1. Which of the following would support Scientist 2’s view?
A.  Evidence of an increase of radiation & ultraviolet light reaching the earth.
B.  Fossils showing no mature plants & stunted growth—a sign of nuclear winter.
C.  A study showing that bacteria adjust poorly to changes in laboratory settings.
D.  Previous fossil record findings are erroneous.

    The correct answer was A; evidence of an increase in ultraviolet light and radiation would cause mutations in the various dinosaurs' genoms.  As a result of this, various variants of each dinosaur would exist and they would all fight for survival, evolving slowly.  Choice B is in support of Scientist 1's viewpoint so is incorrect.  Answer C is also incorrect because any studies of bacteria in laboratory conditions would take place over a short time span, evolutionary changes take place over eons of time.  The bacteria in the lab are simply reacting to a stimuli and are not changing their genetic makeup.  Erroneous fossil findings (D) would support the first scientist's viewpoints.

2. Which of the following is the best alternate explanation for the dinosaurs’ extinction?
A. Insects began to grow in increasing numbers.
B. Larger trees & vegetation became prevalent, inhibiting the movement of dinosaurs.
C. Small carnivores evolved to attack in packs and were able to overpower the dinosaurs.
D. Flora & fauna became parasitic and overran more traditional plants in aquatic environments.

    The correct answer here was C; of these choices the most direct change and harm for the dinosaurs would be small threatening packs of carnivores.

3. According to Scientist 1, iridium
A. Is commonly found in the earth’s crust.
B. Exists only on asteroids.
C. Can be bountifully found in the mentioned thin layer of clay.
D. Creates a catastrophic dust cloud which causes nuclear winter.

    From the passages, one will find that it is stipulated by both parties that a thin layer of clay contains iridium, so the correct choice is choice C.  The other statements were not mentioned by either party.

4. By the information provided, a layer of iridium
A. Occurs naturally.
B. Signifies catastrophe.
C. Would be unnatural for dinosaurs & would kill them all with radiation poisoning.
D. is rarely found in the earth's crust.

    Again, it seems to be universally accepted by both scientists that iridium is rarity in/on the earth's crust (choice D).

5. Which of the following would most support Scientist I’s viewpoint?
A. Evidence of tectonic plate shifting with volcanic activity.
B. Discovery of a huge 6-mile diameter crater in one of the earth’s oceans.
C. Research finding plants of the cretaceous period to thrive in low light.
D. Discovery of mutated dinosaur fossils.