epdf.pub_cbest-cliffs-test-prep13a9b242c7cb4125e6cca92d00a73d5a41681

Part II: Analysis of Exam Areas
production; that is, autoinducer could stimulate synthesis of the encoded proteins
and, thus, of light. Their theory met with skepticism at first but has since
been confirmed and expanded.
Read All the Choices to Look for the Best Answer
Sample
8. According to the passage, Nealson and Hasting’s research was instrumental
in indicating that
A. bacteria communicate through molecular messengers that travel
between cells.
B. luminous bacteria glow not at a constant density but at various densities.
C. bacteria are genetically coded by the autoinducer.
D. the molecular messenger luciferase causes bacteria to glow at high
densities.
E. the autoinducer, not the enzyme luciferase as was previously believed,
produces the luminosity of certain marine bacteria.
The best choice is A. Although the research focused on marine bacteria that glow,
its broader significance is that it shows the chemical communication between bacteria.
Choice B is the observation that led to the theory, but is not the best answer.
Choice C is inaccurate; an autoinducer does not code genes but induces their expression.
Choice D is also incorrect because the molecular messenger that causes
bacteria to glow is not the enzyme luciferase. Choice E might seem correct at first
reading, but although the autoinducer allows the expression of the light-producing
enzymes such as luciferase, it doesn’t produce light itself.
Know Where to Locate a Specific Detail in the Passage
Sample
9. Which of the following are characteristic of the autoinducer involved in
light production by marine bacteria?
I. It catalyzes chemical reactions in bacterial cells.
II.
III.
It stimulates synthesis of certain proteins.
It acts as a messenger between enzymes and bacteria.
20
A. I and II only
B. II and III only
C. II only
D. III only
E. I, II, and III