Chapter 4 Vocabulary

Question 1

Species

Answer 1

is a set of individuals that can mate and pro-

duce fertile offspring. Every organism is a member of a certain species with certain distinctive traits.

Question 2

Biomes

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 (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. In other words, life comes from life.

Question 6

Natural selection

Answer 6

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

Adaption (adaptive trait)

Answer 7

any heritable trait that improves the ability of an individual organism to survive and to reproduce at a higher rate than other individuals in a population are able to do under prevailing environmental conditions.

Question 8

Differential reproduction

Answer 8

Enables individuals with the trait

to produce more surviving offspring than other members of the population produce.

Question 9

Speciation

Answer 9

One species splits into two or more different species.

Question 10

Geographic isolation

Answer 10

Occurs when different groups

of the same population of a species become physically isolated from one another for a long period of time.

Question 11

Endemic species

Answer 11

Species that are found in only one area are and are especially vulnerable to extinction.

Question 12

Background extinction

Answer 12

Throughout most of the earth’s long history, species have disappeared at a low rate.

Question 13

Mass extinction

Answer 13

Is a significant rise in extinction rates above the background level.

Question 14

Reproductive isolation

Answer 14

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

Question 15

Extinction

Answer 15

A 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 (local extinction).

Question 16

Species diversity

Answer 16

An important characteristic of a community and the ecosystem to which it belongs is this, or its number and variety of species it contains.

Question 17

Ecological niche (niche)

Answer 17

Scientists describe the role that a species

plays in its ecosystem as its ecological niche, or simply niche (often pronounced “nitch”).

Question 18

Generalist species

Answer 18

Scientists use the niches of species to classify them broadly as generalists or specialists. Generalist species have broad niches.

Question 19

Specialist species

Answer 19

Specialist species occupy narrow
niches. They may be able to live in only one type of habitat, use just one or only a few types of food, or tolerate a narrow range of climatic and other environmental conditions.

Question 20

Native species

Answer 20

Are those species that normally live

and thrive in a particular ecosystem.

Question 21

Nonnative species

Answer 21

Other species that migrate into, or are deliberately or accidentally introduced into, an ecosystem are called nonnative species, also referred to as invasive, alien, and exotic species.

Question 22

Indicator species

Answer 22

Species that provide early warnings of damage to a community or an ecosystem are called indicator species.

Question 23

Keystone species

Answer 23

Are species whose roles have a large

effect on the types and abundance of other species in an ecosystem.

Question 24

Foundation species

Answer 24

Another important type of species in some ecosystems is a foundation species, species that play a major role in shaping their communities by creating and enhancing their habitats in ways that benefit other species.

Question 25

Biological diversity (biodiversity)

Answer 25

Is 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.

Question 26

Mutations

Answer 26

Random changes in the DNA molecules.