L 5.1 how populations grow and L5.2 how population grow

Question 1

How do ecologists study populations?

Answer 1

Researchers study populations’
geographic range, density and distribution,
growth rate, and age structure.

Question 2

geographic range

Answer 2

The area inhabited by a population

Question 3

Population density

Answer 3

refers to the number of individuals per unit area.

Question 4

Distribution

Answer 4

refers to how individuals in a population are spaced out
across the range of the population

randomly, uniformly, or mostly
concentrated in clumps.

Question 5

A population’s growth rate

Answer 5

determines whether the population size:
increases (positive growth rate )
decreases (negative growth rate )
stays the same (zero ).

Question 6

age structure

Answer 6

the number of males and females of each age a population contains.

Question 7

What factors affect population growth?

Answer 7

The factors that can affect population size are the birthrate, death rate, and

the rate at which individuals enter or leave the population.

Question 8

A population may grow if
individuals move into its range from
elsewhere, a process called

Answer 8

immigration

Question 9

A population may decrease in size
if individuals move out of the
population’s range, a process called

Answer 9

emigration

Question 10

What happens during exponential growth?

Answer 10

Under ideal conditions with unlimited resources, a population will grow exponentially.

Question 11

What is logistic growth?

Answer 11

Logistic growth occurs when a population’s growth slows and then stops, following a period of exponential growth.

Question 12

What factors determine carrying capacity?

Answer 12

Acting separately or together, limiting factors determine the carrying capacity of an environment for a species.

Question 13

limiting factor

Answer 13

is a factor that controls the growth of a population.

Question 14

What limiting factors depend on population density?

Answer 14

competition, predation, herbivory, parasitism, disease, and stress from overcrowding.

Question 15

What limiting factors do not typically depend on population density?

Answer 15

Unusual weather such as hurricanes, droughts, or floods, and natural disasters such as wildfires,

can act as density-independent limiting factors.

Density-independent limiting factors affect all populations in similar ways, regardless of population size and density.