Unit 1 - Origin Review

Which of the following is the best description of a nebula?

• a large cloud of dust and gas

• a dense cluster of billions of stars

• a single sun surrounded by planets and asteroids

• 
  a large cloud of comets and asteroids surrounding a solar system

Which best explains how volcanoes could have contributed to the formation of oceans on the Earth?

• Water vapor was contained in the lava was released into the atmosphere and turned into liquid water.

• Particles contained in the smoke served as condensation nuclei to allow water vapor to condense.

• 
  Water vapor contained in the gases from the volcano condensed into water as the planet cooled.

• The lava carved out the basins in which the water vapor collected and became groundwater.

Which term refers to the combined mass of water found on, under, and over the surface of a planet?

• biosphere

• lithosphere

• hydrosphere

• atmosphere

Approximately how many years ago did the Big Bang occur, according to current scientific estimates?

• 4 billion years

• 1 billion years

• 10,000 years

• 13.8 billion years

What percentage of Earth's surface is covered by oceans?

• 
  50%

• 70%

• 80%

• 90%

Which of the following is a primary producer in marine ecosystems?

• Phytoplankton

• Coral

• 
  Sea Cucumber

• Sea Urchin

Which marine ecosystem is characterized by a high diversity of species and is often referred to as the "rainforest of the sea"

• Polar Ice Cap

• Deep Sea

• Coral Reef

• 
  Kelp Forest

What is the term for an area that lays between low and high tide and organisms are exposed to regular extreme changes?

• Abyssal Plain

• 
  Pelagic Zone

• Estuary

• Intertidal Zone

The Earth formed about 4.5 billion years ago, and the oceans about 3.8 million years ago. Which of the following best explains why scientists think the earliest oceans formed 3.8 billion years ago?

• The discovery of chemical compounds such as hydrates in rock dated to 3.8 billion years ago.

• The existence of sedimentary rock dated to 3.8 billion years ago because sedimentary rock cannot form without a water environment.

• Fossil remains of simple marine creatures in sedimentary rock dated to 3.8 billion years ago.

• Calculating the average cooling rate of the Earth which would have resulted in temperatures suitable for the condensation of water vapor.

Which of the following gases was NOT present in Earth's early atmosphere?

• carbon dioxide

• oxygen

• nitrogen

• water Vapor