Ch 7 & 8 - The Evolution of Living Things and The History of Life on Earth

Question 1

species

Answer 1

a group of organisms that are closely related and can mate to produce fertile offspring.

Question 2

evolution

Answer 2

the process in which inherited charcateristics within a population change over generations such that new species sometimes arise.

Question 3

fossil

Answer 3

the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock.

Question 4

fossil record

Answer 4

a historical sequence of life indicated by fossils found in layers of the Earth’s crust.

Question 5

trait

Answer 5

a genetically determined characteristic

Question 6

selective breeding

Answer 6

the human practice of breeding animals or plants that have a certain desired traits.

Question 7

natural selection

Answer 7

the process by which individuals that are better adapted to their enviroment survive and reproduce more succesfully than less well adapted individuals do; a theory to explain the mechanism of evolution.

Question 8

generation time

Answer 8

the period between the birth of one generation and the birth of the next generation.

Question 9

speciation

Answer 9

the formation of new species as a result of evolution.

Question 10

relative dating

Answer 10

any method of determining whether an event or objects is older or younger than other events or objects.

Question 11

absolute dating

Answer 11

any method of measuring the age of an object or event in years.

Question 12

geological time scale

Answer 12

the standard method used to divide the Earth’s long natural history into managable parts.

Question 13

extinct

Answer 13

describes a species that has died out completely.

Question 14

plate tectonics

Answer 14

the theory that explain’s how large pieces of the Earth’s outermost layer move and change shape.

Question 15

Precambrian time

Answer 15

the period in the geological time scale from the formation of the Earth to the beginning of the Paleozoic era, from about 4.6 billion to 542 million years ago.

Question 16

Paleozoic era

Answer 16

the gelogical era that followed Precambrian time and that lasted 542 million to 251 million years ago.

Question 17

mesozoic era

Answer 17

the geological era that lasted from 251 million to 65.5 million years ago. Also called the Age of Reptiles.

Question 18

cenozoic age

Answer 18

the most recent geological era, beginning 65 million years ago; also called the Age of Mammals.

Question 19

primate

Answer 19

a type of mammal characterized by opposable thumbs and binocular vision.

Question 20

hominid

Answer 20

a type of primate charcaterized by bipedalism, relatively long lower limbs, and the lack of a tail.

Question 21

homo sapiens

Answer 21

the species of hominids that includes modern humans and their closest ancestors and that first appeared about 100,000 to 160,000 years ago.

Question 22

adaption

Answer 22

a characteristic that improves an individual’s ability to survive and reproduce in a particular enviroment.