Origins of Organic Molecules on Primitive Earth

In the 1920s, Oparin and Haldane proposed that Earth's early atmosphere contained gases like nitrogen and methane, lacking oxygen until photosynthesis emerged. They suggested organic molecules could form with energy sources like lightning. In 1953, Miller and Urey tested this by simulating early Earth conditions, finding simple organic compounds. Their work showed that essential organic molecules could arise from primitive atmospheric gases with energy input.

What gases did Oparin and Haldane suggest were present in the early Earth's atmosphere?

• Carbon monoxide, nitrogen, and water vapor

• Hydrogen, helium, and oxygen

• Nitrogen, ammonia, and methane

• Oxygen, nitrogen, and carbon dioxide

Which energy sources were proposed to facilitate the formation of organic molecules on early Earth?

• Cosmic rays and solar winds

• Tidal forces and magnetic fields

• Electricity from storms and ultraviolet radiation

• Volcanic eruptions and earthquakes

What was the primary purpose of the Miller-Urey experiment?

• To study the effects of UV radiation on modern organisms

• To measure the atmospheric pressure of early Earth

• To simulate the conditions of early Earth and test the formation of organic molecules

• To determine the age of the Earth

What did Miller and Urey find in their experiment after one week?

• Minerals and salts

• Simple carbon compounds like formaldehyde and hydrogen cyanide

• Only water and gases

• Complex proteins and DNA

What types of organic compounds were synthesized in experiments following Miller and Urey's work?

• Simple sugars and lipids

• Vitamins and hormones

• Complex carbohydrates and nucleic acids

• Formic acid, urea, and amino acids

What did the experiments following Miller and Urey's work demonstrate about the formation of organic molecules?

• They could only form in the presence of oxygen

• They were impossible to form under any conditions

• They required the presence of living organisms

• They could form from primitive atmospheric gases with electrical energy