(A) discuss viral mechanisms and possible ways of circumventing certain kinds of those mechanisms
(B) challenge recent research on how rhinoviruses bind to receptors on the surfaces of cells
(C) suggest future research on rhinoviral growth in chimpanzees
(D) defend a controversial research program whose purpose is to discover the molecular structure of rhinovirus capsids
(E) evaluate a dispute between advocates of two theories about the rhinovirus life cycle
22. 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”
(B) outside of the “canyon”
(C) responsible for producing nucleic acid
(D) responsible for preventing the formation of delta-receptors
(E) preventing the capsid from releasing its nucleic acid
23. 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
24. Which 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 in humans and mice
(C) Continuing to look for similarities among the various strains of rhinovirus
(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
25. It 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
(E) rhinoviruses are vulnerable to human antibodies
26. According to the passage, Rossman’s research suggests that
(A) a defense against rhinoviruses might exploit structural similarities among the strains of rhinovirus
(B) human cells normally do not develop antibodies to components of their own cells
(C) the various strains of rhinovirus differ in their ability to bind to the surface of a host cell
(D) rhinovirus versatility can work to the benefit of researchers trying to find a useful antibody
(E) Colonno’s research findings are probably invalid
27. According 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.
(B) The antibody must be specific to the molecular structure of the particular capsid.
(C) The capsid must separate from its nucleic acid before binding to an antibody.
(D) The antibody must bind to a particular cell-surface receptor before it can bind to a rhinovirus.
(E) The antibody must first enter a cell containing the particular rhinovirus.
