What is Life?
These are the 8 defining characteristics that all living things share.
What are the 8 characteristics of life?
Early Earth’s atmosphere lacked this important gas.
What is oxygen (O₂)?
This theory says life came from outer space on meteors or comets.
What is the Panspermia Theory?
The gradual process that turned simple molecules into complex organic ones.
What is chemical evolution?
The first cells to appear on Earth were this type.
What are prokaryotes?
The smallest unit of structure and function in living things.
What is the Cell?
These violent events and lightning helped create the first organic molecules.
What are volcanic eruptions and storms?
This explosion created the universe about 13.8 billion years ago.
What is the Big Bang Theory?
The first “cells” were simple bubbles of lipids and organic molecules.
What are protocells?
The first eukaryotes were most similar to this group of simple organisms.
What are protists?
The ability of an organism to maintain a stable internal environment.
What is homeostasis?
This “soup” of chemicals in Earth’s early oceans is believed to be where life first formed.
What is the primordial soup?
This 1953 experiment proved organic molecules could form under early Earth conditions.
What is the Miller-Urey Experiment?
The process that explains how simple cells evolved into complex ones with organelles.
What is the Endosymbiotic Theory?
The first eukaryotes to evolve were more similar to this kingdom.
What are plants?
The process by which populations change over time.
What is evolution?
The time period when Earth formed.
What is about 4.6 billion years ago?
This theory suggests RNA was the first molecule to store genetic information and catalyze reactions.
What is the RNA World Hypothesis?
According to this theory, clay particles may have acted as catalysts for early organic reactions.
What is the Clay Hypothesis?
The main process that increases life’s diversity over time.
What is evolution or natural selection?
The combination of all chemical reactions within a cell that provide energy.
What is metabolism?
The protective layer that didn’t exist on early Earth, allowing UV radiation to reach the surface.
What is the ozone layer?
This theory says life may have started at hydrothermal vents deep in the ocean.
What is the Deep Sea Thermal Vent Theory?
This cold theory says ice protected early molecules from radiation and helped them form.
What is the Ice Hypothesis?
The combination of genetic variation and environmental change leads to this.
What is biodiversity?