IB BIO HL UNIT 1

Unit 1 flashcards

Describe the conditions of early earth 🪨🔥➡🧊💨

4.3 billion years ago. Molten rock surface. Hadean eon. When the earth cooled, gases released from volcanic activity formed the earth’s atmosphere.

Identify the conditions of pre-biotic earth’s atmosphere

Ammonia, nitrogen, methane*, water*, very high levels of carbon dioxide, no free oxygen (anoxic), very high UV light levels

*=greenhouse gas

Describe the conditions of today’s atmosphere🌿⏎

high levels of oxygen, ozone layer (interaction bw UV light and oxygen), nitrogen. very small amounts of carbon dioxide, water vapor, ammonia, and methane.

Organic compounds

make up cells. have carbon. can form up to 4 covalent bonds

how could have organic compounds been created on early earth?

if energy was added to the gases. bc lack of oxygen, no ozone layer and higher UV penetration. higher concentrations of methan and CO2 made higher temps too.

Primordial soup

proposed by alexander oparin in 1924 and JBS Haldane in 1929.