Earth's Early History (ch 20.3)

Denser materials formed the Earth's core while less dense materials formed the ______.

• Core

• Mantle

• Surface

• Atmosphere

The theory suggests that Earth cooled enough for water, composed of hydrogen and oxygen, to remain a ___ about _____ years ago.

• liquid and 4 billion

• solid and 2 billion

• gas and 4 billion

• liquid and 2 billion

• gas and 2 billion

The Miller & Urey experiment is an example of a scientific attempt to prove how ____ appeared

• first plants

• first organic molecules

• first eukaryotic cells

• first prokaryotic cells

Which of the following was a key component in the Miller & Urey experiment to simulate early Earth conditions providing energy for the molecules to combine

• Solar Panels

• Electrical Current

• Magnetic Field

• High Pressure

What was the significance of the amino acids found in the Miller & Urey experiment?

• They indicated the presence of life

• They showed the possibility of life forming from non-living materials

• They were used as fuel

• They were a byproduct of combustion

The earth and life began during the ___

• Paleozoic Era

• Mesozoic Era

• Cenozoic Era

• Precambrian

The first living cells are believed to be __

• anerobic bacteria living in a methane - ammonia environment

• aerobic bacteria living in a nitrogen - oxygen environment

• anerobic protists living in a methane - ammonia environment

• aerobic protist living in a nitrogen - oxygen environment

The first living cells are believed to be formed ___ although scientists are not sure how.

• 3.5 million years ago

• 2 billion years ago

• 4.6 billion years ago

• 3.5 billion years ago

What do scientists believed converted the atmosphere from methane - ammonia to the nitrogen - oxygen atmosphere we enjoy today.

• photosynthesis performed by plants and algae

• photosynthesis performed by bacteria

• earth cooling enough for water to remain in liquid form

• endosymbiosis

• primordial soup theory

The formation of the first eukaryotic cells is called ___

• photosynthesis performed by bacteria

• earth cooling enough for water to remain in liquid form

• endosymbiosis

• primordial soup theory