Chapter Three- Population Dynamics

Question 0

What is the distribution of a species?

Answer 0

The is where the species lives: this is its geographic range & preferred habitat

Question 1

What does Abiotic stand for and what are 3 examples?

Answer 1

Abiotic, are the non living factors in a given environment.

1. Water
2. Sunlight
3. Temperature

Question 2

What does the abundance of a species mean?

Answer 2

This is the number of individuals

Question 3

What are 3 factors that determine the distribution & abundance of organisms?

Answer 3

1. Characteristics of the environment (Abiotic factors)
2. Characteristics of the organism (Adaptions)
3. Interactions between organisms (Ecological Relationships)

Question 4

What is population size?

Answer 4

This is the number of individuals in the population

Question 5

Population is affected by4 processes- what are they?

Answer 5

1. Birth
2. Death
3. Immigration
4. Emigration

Population size = (B+I) - (D+E)

Question 6

What is population density?

Answer 6

This is the number of organisms in an area

Question 7

How is population density expressed?

Answer 7

1. Terrestrial organisms: number per m2 or km2
2. Aquatic organisms: number per L or m3
3. Some plants: mass per m2 (used for plants such as ferns which cover a large area & may grow from only a few stems)

Question 8

What is carrying capacity?

Answer 8

(K)- carrying capacity
Carrying Capacity of an area is the maximum population size that a habitat can support in a sustainable manner.

Example:

9 desks and chairs in a class room, the (K) carrying capacity would be 9

There fore K= 9

Question 9

How can the carrying capacity of an environment vary?

Answer 9

This can vary due to a number of factors- such as:

1. How well an organism utilises an environment
2. Competition of resources
3. Abiotic factors (such as weather conditions)

Question 10

What happens when a population reaches its carrying capacity of an area?

Answer 10

There is a dynamic equilibrium

Question 11

Explain Expotential population?

Answer 11

This is rapid growth in population, it usually occurs when their are no limiting factors and abundant resources.

Question 12

What shape do Exponential growth rates, produce?

Answer 12

A J shape.

Question 13

What is the Lag phase?

Answer 13

The late phase is a slow growth which is called the initial slow growth

Question 14

What is Logistic Growth? And what shale does it form?

Answer 14

It forms an S shape. And this is typical of growth of most populations. The upper li,it of the curve is determined by he carrying capacity of the habitat.

Question 15

How is the growth of a population influenced?

Answer 15

The growth of populations is influenced by a number of factors that we previously learned: the impact of these on a population may be dependent on the density of the population. We say that factors can be density dependent or density independent.

Question 16

What are some density dependent factors;

Answer 16

The impact of these factors depend on the density of a population in a given area. 
Some examples:
-competition
-starvation
-spread of disease
-parasites
-pests
-human activities

Question 17

What are some density independent factors? Give some examples:

Answer 17

The impact if these factors are not dependent on the density of a population in a given area. The impact will be the same wether their are few or many individuals in an area. 
Some examples:
-drought
-bushfire
-floods

Question 18

What is a keystone species?

Answer 18

A keystone species is a plant or animal that plays a unique & crucial role in the way an ecosystem functions. Without Keystone species, the ecosystem would be dramatically different or cease to exist all together.

Question 19

Can a Keystone species be a predator? Explain.

Answer 19

A keystone species is often, but not always, a predator. A few predators can control the distributions & population of large numbers of prey species.

Question 20

What would happen if Keystone species were wiped out?

Answer 20

A keystone species’ disappearance would start a dominos effect. Other species in the habitat would also disappear and become extinct.

Question 21

What would happen in a habitat without a keystone species?

Answer 21

Without the keystone species, new plants or animals could also come into the habitat and push out the native species.

Question 22

What is Birth rate (b)?

Answer 22

The number of births per thousand of a population over a given time,eg. Number of births/1000/year

Question 23

What is Death rate (d)?

Answer 23

The number of deaths per thousand of a population over a given time,eg. Number of deaths/1000/year

Question 24

What is immigration rate (i)b

Answer 24

The number of organisms per thousand entering a population over a given time,eg. Number of arrivals/1000/year

Question 25

What is emigration rate (e)?

Answer 25

The number of organisms per thousand leaving a population over a given time, eg. Number of departures/1000/year

Question 26

What is Aubndance?

Answer 26

The number of species in a population

Question 27

What is geographic distribution?

Answer 27

This is e natural arrangement & apportionment of the various form of animals & plants in the different regions & localities of the earth.

Question 28

What is a R-selected species?

Answer 28

This is a fast growing & reproductive organism, often first to occupy unused resources and living space.

Question 29

What is a k-selected species?

Answer 29

This is a slow growing, long lived species typical of those in a climax community. Because they eat large portions of the provided food.

Question 30

What does Biodiversity allow people to do?

Answer 30

Biodiversity enables humans to sustain & ensure that vulnerable species persist and contribute to the planets biodiversity.

Question 31

Define population:

Answer 31

Population is a group of individuals belonging to the same species living in a particular area at the same time.

Question 32

What is density?

Answer 32

The number of individuals in a given area; can use biomass or volume for smaller individuals.