2024 Earth History

Question 1

Uniformitarianism

Answer 1

Idea that processes on Earth in the past are the same as those in the present

Question 2

Superposition

Answer 2

Idea that younger rock layers form on top of older rock layers

Question 3

Geologic Eon

Answer 3

Longest unit of geologic time; every fossil we have studied is in the Phanerozoic Eon

Question 4

Geologic Era

Answer 4

Long unit of geologic time; for example, the whole time dinosaurs were alive is one era

Question 5

Geologic Period

Answer 5

Basic unit of geologic time; there are 13 or 14 of these on the Geologic time scale

Question 6

Geologic Epoch or Stage

Answer 6

Smallest unit of geologic time, only a few million years long

Question 7

Mass Extinction

Answer 7

When a large percent of life died off at once; often the border between eras or periods

Question 8

DNA

Answer 8

A chemical, found in the nucleus of cells, that contains that living thing’s genes

Question 9

gene

Answer 9

Part of DNA with the instructions for one protein molecule to be made at the ribosomes

Question 10

protein

Answer 10

A molecule in a living thing that helps cause its traits (characteristics)

Question 11

variation

Answer 11

A difference in a trait caused by different genes within a population of living things

Question 12

natural selection

Answer 12

When living things with certain traits are able to survive and/or reproduce better than others

Question 13

biotic selective pressure

Answer 13

A living factor that causes natural selection, like predators, competition for food, or mates

Question 14

abiotic selective pressure

Answer 14

A nonliving factor that causes natural selection, like climate or disasters

Question 15

adaptation

Answer 15

The result of natural selection, a trait that helps a living thing fit its environment

Question 16

evolution

Answer 16

When enough natural selection and adaptations have happened to permanently change a species or make a new species