Chapter 4

Question 1

Species

Answer 1

is a set of individuals that can mate and produce fertile offspring

Question 2

Biomass

Answer 2

large regions such as forests, deserts, and grasslands with distinct climates and certain species (especially vegetation) adapted to them

Question 3

Fossils

Answer 3

mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds, or impressions of such items found in rocks

Question 4

Biological Evolution

Answer 4

the process whereby earth’s life changes over time through changes in the genetic characteristics of populations

Question 5

Theory of Evolution

Answer 5

all species descended from earlier, ancestral species

Question 6

Natural selection

Answer 6

in which individuals with certain traits are more likely to survive and reproduce under a particular set of environmental conditions than are those without the traits

Question 7

Mutations

Answer 7

random changes in the DNA molecules

Question 8

Adaptation

Answer 8

The favored individuals possess heritable traits that give them some advantage over
other individuals in a given population

Question 9

Differential Reproduction

Answer 9

which enables individuals with the trait to produce more surviving offspring than other members of the population produce

Question 10

Speciation

Answer 10

one species splits into two or more different species

Question 11

Geographic Isolation

Answer 11

occurs when different groups of the same population of a species become physically
isolated from one another for a long period of time

Question 12

Reproductive Isolation

Answer 12

mutation and change by natural selection operate independently in the gene pools of geographically isolated populations

Question 13

Extinction

Answer 13

process in which an entire species ceases to exist (biological extinction) or a population of a species becomes extinct over a large region, but not globally

Question 14

Endemic Species

Answer 14

Species that are found in only one area

Question 15

Background Extinction

Answer 15

species have disappeared at a low rate

Question 16

Mass Extinction

Answer 16

significant rise in extinction rates above the background level

Question 17

Species Diversity

Answer 17

the number and variety of species it contains

Question 18

Ecological Niche

Answer 18

Scientists describe the role that a species plays in its ecosystem

Question 19

Generalists Species

Answer 19

have broad niches

Question 20

Specialists Species

Answer 20

occupy narrow niches

Question 21

Native Species

Answer 21

are those species that normally live and thrive in a particular ecosystem

Question 22

Nonnative Species

Answer 22

Other species that migrate into, or are deliberately or accidentally introduced into, an ecosystem

Question 23

Indicator Species

Answer 23

Species that provide early warnings of damage to a community or an ecosystem

Question 24

Keystone Species

Answer 24

species whose roles have a large effect on the types and abundance of other species in an ecosystem

Question 25

Foundation Species

Answer 25

species that play a major role in shaping their communities by creating and enhancing their habitats in ways that benefit other species

Question 26

Biodiversity

Answer 26

the variety of the earth’s species, or varying life-forms, the genes they contain, the ecosystems in which they live, and the ecosystem processes of energy flow and nutrient cycling
that sustain all life