How Populations Grow
Types of Population Growth
Human Population Growth
Biodiversity
Humans & Global Change
100
For a population to grow birthrate must be greater than _______________.
Death rate
100
The number of individuals a given environment can support based upon the resources available is referred to as _____________.
What is carrying capacity?
100
Human population size has ________ over time.
increased
100
The variety of different species that exist in a particular biological community is called ________
Species biodiversity
100
Give one example of a human activity that affects the atmsphere
Burning fossil fuels adds greenhouse gasses to the atmosphere and contributes to climate change.
200
When people exit or leave the country this is called ___________
Emigration
200
Exponential growth occurs when . . .
Organisms have unlimited resources and mates and limited competition and number of predators
200
Explain why families, historicaly, had more children on average than families in present day.
Death rates were higher so they needed to have more children to ensure some would survive.
200
Give an example of one way biodiversity benefits humans.
Earth’s best natural resources (wood, food, etc.)
Provides us with medicine and other valuable resources
Keeps ecosystems healthy and resilient (strong)
200
Explain how deforestation impacts biodiversity.
Deforestation destroys organisms habitat and threatens their survival.
300
Give an example of an ABIOTIC factor that limits population growth.
Temperature
Precipitation
Weather
pH
Salinity
Human disturbances
300
The most common kind of growth in stable ecosystems that is represented by an S-curve is called ____________ growth.
Logistic growth
300
What factors reduced death rates?
sanitation, healthcare advancements and medicine, improved nutrition
300
Give two examples of ecosystem services that are provided by ecosystems that are biodiverse.
Food production
Nutrient cycling and soil structure
Purifying water
Storing carbon
Regulating pests and pollinating crops
Buffering effects of extreme weather events
300
Describe how farmers can positively impact climate change and increase biodiversity.
Farmers can practice regenerative farming and plant many types of plants that can remove more CO2 from the atmosphere instead of planting large fields of a single crop. Farmers can also use low-till methods when plowing to improve soil quality.
400
Give an example of an BIOTIC factor that limits population growth.
Competition
Predation
Parasitism
Disease
400
The graph shown below is called a ___________ curve and represents _____________ growth.
J-curve; exponential growth
400
Explain the impact of the industrial revolution on the birthrate and deathrate of humans.
Humans continued to have a large number of children but the death rate decreased due to improved nutrition and medicine. As a result, the human population grew exponentially.
400
Explain the difference between species diversity and genetic diversity.
Species biodiversity is the number of different species in the biosphere.
Genetic diversity is the total of all the different forms of genes present in a particular species.
400
Explain the difference between bioaccumulation and biomagnification.
Bioaccumulation occurs when pollutants collect in the body tissues of organisms.
Biomagnification is a process in which pollutants are concentrated as the pollutants pass through trophic levels.
500
Populations can decrease in size if the death rate is greater than the birthrate OR . . .
Emigration is greater than immigration
500
Identify what each of the letters in the diagram represents:
A = J-curve/exponential growth
B = S-curve/logistic growth
C = carrying capacity
500
Describe how the human population growth curves changed as a result of the industrial revolution.
Human population growth was stable so resulted in an S-curve prior to the industrial revolution. After the industrial revolution the human population grew exponentially which resulted in a J-curve.
500
Explain how biodiversity makes an ecosystem more resilient. (HINT: Think about when you were each assigned a different tree and an insect affected only the Douglas fir trees in the forest.)
When ecosystems are biodiverse they are less likely to be severely impacted by limiting factors such as competition, diseases, etc.
500
Use the diagram below to help you explain why pregnant women are advised NOT to eat lots of tuna.
Biomagnification is a process in which pollutants are concentrated as the pollutants pass through trophic levels. The mercury is first absorbed by the water plants and then ingested by the small fish and then the larger fish like the tuna. As a result, there is lots of mercury in the tuna that can harm the growing baby if the mother eats too much tuna.