Population Regulation

Question 1

Density Dependent

Answer 1

Have greater affect when the population is denser and less affect when the population is less dense.

• Competition for resource (water and food)
• Shelter (to hide/reproduce)
• Predation- population is large and dense therefore more interaction and contact and high level predators
• Disease- more interaction and contact. Organisms that live in close proximity (diseases spread quicker).

Question 2

Density Independent

Answer 2

May affect all individuals in a population equally but some members of the population may be better able to adjust to them.
Physical Factors- rainfall, temperature, humidity, acidity and salinity
Catastrophic Events- flood, fire ,drought, volcanic eruption, tsunami, earthquake

Question 3

Environmental limiting factors

Answer 3

Any factor that limits the growth of a population (inhibits population growth).

Question 4

Biotic potential

Answer 4

Number of offspring capable of being produced by individuals of a species.

Question 5

Carrying capacity

Answer 5

The total population able to be supported by a particular environment.

Question 6

Negative Feedback

Answer 6

A change which reverses a particular trend. Sets in motion reverse processes.

Question 7

Rate of increase or decrease of a population

Answer 7

r=(b+i)-(d+e) 
b= births
i= immigrants 
e= emigrants 
d= deaths

Question 8

Density dependent/independent

Answer 8

They influence the individuals ability to reproduce. (Natality/ birthrate is affected).
Can cause ill health or death. (Increases mortality/ death rate).

Question 9

Population growth

Answer 9

The difference immigration and emigration.
A population in equilibrium B, D, E, I balance out and there is not net change in the population abundance. When losses exceed gains, the population declines.

Question 10

Population equilibrium
A declining population
An increasing population
Rate of population change

Answer 10

Population equilibrium B+I=D+E
A declining population D+E> B+I
An increasing population B+I > D+E
Rate of population change= 
B rate- D rate + net migration rate (positive or negative)

Question 11

What is a population?

Answer 11

A population consists of all organisms of a given species that live in a particular area.

Question 12

What are two important measures of a population?

Answer 12

Population size- the number of individuals

Population Density- the number of individuals per unit area or volume.

Question 13

Density Equation

Answer 13

(total number of species)/(sample area)

Question 14

Abundance Equation

Answer 14

total area x density