The primary purpose of the passage is to (A) discuss viral mechanisms and possible ways of circumventing certain kinds of those mechanisms
Perfect - feels good when you get the correct answer as option A this is precisely what the passage does.(B) challenge recent research on how rhinoviruses bind to receptors on the surfaces of cells
Nothing challenged here.(C) suggest future research on rhinoviral growth in chimpanzees
no future research is suggested.(D) defend a controversial research program whose purpose is to discover the molecular structure of rhinovirus capsids
Vague options which are easy to discard ( if you need to do that at all given how glaringly obvious option A is)(E) evaluate a dispute between advocates of two theories about the rhinovirus life cycle
no dispute at all!Okay - sudden jump to the end of the passage - need to realize that the author suggests that common sequences of proteins occur at the base of a narrow canyon and are unreachable to the antibodies - so by implication the most varied ones are at the top - GREAT QUESTION!It can be inferred from the passage that the protein sequences of the capsid that vary most among strains of rhinovirus are those (A) at the base of the "canyon"
TRAP - coz it is verbatim from the passage and given the dearth of possible correct options one might fall for it (B) outside of the "canyon"
Perfect answer to an awesome question!(C) responsible for producing nucleic acid
palpably wrong(D) responsible for preventing the formation of delta-receptors
not quite there - delta receptors are on the cells and this is about the virus(E) preventing the capsid from releasing its nucleic acid
not quite - nothing in the virus prevents the release of the capsid as the survival of the virus depends on releasing the capsid once inside the host cellThe receptors to which the rhinovirus binds are delta receptors - so a cell without those could not be a host to the virus - simplest of the questions.It can be inferred from the passage that a cell lacking delta-receptors will be (A) unable to prevent the rhinoviral nucleic acid from shedding its capsid
(B) defenseless against most strains of rhinovirus
(C) unable to release the viral progeny it develops after infection
(D) protected from new infections by antibodies to the rhinovirus
(E) resistant to infection by most strains of rhinovirus
Perfect! For the reasons mentioned above - we are practically searching for this option.Other options are trivially wrong according to meNewer antibodies definitely is not the way forward according to the author - the first study described how mice became immune and also chimps became partially immune due to hindering the reception of the virus into host cell. Second study talked about non-antibody type cells preferably small enough to be able to enter the canyon to go and destroy the virus by binding to it and the final line of the passage is a clueWhich of the following research strategies for developing a defense against the common cold would the author be likely to find most promising?
(A) Continuing to look for a general antirhinoviral antibody
(B) Searching for common cell-surface receptors humans and mice
TRAP - related to the first experiment - but first experiment does not mention this.(C) Continuing to look for similarities among the various strains of rhinovirus
Perfect so that the small nonanti-body small sized cells can go into the canyon and help nip the problem in the bud(D) Discovering how the human body produces antibodies in response to a rhinoviral infection
(E) Determining the detailed molecular structure of the nucleic acid of a rhinovirus
Others trivially wrongdetail about first studyIt can be inferred from the passage that the purpose of Colonno's experiments was to determine whether (A) chimpanzees and humans can both be infected by rhinoviruses
(B) chimpanzees can produce antibodies to human cell-surface receptors
(C) a rhinovirus' nucleic acid might be locked in its protein coat
(D) binding antibodies to common receptors could produce a possible defense against rhinoviruses
if you cannot bind antibody to the virus - bind it to the common receptors of the cells - this is exactly what the first study does(E) rhinoviruses are vulnerable to human antibodies
They are not - that is why the cold is so common. Other options are easy to discard.second study about the base of canyon weakness in the virus' armorAccording to the passage, Rossman's research suggests that (A) a defense against rhinoviruses might exploit structural similarities among the strains of rhinovirus
Yup - this is a general way to put it.(B) human cells normally do not develop antibodies to components of their own cells
TRUE but irrelevant to the study(C) the various strains of rhinovirus differ in their ability to bind to the surface of a host cell
not true - all strains bind successfully and are structurally similar (with deep small canyon)(D) rhinovirus versatility can work to the benefit of researchers trying to find a useful antibody
We havve to work despite that - it does not benefit(E) Colonno's research findings are probably invalid
Blatantly wrongVague detail question but one that has been mentioned in the first studyAccording to the passage, in order for a given antibody to bind to a given rhinoviral capsid, which of the following must be true? (A) The capsid must have a deep "canyon" on each of its faces.
confusion and trap answer - this is with reference to the second study and this is not a helpful thing for antibody to bind but rather prevents it(B) The antibody must be specific to the molecular structure of the particular capsid.
Verbatim from the passage(C) The capsid must separate from its nucleic acid before binding to an antibody.
completely different thing - happens once the virus is inside the host(D) The antibody must bind to a particular cell-surface receptor before it can bind to a rhinovirus.
irrelevant - given the question, we are talking about binding to the virus(E) The antibody must first enter a cell containing the particular rhinovirus.
wrong!Hope these answers are helpful.