Life on Planet Earth - Chapter 5: Evolution

Flashcards from lecture notes on the origin of life on Earth.

Carbon Requirement for Life

Must contain carbon.

Energy Use

Extract and use energy from their environment.

Metabolic Activities

Must perform metabolic activities including cellular respiration.

Growth and Reproduction

Must be able to grow or reproduce.

Water Requirement

Require water.

Cell Membrane

All cells must have a cell membrane.

Adaptation

Ability to adapt to the environment.

Lord Kelvin's Age Estimate

Early estimate of Earth's age by Lord Kelvin, based on the cooling rate of molten rock, but was inaccurate.

Convection Current

Occurs when hot air rises and cold air sinks.

Radiation

Occurs when an object gives off heat.

Meteorites

Used to calculate the age of the Earth by analyzing when they hit the Earth.

4.55 Billion Years Old

Approximate age of the Earth calculated from meteorite data.

End of Meteor Bombardment

Time (4-4.55 BYA) when meteors stopped hitting the Earth, allowing life to take hold.

Chemosynthetic Bacteria

Bacteria that used the Earth's energy to make food and oxygen (3.5 BYA).

Photosynthetic Bacteria

Bacteria using the sun to make food and oxygen (3.5 BYA).

Oxygen Catastrophe

Time (2.3 BYA) when the atmosphere became rich in oxygen, leading to the extinction of organisms that could not use oxygen.

Heterotrophic Unicellular Organisms

Single-celled organisms that used oxygen and produced carbon dioxide as a waste product.

Multicellular Protists

Multicellular protists used CO2 to make oxygen (1.5 BYA).

Plants Populate Land

Time (530 MYA) when plants populated the land.

First Vertebrates on Land

Time (370 MYA) when the first vertebrates walked on land.

Dinosaurs Dominate

Time (230 MYA) when dinosaurs ruled the world.

First Humans

Time (2 MYA) when the first humans walked the Earth.

Urey-Miller Experiment

Experiment that proved life could arise from the primitive atmosphere using methane, ammonia, water, and hydrogen gas with an electrical spark.

DNA

Instructions for what proteins to make.

RNA

Carries instructions to ribosomes where proteins are made.

Lipids

Found in all cell membranes

ATP

Energy molecule for all living things.