Chapter 21: Populations And Communities

Question 1

Habitat

Answer 1

An environment that provides the things the organism needs to
live, grow, and reproduce.

Question 2

Biotic Factors

Answer 2

The living parts of a habitat

Question 3

Abiotic Factors

Answer 3

The nonliving parts of a habitat

Question 4

Population

Answer 4

All the members of one species in a particular area

Question 5

Community

Answer 5

All the different populations that live together in an area

Question 6

Ecosystem

Answer 6

The community of organisms that live in a particular area,
along with their nonliving surroundings

Question 7

Ecology

Answer 7

The study of how living things interact with one another and
their environments

Question 8

Birth Rate

Answer 8

The number of births in a population in a certain amount of
time

Question 9

Death Rate

Answer 9

The number of deaths in a population in a certain amount of
time

Question 10

Immigration

Answer 10

Moving into a population

Question 11

Emigration

Answer 11

Moving away from a population

Question 12

Population Density

Answer 12

The number of individuals in an area of a specific size

Question 13

Limiting Factor

Answer 13

An environmental factor that causes a population to decrease (can be food and water)

Question 14

Parasite

Answer 14

An organism that benefits off of a host

Question 15

Host

Answer 15

The organism that the parasite is on

Question 16

Niche

Answer 16

The role of an organism in its habitat

Question 17

Predation

Answer 17

An interaction in which one organism kills another for food

Question 18

Successsion

Answer 18

The series of predictable changes that occur in a community over time

Question 19

Predator

Answer 19

The organism that kills another organism for food

Question 20

Prey

Answer 20

The organism that is killed for food

Question 21

Primary Succession

Answer 21

The series of changes that occur in an area where no soil or organisms exist

Question 22

Pioneer Species

Answer 22

The first species to populate an area

Question 23

Secondary Succession

Answer 23

The series of changes that occur in an area where the ecosystem has been disturbed but there are still organisms living there

Question 24

Symbiosis

Answer 24

A close relationship between two species that benefits at least
one of the species

Question 25

Commensalism

Answer 25

A symbiotic relationship in which one species benefits and the
other species is neither helped or harmed.

Question 26

Mutualism

Answer 26

A symbiotic relationship in which both species benefit

Question 27

Parasitism

Answer 27

A symbiotic relationship that involves one organism living on
or inside the other organism and harming it

Question 28

What must organisms obtain from their environment?

Answer 28

food, water, and shelter

Question 29

How many habitats might an area have?

Answer 29

One area may contain many habitats depending on the
needs of organisms

Question 30

What is an biotic factor?

Answer 30

A living part of an environment

Question 31

What is a Abiotic factor?

Answer 31

The living factors of an environment (plants, animals, and fungi are all examples)

Question 32

What is direct observation?

Answer 32

A method for determining population size where all members
of a population are counted.

Question 33

Indirect Observation

Answer 33

A method for determining population size where signs of
organisms are used to estimate how many members are part of
a population.

Question 34

What is sampling

Answer 34

A method for determining population size where a population is too large to be counted.

Question 35

Explain mark and recapture

Answer 35

A method for determining population size where ecologists
capture organisms of a population and “mark” them to find and
study later.

Question 36

What is the difference between predation and parasitism

Answer 36

Parasites don’t kill their hosts like a predator might kill its
prey

Question 37

which events can cause succession in an environment

Answer 37

Floods, fires, earthquakes, mudslides (basically just major disasters)

Question 38

identify several predator adaptations

Answer 38

1. A bat’s echolocation
2. An owl’s ability to see at
   night
3. A crocodile’s retractable second eyelid

Question 39

Be able to identify several prey adaptations

Answer 39

1. An antelope’s speed
2. a skunk’s spray
3. a deers’ spots

Question 40

Contrast primary and secondary succession.

Answer 40

Primary succession may take centuries before a fully formed
ecosystem comes into play

Secondary succession can take as little as a few months or around a
century.