Chapter 12 Vocab

Question 0

Radiometric dating

Answer 0

Tequnique that uses the natural decay rate of isotopes to calculate the age of material

Question 1

Relative dating

Answer 1

Estimate age of a fossil based on the location of fossils in strata

Question 2

Isotopes

Answer 2

Atoms of an element that have the same number of protons but a different number of neutrons

Question 3

Half life

Answer 3

Amount of time it takes for half of the isotope in a sample number of protons to decay into its product isotope

Question 4

Index fossils

Answer 4

Existed only during specific spans of time over large geographic areas

Question 5

Geologic time scale

Answer 5

Time scale representing the history of earth

Question 6

Era

Answer 6

Lasts tens to hundred of millions of years and consisting of two or more periods, second largest unit of geologic time

Question 7

Periods

Answer 7

Most of commonly used units of time on the geologic time scale, lasts tens of millions of years and is associated with a particular type of rock system

Question 8

Epoch

Answer 8

Smallest unit of geologic time, lasts several million years

Question 9

Nebula

Answer 9

Rotating cloud of gas and dust

Question 10

Ribozymes

Answer 10

RNA molecule that can catalyze specific chemical reactions

Question 11

Cyanobacteria

Answer 11

Bacteria that can carry out photosynthesis

Question 12

Endosymbiosis

Answer 12

Ecological relationship in which members of every major animal group alive today evolved

Question 13

Paleozoic

Answer 13

Era of geologic time during which members of every major animal group alive today evolved

Question 14

Cambrian explosion

Answer 14

Earliest part of the Paleozoic era, when a huge diversity of animal species evolved

Question 15

Mesozoic

Answer 15

Era during which dinosaurs romed earth

Question 16

Cenozoic

Answer 16

Geologic time period that began 65 million years ago and continues today

Question 17

Primates

Answer 17

Mammal with flexible hands and feet, forward-looking eyes, and enlarged brains relative to body size

Question 18

Prosimians

Answer 18

Oldest primate group that includes mostly small, noctural primates

Question 19

Anthropoids

Answer 19

Humanlike primate

Question 20

Hominids

Answer 20

Primate that walks upright, has long lower limbs, oppose able thumbs and other four fingers, and a relatively large brain

Question 21

Bipedal

Answer 21

Animal that walks on two legs