Which of the following molecules is thought to have arisen first during evolution?
(a) protein
(b) DNA
(c) RNA
(d) all came to be at the same time
(c) Because RNA is known to catalyze reactions within the cell, because the components of RNA are thought to be more readily formed in the conditions on primitive Earth, and because RNA can contain genetic information, it is the most likely of the three molecules to have arisen first in evolution.
You might also like to view...
What is the function of gastric inhibitory peptide?
a. reduces salivary secretions in the mouth b. stops contractions of the stomach c. slows peristalsis in the intestine d. prevents bile secretion by the liver
Which of the following quantities of alcoholic
beverages have the least damaging effect on the liver? a. a bottle of beer b. a glass of wine c. a shot of vodka d. either a bottle of beer or a glass of wine e. all have the same amount of ethanol and therefore have similar effects on the liver
In the Northern Hemisphere, when does the summer solstice occur?
A) when the sun reaches its northern maximum B) when the South Pole is closest to the sun C) when solar irradiance is at its minimum D) when lengths of day and night are equal at all latitudes
Both alcohol fermentation and lactate fermentation are highly ____ because the fuel is only partially ____
a. efficient; reduced b. efficient; oxidized c. inefficient; reduced d. inefficient; oxidized e. efficient; metabolized