American scientists Stanley Miller and Harold Urey used an apparatus similar to the one in the diagram below to simulate how life could have formed on Earth. The apparatus contained hydrogen gas, water vapor, ammonia, and methane. These gases were subjected to a spark, to simulate lightning. They found that organic molecules could form from the inorganic gases. Their theory of how life began, however, did not hold up under further testing. What crucial fact did they not have when they conducted their experiment?

F. There was no lightning in Earth's early atmosphere.

G. Ammonia and methane were not in the early atmosphere.

H. The chemicals used in the experiment were contaminated.

I. Organic molecules already existed before the atmosphere formed.

Which of the following is the most likely result of converting forestland to urban development? a.the amount of land available for lumber production decreases. b.fewer trees are needed because cities are made mainly of concrete. c.people discover more efficient ways to grow trees. d. the price of lumber goes down.

How will technology impact medicine in the future?

Taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? view available hint(s)taq polymerase is an enzyme isolated from the organism thermophilus aquaticus. this organism has been found living in the hot springs of yellowstone national park. this enzyme is used to copy human dna from crime scenes. most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? the enzyme will not work on human dna.nothing should be altered.the ph should be decreased.the temperature should be raised.