Early Earth

Which event happened last during Earth's formation?

• Core formation

• Plantary cooling

• End of Heavy Bombardment

• Planetary accretion

Which are the youngest of the radioactive meteorite rocks?

• Mars

• Chondrites

• Earth

• Moon

True or false? Isotopic ratios cannot be used to determine a rock's age.

• True

• False

We can trace all plants back to the

• cyanobacteria

• glaucophyte

• leucocyte

• chlorophyll

The earliest evidence of life comes from

• soil

• plants

• the ocean

• fossils

True or false? Early scientists thought DNA was the genetic material instead of RNA.

• True

• False

What is the estimated age of the Earth?

• 5.5 billion years

• 4.54 million years

• 4.54 billion years

• 5.5 million years

Which of these is one of Earth's spheres?

• Bioshere

• Hydrosphere

• Geosphere

• All of the above

True or false? Activity by microbes on land led to creating Earth's soils.

• True

• False

The_______ _______ experiment showed evidence that life could form from inorganic molecules.

• Miller-Urey

• Watson-Crick

• Oparin-Haldane

• Avery-Frederick