Chapter 5

Question 1

Predation

Answer 1

Occurs when a member of one species

the predator) feeds directly on all or part of a member of another species (the prey

Question 2

Parasitism

Answer 2

Occurs when one organism (the parasite) feeds on another organism (the host), usually by living on or in the host.

Question 3

Mutualism

Answer 3

Is an interaction that benefits both spe-

cies by providing each with food, shelter, or some other resource.

Question 4

Commensalism

Answer 4

Is an interaction that benefits one

species but has little or no effect on the other.

Question 5

Resource partitioning

Answer 5

It occurs when species competing for similar scarce resources evolve specialized traits that allow them to share resources by using parts
of them, using them at different times, or using them in different ways.

Question 6

Predator

Answer 6

Organism that captures and feeds

on some or all parts of an organism of another species (the prey).

Question 7

Prey

Answer 7

Organism that is killed by an organism
of another species (the predator) and serves
as its source of food.

Question 8

Predator–prey relationship 

Answer 8

Relationship that has evolved between two organisms, in which one organism has become the prey for the other, the latter called the predator.

Question 9

Coevolution

Answer 9

When populations of two different species interact in such a way over a long period of time, changes in the gene pool of one species can lead to changes in the gene pool of the other. Such changes can help both sides to
become more competitive or to avoid or reduce competition.

Question 10

Population

Answer 10

Is a group of interbreeding individuals

of the same species.

Question 11

Age structure

Answer 11

Distribution of individuals among various age groups—can have a strong effect on how rapidly it increases or decreases in size. Age groups are usually described in terms of organisms not mature enough to reproduce (the pre-reproductive age), those capable of reproduction (the reproductive stage), and those too old to reproduce (the post-reproductive stage).

Question 12

Range of tolerance

Answer 12

Range of chemical and
physical conditions that must be maintained
for populations of a particular species to stay
alive and grow, develop, and function normally.

Question 13

Limiting factors

Answer 13

Single factor that limits the growth, abundance, or distribution of the
population of a species in an ecosystem.

Question 14

Limiting factor principle

Answer 14

Too much or too little of any abiotic (physical or chemical) factor can limit or prevent growth of a population of a species in an ecosystem, even if all other factors are at or near the optimal range of tolerance for the species.

Question 15

Environmental resistance

Answer 15

Is the combination of all factors that act to limit the growth of a population. It largely determines an area’s carrying capacity.

Question 16

Carrying capacity

Answer 16

The maximum population of a given species that a particular habitat can sustain indefinitely.

Question 17

Population crash

Answer 17

In such cases, the population suffers a sharp decline, called dieback, or population crash, unless the excess individuals can switch to new resources or move to an area that has more resources.

Question 18

Population density

Answer 18

Is the number of individuals in a

population found in a particular area or volume.

Question 19

Ecological succession

Answer 19

The normally gradual change in species

composition in a given area is called ecological succession.

Question 20

Primary ecological succession

Answer 20

Involves the gradual establishment of biotic communities in lifeless areas where there is no soil in a terrestrial ecosystem or no bottom sediment in an aquatic
ecosystem.

Question 21

Secondary ecological succession

Answer 21

In which a series of communities or ecosystems with different species develop in places containing soil or bottom sediment. This type of succession begins in an area
where an ecosystem has been disturbed, removed, or destroyed, but some soil or bottom sediment remains.

Question 22

Inertia or persistence

Answer 22

The ability of a living system such as a grassland or a forest to survive moderate disturbances.

Question 23

Resilience

Answer 23

The ability of a living system to be

restored through secondary succession after a more severe disturbance.

Question 24

Interspecific competition

Answer 24

Occurs when members of two or more species interact to gain access to the
same limited resources such as food, water, light,
and space.