Populations

Example

Population

Group of organisms of the same species.

Multiple Choice

An example of a population is...

• all trees in a forest

• all plants in a forest

• all animals in a forest

• all maple trees in a forest

Terms used to describe a population

Population size

​The number of organisms in a population

Population density

the number of individuals of the same species that live in a given unit of area.

Population Dispersion

Pattern of distribution of organisms in a population.

Multiple Choice

The density of a population is ___.

• the number of individuals born every year

• the proportion of males and females

• the number of individuals living in cities

• the number of individuals per unit area

Immigration

Moving to live permanently in a foreign country.

Emigration

Leaving one's own country to settle permanently in another.

Multiple Choice

Which two factors can increase the size of a population?

• birth rate and emigration

• birth rate and immigration

• death rate and emigration

• death rate and immigration

Multiple Choice

Which of the following would most likely cause a decrease in population size?

• emigration and increased birth rate

• emigration and increased death rate

• immigration and increased death rate

• immigration and increased death rate

On a population graph, the carrying capacity is represented by a flat line

• May also be a small "wave"

• Follows a period of exponential growth; a J-shaped curve where the population keeps increasing

• The line represents population size, so it decreases in response to a limiting factor

Multiple Choice

Carrying capacity is...

• The maximum number of individuals that can fit into an area

• The greatest # of individuals an area can support over time.

• Ability of an area to accommodate a growing population

• The maximum number of species that can co-exist in an area

Multiple Choice

A population always stays exactly at its carrying capacity.

• True

• False

Multiple Choice

What happens if a population grows past its carrying capacity?

• The population keeps growing

• The population starts to die off

• The entire species will go extinct

• The carrying capacity just increases

Multiple Choice

Which graph depicts exponential growth in a population?

Multiple Choice

What is the carrying capacity of the graph?

• around 500

• more than 800

• less than 300

• around 700

Multiple Choice

What point on the graph represents the carrying capacity?

• A

• B

• C

• D

Multiple Choice

What type of growth is represented behind?

• exponential

• logistics

• a good kind

• representative

Multiple Choice

What is the carrying capacity for this sheep population?

• 1.8 million

• 1.25 million

• 1.6 million

• 1.o million

Multiple Choice

Logistic growth has 3 phases. In Phase 1, the population grows rapidly. In Phase 2, population grows slowly. In Phase 3, growth stops. What causes growth to stop in the 3rd phase of logistic growth?

• Emigration

• Immigration

• Exponential Growth

• Carrying Capacity

Multiple Choice

What type of growth model is shown in image A?

• Exponential

• Logistic

Multiple Choice

which statement sounds accurate based on the graph data. 

• The zebra and lions do not affect each other
• when lions population increases, so does the zebra population
• When the zebra population increases, it causes the lion population to also increase
• when zebra populations go down, the zebra population goes up. 

Multiple Choice

Which kind of growth does the human population follow? It is described as a J-shaped curve.

• Exponential Growth

• Logistic Growth

• Outstanding Growth

• Minimal Growth

Limiting factors are any factor that reduces or the size of a population or keeps it from increasing

• May be a resource, another species, the environment, etc.

• Example: food is a limiting factor because you can't have more individuals than food to feed them

Limiting factors that DO NOT depend on population size are called density-independent

• Include climate, weather, natural disasters, and pollution

• Affect all populations the same, whether they are large or small

Limiting factors whose effect depends on the size of the population are called density-dependent

• Includes natural resources (food, water, space), diseases, and predators

• Tend to have a greater effect on large, dense populations because of increased competition and more opportunity to attract predators and disease

Multiple Choice

An environmental factor such as storms and extreme heat or cold that decrease a population are considered to be -

• density-dependent factor

• population density

• dispersion

• density-independent factor

Multiple Choice

This may cause a population to increase

• increase of food supply

• removal of predators

• removal of disease

• all of these

Multiple Choice

Something that regulates the size of a population is called...

• a limiting measure

• a limiting factor

• carrying capacity

• biodiversity

Multiple Choice

If a disease destroying barley plants in a field swept through an ecosystem, what would happen to the barley eating bird population in the the field ?

• The bird population would stay the same
• The bird population would infinitely increase
• The bird population would decrease

Multiple Select

Which of the following are examples of a density independent factors?

• forest fire

• seasonal cycles

• storms

• disease

Multiple Select

Which of the following are density dependent factors?

• competition for resources

• predation

• disease

• natural disasters

Multiple Choice

Any thing or organism that regulates the size of a population of another organism is known as __________.

• a limiting measure

• a limiting factor

• factorization

• materialization of precipitation

Multiple Choice

Can two different species occupy the same habitat and have the same niche?

• Yes! Many species do this easily!

• Yes, but with accommodations to share resources.

• No, this never happens.

Fill in the Blanks

If two different species occupy the same habitat and share the same ecological niche,

would occur.

Keystone Species

A keystone species is an organism that helps define an entire ecosystem. 

Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.

The removal of a keystone species REDUCES the BIODIVERSITY of the ecosystem.

Keystone Examples

The keystone species in this habitat is the sea otter.

The sea otter eat urchins and therefore keep the population of sea urchins low. Sea otters also build dams which create wetlands for other organisms to live in.

Without sea otters, sea urchins over populate and eat all of the kelp. Wetlands are destroyed and biodiversity decreases.

Multiple Choice

Which of the following parts of a community helps hold the food web together and has a disproportionate impact on ecosystem compared to the number of organisms present?

• keystone species

• dominant species

• foundation species

• endangered species

Multiple Choice

the variety of life in the world or in a particular habitat or ecosystem

• biodiversity

• demography

• carrying capacity

• poaching

Multiple Choice

Why are some sharks considered a keystone species?

• Because they are a top predator

• They scare off smaller fish that may overgraze an area of sea grass

• They are tertiary consumers

• They are cartilaginous

Multiple Choice

Why are bees considered a keystone species?

• The honey they make supports the bear population

• They pollinate flowers that produce fruit which supports the ecosystem

• They sting when threatened

• They live in hives

Multiple Choice

What is a keystone species?

• A species that helps to hold an ecosystem together

• A species that lives in or around rocks

• Keys and stones have nothing to do with ecology

• A keystone isn't a living thing, it's just a stone

Multiple Choice

A species form that supports an entire ecosystem.

• Keystone Species

• Herbivores

• Umbrella Species

• Predators

Invasive Species

• Invasive species, or a species that causes harm to a new environment. 

• Invasive species have traits that give them a competitive advantage over native species.

• Invasive species can directly (prey on native species) or indirectly (change food webs) impact native species.

Invasive Species Examples

• The zebra mussel  was carried to the Great Lakes in the mid-1980s from Eastern Europe in ships. 

• They have become  invasive species whose growth produces huge populations.

• They upset aquatic food webs, filtering so much plankton from the water that some native fishes and shellfish starve.  

Invasive Species Examples

• Cane Toads are native to Central and South America.

• Cane Toads were introduced to Australia and other countries to control insects (beetles) that damaged sugar cane plantations.

• The poisonous toads have caused severe damage to local wildlife wherever they were introduced.

Multiple Choice

What is a native specie?

• A specie that is local and has lived in the same place
• A specie who has come from another state or country
• A specie that has no "home" and travels for its whole life
• None of the above

Multiple Choice

1. What makes a species invasive?

• Moving to a new ecosystem and taking resources from natives 
• Not having papers
• Species that can't adapt
• Plants that take up too much space

Multiple Choice

When taken to a new habitat, non-native plants often threaten native plants of the new habitat. Why do they do this?

• Non-native plants are able to mutate rapidly

• Non-native plants cause native animals to relocate

• Non-native plants are able to be used for medicine

• Non-native plants compete with native plants for resources

Biodiversity

The variety of plants and animals and other living things in a particular area or region.

Also means the number, or abundance of different species living within a particular region

• High biodiversity - Many plants and animals in an area.

• Low biodiversity - Low amount of plants and animals in an area​

​

​Some text here about the topic of discussion.

Biodiversity

Multiple Choice

We live in a desert. What type of biodiversity do we have here?

• High biodiversity

• Low biodiversity

Multiple Choice

How do you know we have low biodiversity?

• We have a lot of different types of plants and animals

• We have a low amount of different types of plants and animals

• We have a lot of people who live in Las Vegas

• Nothing grows here

Poll

What else could low biodiversity mean?

• The organisms that live here suffer

• Our ecosystem is healthy and can recover from disruption quickly

• A disruption to our ecosystem won't recover as quickly

• Disruptions happen all the time and can easily be fixed

​High - Many variations in DNA between members of the same species

Low - Few variations in DNA between members of the same species​

Genetic Diversity

​High - Many type of different species in the same area

Low - Few types of different species in the same area ​

Species Diversity

High - Many types of habitats for organisms to live

Low - Few types of habitats for organisms to live​

Ecosystem Diversity

​

Multiple Choice

This is an example of

• High species diversity

• Low species diversity

• High genetic diversity

• High ecosystem diversity

What can genetic diversity protect against?

Genetic Diversity

The more variation in DNA between members in a species, the more protections they have from changes to their environment. ​

​

​In this picture, the brown fish and the green fish has the highest genetic diversity. If water oxygen changes, they have the best chance at surviving.

​Different DNA means some organisms have the ability to fight disease better.

Disease

​As environments change, some organisms will be able to adapt to their new environment easier

Climate Change​

​

​Different DNA means some organisms will be able to survive their predators better.

Predator Survivability

Before the industrial revolution, most moths were white and speckled black. Only some were black

1848

This white and black speckles gave them camoflauge on trees

​​1848

As the Britshed burned coal, their buildings and trees turned black and so did the moths.

​​1900

Why did the white ones start to disappear?

​​1900

​Black Peppered Moth

Multiple Choice

Why did the white ones start to disappear?

• The coal turned the white moths black

• They are actually different species and the white ones went extinct

• The white ones got a disease that the black ones didn't

• Predators ate the white ones at a higher rate.

​The Importance of Biodiversity

• Biodiversity is essential to supporting and enhancing life on Earth. 

• Humans depend on resources and other benefits provided by diversity. 

• There are economic reasons for preserving biodiversity.

• A healthy biosphere provides many services to humans and other organisms. 

• For example plants provide oxygen and remove carbon dioxide. 

• Healthy ecosystems can also provide protection from floods and drought and regulate local climates.

Indirect Economic Value

Humans depend on plants and animals to provide food, clothing, energy, medicine, and shelter.

Direct Economic Value

​The Importance of Biodiversity

Risk to Biodiversity

• Habitat Loss and Change

• Invasive Species

• Pollution

• Overharvesting

• Climate Change

Drag and Drop

​ Which ecosystem has the MOST biodiversity​ ​

Placeholder

Drag these tiles and drop them in the correct blank above

deserts

oceans

tundras

tropical rainforest

Multiple Choice

Which of the following is NOT a threat to biodiversity?

• pollution

• planting trees

• overhunting or fishing

• habitat destruction

• introduction of invasive species