5 Written questions
5 Matching questions
- 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.
If scientists are trying to use what they know about HSV to devise a means of protecting other people from being infected, which of the following would have the best chance of lowering the number of new cases of infection?
A) medication that destroys surface HSV before it gets to neurons
B) interference with new viral replication in preexisting cases
C) vaccination of all persons with preexisting cases
D) education about avoiding sources of infection
E) treatment of the HSV lesions to shorten the breakout
- Which of the following accounts for someone who has had a herpesvirus-mediated cold sore or genital sore getting flare-ups for the rest of his or her life?
A) re-infection by the same herpes virus strain
B) copies of the herpes virus genome permanently maintained in host cell cytoplasm
C) re-infection by a closely related herpes virus of a different strain
D) copies of the herpes virus genome permanently maintained in host nuclei
E) co-infection with an unrelated virus that causes the same symptoms
- DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper?
A) to attach the DNA fragments to a permanent substrate
B) to prepare the DNA for digestion with restriction enzymes
C) to separate the two complementary DNA strands
D) to separate out the PCRs
E) to transfer only the DNA that is of interest
- DNA microarrays have made a huge impact on genomic studies because they
A) dramatically enhance the efficiency of restriction enzymes.
B) can be used to eliminate the function of any gene in the genome. C) allow the expression of many or even all of the genes in the genome to be compared at
D) allow physical maps of the genome to be assembled in a very short time.
E) can be used to introduce entire genomes into bacterial cells.
- The fact that plants can be cloned from somatic cells demonstrates that
A) differentiated cells retain all the genes of the zygote.
B) differentiated cells contain masked mRNA.
C) differentiation does not occur in plants.
D) genes are lost during differentiation.
E) the differentiated state is normally very unstable.
- a A) differentiated cells retain all the genes of the zygote
- b D) copies of the herpes virus genome permanently maintained in host nuclei
- c A) to attach the DNA fragments to a permanent substrate
- d B) interference with new viral replication in preexisting cases
- e C) allow the expression of many or even all of the genes in the genome to be compared at once
5 Multiple choice questions
- C) mutation of existing viruses, the spread of existing viruses to new host species, and the spread of existing viruses more widely within their host species
- A) to decrease the production from a harmful gain-of-function mutated gene
- B) the amino acid acts as a corepressor
- A) Eukaryotic exons may be spliced in alternative patterns
- C) by adding methyl groups to adenines and cytosines
5 True/False questions
In order to identify a specific restriction fragment using a probe, what must be done?
A) The fragments must be separated by electrophoresis.
B) The fragments must be separated by electrophoresis, the fragments must be treated with heat or chemicals to separate the strands of the double helix, and the probe must be hybridized with the fragment.
C) The fragments must be treated with heat or chemicals to separate the strands of the double helix.
D) The probe must be hybridized with the fragment.
E) The fragments must be separated by electrophoresis and the fragments must be treated
with heat or chemicals to separate the strands of the double helix. → D) single nucleotide polymorphisms found only in persons with a particular disorder
Which of the following can be effective in preventing the onset of viral infection in humans?
A) applying antiseptics
B) getting vaccinated
C) taking nucleoside analogs that inhibit transcription
D) taking vitamins
E) taking antibiotics → B) getting vaccinated
RNA viruses require their own supply of certain enzymes because A) these enzymes translate viral mRNA into proteins.
B) host cells rapidly destroy the viruses.
C) these enzymes cannot be made in host cells.
D) host cells lack enzymes that can replicate the viral genome.
E) these enzymes penetrate host cell membranes. → C) it uses viral RNA as a template for DNA synthesis
During DNA replication,
A) methylation of the DNA is maintained because DNA polymerase directly incorporates
methylated nucleotides into the new strand opposite any methylated nucleotides in the
B) methylation of the DNA is maintained because methylation enzymes act at DNA sites
where one strand is already methylated and thus correctly methylates daughter strands
C) methylated DNA is copied in the cytoplasm, and unmethylated DNA is copied in the
D) DNA polymerase is blocked by methyl groups, and methylated regions of the genome are
therefore left uncopied.
E) all methylation of the DNA is lost at the first round of replication. → B) methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication
In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to
A) the attachment of methyl groups to cytosine following birth, which changes the type of hemoglobin produced.
B) pseudogenes, which interfere with gene expression in adults.
C) histone proteins changing shape during embryonic development.
D) identical genes that generate many copies of the ribosomes needed for fetal globin production.
E) nonidentical genes that produce different versions of globins during development. → E) nonidentical genes that produce different versions of globins during development