Chapter 3

Question 1

what is a species

Answer 1

particular type of organism

Question 2

what is a population

Answer 2

group of individuals that live in a specific region at a particular time

Question 3

what is evolution

Answer 3

changes in population overtime (generation to generation)

Question 4

what is natural selection

Answer 4

when inherited characteristics that enhance survival are passed down more often than characteristics that do not

Question 5

who is Charles Darwin and Alfred Wallace

Answer 5

explained that natural selection explains the variety of life on Earth

Question 6

what is adaptation

Answer 6

when traits that lead to better reproductive success are passed to other generations

Question 7

what are mutations

Answer 7

accidental changes in DNA

Question 8

what is convergent evolution

Answer 8

when closely related species that live in very different environments diverge in traits and vice versa

Question 9

what is biodiversity

Answer 9

lifes complexity

Question 10

what is artificial selection

Answer 10

when humans select their own direction of selections

Question 11

what is speciation

Answer 11

process in which new species are generated

Question 12

what is a phylogenetic tree

Answer 12

type of tree like graph that represents divergence history

Question 13

what is a fossil

Answer 13

imprint in stoen of a dead organisms

Question 14

what is the fossil record

Answer 14

the cumulative body of fossils worldwide

Question 15

what is extinction

Answer 15

the disappearance of a species on earth

Question 16

what does it mean when a species is endemic

Answer 16

the species does not occur anywhere else on earth besides its own habitat

Question 17

what is background extinction rate

Answer 17

rate at which a species gradually goes extinct

Question 18

what is a mass extinction event

Answer 18

event that wipes out massive numbers of a species all at once

Question 19

what is a community

Answer 19

assemblage of populations of interacting species

Question 20

what is the biosphere

Answer 20

total amount of living things on Earth

Question 21

what are ecologists

Answer 21

scientists that study relationships in the biosphere

Question 22

what is population ecology

Answer 22

examines dynamics of population change

Question 23

what is community ecology

Answer 23

focuses on patterns of species diversity

Question 24

what is an ecosystem

Answer 24

communities and non living things in which members interact

Question 25

what is ecosystem ecology

Answer 25

addresses flow of energy and nutrients

Question 26

what is landscape ecology

Answer 26

studies how populations are distributed throughout regions

Question 27

what is a niche

Answer 27

organisms functional role in a community

Question 28

what is a specialist

Answer 28

species with very specific requirements

Question 29

what is a generalist

Answer 29

species with broad tolerance

Question 30

what is a habitat

Answer 30

environment where an organisms lives

Question 31

what is habitat selection

Answer 31

when a mobile organism choose a habitat to live in

Question 32

what is population size

Answer 32

number of organisms present at a time

Question 33

what is population density

Answer 33

number of individuals per unit area

Question 34

what is population distribution

Answer 34

spatial arrangement of organisms in an area

Question 35

what is a sex ratio

Answer 35

the proportion of males to females

Question 36

what is age structure

Answer 36

relative number of individuals of different ages in a poplulation

Question 37

what is the formula for natural increase

Answer 37

birth rate - death rate

Question 38

what is the formula for population growth rate

Answer 38

(birthrate - deathrate) + (immigration rate - emigration)

Question 39

what is exponential growth

Answer 39

when a population grows at a fixed percentage every year

Question 40

what are limiting factors

Answer 40

factors that limit growth

Question 41

what is carrying capacity

Answer 41

maximum population size

Question 42

what is logistic growth

Answer 42

when a population growing at an exponential rate slows and is brought to a standstill

Question 43

what is a density independent limiting factor

Answer 43

influence is independent of population density

Question 44

what is a density dependent limiting factor

Answer 44

limiting factors that depend on population density

Question 45

what is the life history theory

Answer 45

explains how natural selection influences patterns in reproduction, survival, and life span

Question 46

what is ecotourisms

Answer 46

when a place's natural areas attract tourists to it