similarity of the homeobox in many different kinds of organisms is evidence ______.

a. of convergent evolution

b. of the common ancestry of different life-forms

c. that it is not responsive to natural selection

d. of its recent origin

b

What is a valid rationale for sequencing the chimpanzee genome?

a. to be able to study human diseases in chimpanzees

b. to determine what genetic changes determine uniquely human features such as large brains and language ability

c. to determine whether another human pathogen such as HIV could originate from viruses that infect chimpanzees

d. to determine whether any chimpanzee genes could be used to genetically engineer superior humans, or vice versa

b

A misaligned cross over between two homologous chromosomes usually results in

a. deletion in one chromosome and no change in the other.

b. deletion in one chromosome and a duplication in the other.

c. deletions in both chromosomes.

d. duplications in both chromosomes.

c

The genomes of higher eukaryotes contain families of closely related genes. Which of the following statements offers the best explanation for the origin of these gene families:

a. were acquired through horizontal gene transfer from closely related organisms

b. represent several rounds of whole-genome duplication

c. arose from multiple round of gene duplication with subsequent divergence

d. are the result of alternative processing patterns for intron and eons

d

The a-globin gene family includes 5 pseudogenes. What is pseudogene?

a. an unidentified gene located within a gene family

b. mobile genetic elements

c. a gene with the same sequence as another gene in the same organism

d. former genes that have accumulated mutations and are nonfunctional

c

What types of organism have been best studied using metagenomics?

a. large mammals

b. eukaryotic organisms

c. microorganisms

d. plants

a

Lysozyme and alpha-lactalbumin have similar amino acid sequences but different functions. The genes for both proteins are found in mammals, but birds have only the gene for lysozyme. What does this observation suggest about the evolution of these genes?

a. A close relative probably had the lysozyme gene, lineages split, the gene underwent duplication and mutation, and now mammals have a lysozyme gene and a closely related alpha-lactalbumin gene

b. As mammals evolved, their need for lysozyme decreased

c. The differences between mammals and birds is directly related to the introduction of an alpha-lactalbumin gene

d. none of the above

c

In 2005, Icelandic scientists rerouted finding a large chromosomal inversion present in 20% of northern Europeans, and they noted that Icelandic women with this inversion had significantly more children than women without it. What would you expect to happen to the frequency of this inversion in the Icelandic population in future generations

a. the inversion will eventually be filtered out of the human genome since it is an example of a mutation

b. the percentage of woman containing the chromosomal inversion will decrease

c. the invasion will be selected for and its frequency in a population will increase

d. the frequency will remain the same