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
The life cycle of the genus Pinus
Photosynthetic Organisms Changed Earth's Atmosphere
The tenuous atmosphere of Mars, visible on the horizon in this low-orbit photo
Polyps, or abnormal growths, on the lining of the large intestine may indicate early stages of colon
evolution
Early growth of corn (Zea mays), a typical monocot.