Answer to Question 1
Earth's atmosphere formed as hot gases escaped from deep within the planet. This early atmosphere included gases such as carbon dioxide, methane, and ammonia (note that molecular oxygen was absent in the atmosphere until about 2.2 billion years ago). Experiments have shown that organic molecules necessary for life could have formed as the dissolved compounds in the atmosphere were exposed to light, heat, and electrical sparks. These energized mixtures can produce simple sugars and amino acids, proteins and nucleotides-all biologically important molecules.
Answer to Question 2
True
wild discuss fish
Evolution of Nervous Systems
Molecular tree of life
Polyps, or abnormal growths, on the lining of the large intestine may indicate early stages of colon
Earth Atmosphere
Animated The one-way flow of energy and cycling of materials in the world of life