Chapter 3

Question 1

Species

Answer 1

Classification of organism whose members can interbreed and produce fertile offspring.

Question 2

Population

Answer 2

Group of individuals within a species that live in one geographic area.

Question 3

Evolution

Answer 3

Genetic changes alter physical characteristics and behaviour of a population over generations.

Question 4

Natural selection

Answer 4

Process that favors certain inherited characteristics, causing them to be passed on more frequently.

Question 5

Adaptation

Answer 5

Evolution of genes that lead to better reproductive success in a population.

Question 6

Mutations

Answer 6

Accidental changes to DNA, which cause genetic variation among individuals (separate from mixing through sexual reproduction).

Question 7

Convergent evolution

Answer 7

Unrelated species in similar environments independently acquire similar traits (sometimes due to selective pressures).

Question 8

Artificial selection

Answer 8

Selection caused by humans, such as domesticating dogs, cats, and livestock.

Question 9

Biodiversity/biological diversity

Answer 9

Variety of life across levels (species, genes, populations, communities).

Question 10

Speciation

Answer 10

Process by which new species are generated.

Question 11

Allopatric speciation

Answer 11

Populations become physically separated over geographic distances. Populations eventually grow so different they can no longer mate.

Question 12

Phylogenetic trees

Answer 12

Tables analyzing genes and external traits to represent the history of divergence.

Question 13

Genus

Answer 13

Grouping of related species. Related genera are grouped into families.

Question 14

Fossil

Answer 14

Imprint in stone of a dead organism.

Question 15

Fossil record

Answer 15

Body of fossils worldwide.

Question 16

Extinction

Answer 16

Most species that once lived have disappeared. Extinction occurs when the environment changes faster than species can adapt.

Question 17

Background extinction rate

Answer 17

Rate of gradual extinctions (most extinctions).

Question 18

Mass extinction events

Answer 18

Events that wiped out 50-95% of Earth’s species (e.g. Permian extinction).

Question 19

Ecology

Answer 19

Study of interactions among organisms and with their environments on different levels.

Question 20

Organism

Answer 20

Single living thing.

Question 21

Population

Answer 21

Group of individuals of the same species in the same area.

Question 22

Community

Answer 22

All populations of species that live and interact in an area.

Question 23

Community ecology

Answer 23

Studies interactions of species in an area.

Question 24

Ecosystems

Answer 24

Communities and all abiotic/nonliving parts of the environment.

Question 25

Ecosystem ecology

Answer 25

Studies flow of energy and nutrients between living and nonliving parts.

Question 26

Biosphere

Answer 26

Total of all living things/habitats on Earth.

Question 27

Landscape ecology

Answer 27

Studies how ecosystems/communities/populations are distributed across Earth.

Question 28

Habitat

Answer 28

Environment an organism lives in (including rock, soil, leaf litter, plant life), which varies by size.

Question 29

Habitat use

Answer 29

Patterns created by the ability of organisms to survive in some habitats but not others.

Question 30

Habitat selection

Answer 30

Mobile organisms can choose where they live.

Question 31

Niche

Answer 31

Organism's role in its community (resource use, interaction with other organisms).

Question 32

Specialists

Answer 32

Species with narrow niches.

Question 33

Generalists

Answer 33

Species with wider niches.

Question 34

Population size

Answer 34

Number of organisms in an area at a time.

Question 35

Population density

Answer 35

Number of individuals per unit area.

Question 36

Population distribution

Answer 36

Spatial arrangement of organisms in an area.

Question 37

Random population distribution

Answer 37

Population distribution with no particular pattern.

Question 38

Uniform population distribution

Answer 38

Population distribution where individuals are spaced evenly.

Question 39

Clumped population distribution

Answer 39

Population distribution where individuals concentrate in certain areas.

Question 40

Sex ratio

Answer 40

Proportion of males to females.

Question 41

Monogamous species

Answer 41

Sex ration of 1:1.

Question 42

Age structure

Answer 42

Number of individuals of different ages within a population.

Question 43

Natality

Answer 43

Births in a population.

Question 44

Mortality

Answer 44

Deaths in a population.

Question 45

Immigration

Answer 45

Arrival of outside individuals to a population.

Question 46

Emigration

Answer 46

Departure of individuals from a population.

Question 47

Rate of natural increase

Answer 47

Birth rate - death rate.

Question 48

Exponential growth

Answer 48

Population increased by a fixed percentage each year.

Question 49

Limiting factors

Answer 49

Physical, chemical, and biological constraints to a population.

Question 50

Carrying capacity

Answer 50

Maximum population size an environment can sustain.

Question 51

Logistic growth

Answer 51

Slowing of population growth as a population reaches its carrying capacity.

Question 52

Density-dependent factors

Answer 52

Factors that rise and fall with population density (e.g. Predation, disease).

Question 53

Density-independent factors

Answer 53

Factors unaffected by population density (e.g. Temperature, natural disasters).

Question 54

Ecotourism

Answer 54

Tourism of natural areas (which is increased by efforts of organizations to protect land, remove alien species, and restore native habitats).