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Population Dynamics
Practice of why populations change and what causes them to change
28
Science
8th Grade
03/29/2010

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Cards

Term
What do we call the study of why populations change and what causes them to change?
Definition
population dynamics
Term
Define carrying capacity
Definition
the maximum number of individuals an ecosystem can support
Term
What do we call a measure of the individuals in a certain space at a particular time?
Definition
population density
Term
What are the three stages of change that populations go through?
Definition

growth

 

stability

 

death

Term
What are the three resources that all living things need?
Definition

water

 

food

 

space

Term
If the size of a population in an area decreases, then the density does what?
Definition
decreases
Term
What is the formula for tracking population change?
Definition

population change =

(birth+immigration)-(death+emigration)

Term
Define immigration
Definition
the movement of individuals into a population
Term
Define emigration
Definition
the movement of individuals out of a population
Term
A factor that prevents the continuing growth of a population in an ecosystem is called what?
Definition
limiting factor
Term
Name three non-living factors that prevents population growth (limiting factors)
Definition

air (oxygen)

 

water

 

light

 

temperature

Term
What do we call a limiting factor that affects a population when density is high?
Definition
density-dependent factor
Term
Give me two examples of a density-dependent factor.
Definition

disease

 

competition (for food, water, space)

 

parasitism

 

predation (predators)

Term
What do we call a limiting factor that affects a population whether density is high or low?
Definition
density-independent factor
Term
List three examples of a density-independent factor.
Definition

wildfires

 

floods

 

tornados

 

drought

 

freezing temperatures

 

earthquakes

Term
What do we call species that reproduce rapidly if their population falls below carrying capacity?
Definition
opportunists
Term
What do we call species that allow them to remain at or near carrying capacity for long periods of time?
Definition
competitors
Term
List 3 examples of organisms that are opportunists.
Definition

insects

 

dandelions

 

bacteria

 

algae

Term
List three examples of organisms that are competitors.
Definition

wolves

 

humans

 

bears

 

elephants

Term
The addition of harmful substances to the environment is called what?
Definition
pollution
Term
List two ways that human population growth can reduce populations or cause them to become extinct?
Definition

pollution

 

overfishing/overhunting

 

introducing new species into a population

 

destroying habitats

Term
List four things that scientists look at when a population changes?
Definition

birth rate

death rate

immigration

emigration

 

Term
Non-living things that effect populations in an ecosystem are called ______________ factors.
Definition
abiotic
Term
Living things that effect populations in an ecosystem are called ___________ factors.
Definition
biotic
Term
A field has lots of ants and wild flowers growing in it but that same field can only support 5 deer. Does the field have a high carrying capacity or low carrying capacity for for ants?
Definition

high carrying capacity

The field can support a lot of ants with food, water, and space

Term
Explain one thing that might happen if a population of fish in a pond would go beyond the carrying capacity of that pond?
Definition

The fish could start to compete by fighting with one another.

They could run low on food and start to starve to death.

Diseases could start to spread from fish to fish because they are too close together.

Term
A death rate that is higher than the birth rate could lead to what?
Definition
extinction
Term

In 2019, a hive of honey bees had 250 bees. In 2020, 55 new bees were born in the hive and 32 new bees moved into the hive. Also, there were 40 bees from the hive that died and 66 bees left the hive for good.

 

What was the population of bees in 2020?

 

What was the population change of bees from 2019 to 2020?

Definition

population change =

(birth + immigration) - (death + emigration)

 

(55 + 32) - (40 + 66)

 

87 - 106

= -19

 

There was a loss of 19 bees in the hive between 2019 and 2020

 

250 - 19 = 231 total bees in the hive in 2020

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