#1. Another name for unicellular organisms that dominated Earth up to the Precambrian time is A. eukaryotes. B. cyanobacteria. C. stromatolites. D. prokaryotes. #2. The greenhouse effect is related to the phenomenon of an increase in average surface temperature known as A. air pollution. B. agricultural improvement. C. global warming. D. conservation. #3. Which colorless and odorless gas, produced by radioactive decay of Uranium-238, is considered to be a cancer-causing agent? A. Oxygen B. Hydrogen C. Boron D. Radon.#4. Scientists can determine if oxygen existed in Earth's Archean atmosphere by A. determining how many people survived. B. looking for oxidized iron in rocks. C. looking at the amount of salt content in rocks. D. determining the lack of oxidation that occurred.
The correct answer for question number 1 is A - eukaryotes are the name
for unicellular organisms that dominated earth up to the Precambrian
times.
The correct answer for question number 2 is C - the
greenhouse effect is related to the phenomenon of an increase in average
surface temperature known as global warming.
The correct
answer for question number 3 is D - the colourless and odourless gas
that is produced by the radioactive decay of Uranium-238 and is considered
to be a cancer-causing agent is Radon.
The correct answer for
question number 4 is B - Scientists can determine if oxygen existed in
Earth's Archean atmosphere by looking for oxidized iron in rocks.
