History of Earth and Life, Unit 8, 9th Grade Bio

Continuing and naturally occurring actions such as wind and rain

any and all activities performed by living organisms

A mixture of gases that surrounds a planet or moon.

Earth's outermost layer.

A form of oxygen that has three oxygen atoms in each molecule instead of the usual two.

a small rocky body

Plants use the sun's energy to convert water and carbon dioxide into sugars

Protective layer in atmosphere that shields earth from UV radiation.

Change over time

the extinction of a large proportion of the world's species in a very short time period due to some extreme and rapid change or catastrophic event.

the process by which water vapor and other gases and compounds are brought to Earth's surface by volcanism and released into the atmosphere

All of the chemical reactions that occur within an organism

theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms

hypothesis that RNA served as the genetic information of early life

An explanation of the origin of life, in which life began as a self-sustaining, organized system consisting of chemical reactions between simple molecules enclosed within a boundary

The hypothesis that the continents slowly move across Earth's surface.

A plate boundary where two plates move toward each other.

the relatively thick part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.

earths crust located under the ocean

A plate boundary where two plates move away from each other.

The shaking that results from the movement of rock beneath Earth's surface.

a type of rock that forms from the cooling of molten rock at or below the surface

An underwater moutain chain where new ocean floor is formed

The name of the single landmass that broke apart 200 million years ago and gave rise to today's continents

the edges of tectonic plates.

a deep valley that forms where two plates move apart

The process that creates new sea floor as plates move away from each other at the mid-ocean ridges

in tectonic plates, the site at which an oceanic plate is sliding under a continental plate.

Large movable plates under the Earth's surface.

A plate boundary where two plates move past each other in opposite directions

A deep, steep-sided canyon in the ocean floor.

A record of the geologic events and life forms in Earth's history

billion years ago

million years ago

age of the earth

3.5 billion years ago