35.All life Earth based carbon chemistry.36.The DNA molecules contain six : 1777283
35.All life on Earth is based on carbon chemistry.
36.The DNA molecules contain six different bases.
37.DNA molecules cannot be altered by chance errors in reproduction.
38.The oldest fossils on Earth are more than 3 billion years old.
39.The Miller experiment created synthetic DNA.
40.Chemical evolution concentrated the various smaller molecules into the more stable forms.
41.The Viking spacecraft searched for life on Mars by looking for the effects of life on the upper atmosphere.
42.If life is to develop on a planet, the planet must lie well inside the inner edge of its star's habitable zone.
43.The wavelengths that are most likely for communication with other civilizations are those in the water hole.
44.Even if societies on stars in distant galaxies survive at a technological level for only 10 years, that is long enough to establish two-way communication with them.