TEST B4 FINAL: THE LAST LAUGH (NORMAL)

Inner core

The solid, dense center of Earth, made mostly of iron and nickel. It is extremely hot, but the pressure is so great that it remains solid.

Outer core

The liquid layer surrounding the inner core, composed mainly of iron and nickel. Movement in this liquid metal helps generate Earth’s magnetic field.

Mantle

The thick layer of hot rock between the core and the crust. It is mostly solid but can slowly flow over time, allowing convection to occur.

Lithosphere

The rigid outer layer of Earth made of the crust plus the uppermost mantle. It is broken into tectonic plates.

Crust

The thin, outermost rocky surface of Earth. It is the layer where continents, oceans, and all life at the surface are found.

The very first living organisms on the Earth were probably

chemoautotrophs

Our best evidence concerning when Earth began to form comes from which of the following?

radiometric dating of the oldest meteorites

Why is the carbon dioxide cycle important to our existence?

Over long periods of time, it acts as a thermostat to keep Earth's temperature in a relatively narrow range.

When heat and pressure are applied to a sedimentary rock it turns into

a metamorphic rock

At the start of which eon of Earth's history do we find the earliest evidence of life?

Archean

Differentiation is a process by which

denser materials like iron sank into the center of the Earth while less dense materials like rock rose to the surface.

How did water originally arrive on Earth?

It was brought to Earth by icy asteroids which collided with Earth early in the history of the solar system.

What do we currently believe was the main source of the Earth's oceans and atmosphere?

outgassing by volcanoes

Continental crust is ______ than seafloor crust.

older and less dense

The only inner terrestrial planet with plate tectonics is _____

Earth

Visible light from the sun travels through Earth's atmosphere to the surface. The surface absorbs a lot of this visible light and heats up. In which part of the electromagnetic spectrum does the heated surface of Earth emit light?

infrared light

The ozone layer absorbs which light waves?

ultraviolet light

The first multicellular organisms appeared around

1.2 billion years ago

Carbon isotope evidence from rocks found on in Labrador, Canada, suggests that life may have…

existed as far back as 3.95 billion years ago

The idea that life may have migrated to Earth after first originating on another world is sometimes called ________.

panspermia

What is meant by photodissociation?

The breakup of molecules into atoms due to energetic photons.

What happened at the start of the Cambrian Period?

an explosion of genetic diversity appeared, leading to the appearance of the first animals

If we imagine an aerobic (oxygen breathing) life form on another planet, what is likely to be true about it? Select all that apply.

It will have more efficient cellular energy production, It could evolve adaptations that demanded much more energy.

Which of the following best explains what we mean by the "oxygen crisis" in relation to the evolution of life on Earth?

Most early life forms were not adapted to survive as the oxygen content of the atmosphere rose.

How similar are humans and chimpanzees genetically?

very similar, having approximately 98% of DNA sequences in common

Venus probably once had as much water (or water vapor) as Earth. What do we think happened to all this water?

The water molecules were destroyed, and the hydrogen atoms escaped to space.

In a runaway greenhouse effect, more water begins to evaporate from the oceans, which in turn ______.

increases the strength of the greenhouse effect, causing even more warming

There are multiple factors that make a world have a habitable surface. Select all of them from the list below.

presence of an atmosphere, planetary size, distance from the star

What will happen to the Sun's habitable zone in the future as the Sun brightens to become a red giant star?

It will move outward.

During winter at a particular pole on Mars, some of the carbon dioxide in the atmosphere

freeze out onto the surface

We can recognize the oldest surface regions of Mars by the fact that they have

the most impact craters.

Olympus Mons is a ______________

giant volcano.

Which of the following do winds on Mars not cause

hurricanes

When we say that liquid water is unstable on Mars, we mean that

any liquid water on the surface would quickly either freeze or evaporate.

Mars’s seasonal winds are driven primarily by

vaporization of carbon dioxide ice.

The number of impact craters on the slopes of Tharsis volcanoes suggests that they have been inactive

for at least tens of millions of years

Which of the following is NOT a key piece of evidence in favor of past liquid water on Mars?

Orbital photos show a relatively small number of craters on volcanic slopes.

Rivers on Mars __________

existed in the past but are dry today.

Minerals in surface rocks studied by the martian rovers seem to tell us that the rocks

formed in water.

According to the leading hypothesis, if Mars once had much more carbon dioxide in its atmosphere, most of this carbon dioxide is now

gone, because it was lost to space.

Which of the following fundamental properties of Mars could explain why it once had a global magnetic field but later lost it?

Its small size.

The most important factor which contributed to the thinning of the Martian atmosphere was probably

loss of the planet's magnetic field

Which statement must be true if Mars was warmer and wetter in the past?

Mars once had a much thicker atmosphere.

Which Mars orbiter has been measuring the escape of gases from the Martian atmosphere?

MAVEN

Which of the following could potentially explain the detection of methane in the martian atmosphere? Select ALL that apply.

Biological activity, Geological activity