Ecology Unit Key points and practice

STANDARDS:
SB5. Obtain, evaluate, and communicate information to assess the interdependence of all organisms on one another and their environment.

a. Plan and carry out investigations and analyze data to support explanations about factors affecting biodiversity and populations in ecosystems.
b. Develop and use models to analyze the cycling of matter and flow of energy within ecosystems through the processes of photosynthesis and respiration.
c. Construct an argument to predict the impact of environmental change on the stability of an ecosystem.
d. Design a solution to reduce the impact of a human activity on the environment.
e. Construct explanations that predict an organism’s ability to survive within changing environmental limits.

Unit 1: Ecology

Ecosystems are interconnecting systems that include biotic communities and abiotic components. All ecosystems have carrying capacities (limits) on the number of organisms it can support. Organisms have defined niches (roles) in an ecosystem.

Nutrient and energy cycles connect all organisms to biotic and abiotic factors within an ecosystem. Any change (disturbance) can affect the stability of an ecosystem. Disturbances are caused naturally or by human activity and affect the equilibrium of the ecosystem.

Match

Match the following

• Individual

• Group of the same species

• Collection of populations interacting with each other

• All the biotic and abiotic factors of an area

• Group of ecosystems in the same area

Organism

Population

Community

Ecosystem

Biome

• Organism

• Population

• Community

• Ecosystem

• Biome

Ecologists describe an ecosystem by its size, density or distribution of resources. Populations are affected by migration, births and deaths.

Populations increase and decrease due to limiting factors. Density dependent limiting factors are biotic factors such as food, predation and disease. Density independent limiting factors are typically abiotic factors that include weather, natural disasters and human activities.

Multiple Choice

parasites, disease, predators, are examples of what type of limiting factors?

• density dependent

• density independent

• survivorship

• type 1 curve

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

A lion and a cheetah attempt to occupy the same niche. The more aggressive lion survives; the cheetah does not.

• Density-Dependent: Competition

• Density-Independent: Competition

• Density-Dependent: Predator-Prey

• Density-Independent: Predator-Prey

Multiple Choice

A group of elephants gets stuck in mud at the edge of the river from a recent mud slide. A lion waits for an elephant to get tired before it attacks. What is the limiting factor to the elephant population?

• Predator-Prey Relationships

• Natural Disaster

• Herbivory Effect

• Competition

Multiple Choice

Two arctic fox are fighting with a polar bear for a sea lion carcass. One fox distracts the bear while the other eats. What type of limiting factor is the polar bear?

• Predator-Prey Relationships

• Competition

• Herbivory Effect

• Weather

Carrying capacity is the maximum number of organisms that the environment can support. Carrying capacities can change over time due to changes in limiting factors.

Multiple Choice

What type of growth is this graph representing

• Logistical Growth

• Exponential Growth

Multiple Choice

What type of growth is this graph representing?

• Logistical Growth

• Exponential Growth

Multiple Choice

In the graph to the right, what is the population of deer at the carrying capacity of the environment?

• 3

• 7

• 70

• 40

Multiple Choice

When a specific population grows past the ecosystem's carrying capacity, what happens to the population?

• Density Independent limiting factors start to occur resulting in the population going farther above carrying capacity.

• Density Dependent limiting factors start to occur resulting in the population going back below carrying capacity.

• The population will go extinct due to lack of resources

• The population grows then finds a new carrying capacity

Multiple Choice

What is the carrying capacity of the graph?

• around 500
• more than 500
• less than 500
• around 600

Multiple Choice

What point on the graph represents the carrying capacity?

• A
• B
• C
• D

Multiple Choice

What will happen if all of the frogs in a population die?

• The frogs' predators will decrease and the frogs' prey will increase

• The frogs' predators will increase and the frogs' prey will decrease

• We better all pray because there isn't anymore frogs.

Biodiversity is the measure of the different types of life in an ecosystem. The variety of species is essential for ensuring a healthy ecosystem. The more biodiversity, the more resilience.

Fluctuations in one specie's population can impact others within an ecosystem. A keystone species is a species that if removed has a SIGNIFICANT impact on the entire ecosystem.

Multiple Choice

Species richness is

• a measure of how all of the individual organisms in an ecosystem are balanced between the different species.

• the total number of different species found in an ecosystem

Multiple Choice

Which island would be the most biodiverse?

• Small island far from the mainland

• Small island close to the mainland

• Large island close to the mainland

• Large island far from the mainland

Multiple Choice

Why is biodiversity in an ecosystem so important?

• Because it can help humans where to determine good places to develop farm land.

• Because places that have a healthy biodiversity are unaffected by major disturbances.

• Because having a high biodiversity allows ecosystems to withstand major changes.

• Because having a high biodiversity allows for fewer opportunities of competition for similar resources.

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

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

Based on the graph shown, how can you tell sea otters are a keystone species?

• as the sea otter population decreases, biodiversity increases
• as sea otter population increases, biodiversity increases
• changes in the sea otter population have little effect on biodiversity 
• the sea otter population dereases due to the presence of urchins

All living things need energy for life processes. Energy is constantly flowing through ecosystems through food chains. The sun gives energy to producers (autotrophs) to perform photosynthesis. Consumers (heterotrophs) eat either the producers or other consumers, thus passing energy and matter throughout an ecosystem.

Remember the law of conservation states that matter and energy can not be created or destroyed. So matter and energy is transferred from one form to another though out the ecosystem.

The levels in a food chain a re called trophic levels. Arrows link organisms together and show the energy flow. There is a loss of energy at each trophic level. As an organism processes food, heat is lost as a by product.

To access this energy, organisms use a process called respiration. Respiration is a chemical reaction that breaks down food to release stored energy. ALL living tings perform cellular respiration to obtain ATP (energy) necessary for cellular functions.

Multiple Choice

How much energy is available to be passed on to the next trophic level in an ecosystem?

• 100%
• 10%
• 50%
• 75%

Multiple Choice

In the energy pyramid here, how much of the energy in each level gets lost as heat or used by the organism for survival?

• 80%
• 90%
• 10%
• 20%

Multiple Choice

The diagram represents a pyramid of energy in an ecosystem.  Which level would most likely contain members of the plant kingdom?

• A
• B
• C
• D

Multiple Choice

What trophic level has the most energy?

• Autotrophs
• Heterotrophs
• Omnivores
• Consumers

Multiple Choice

In the energy pyramid below, which organism has the least amount of energy available?

• Producers
• Herbivores
• Carnivores
• Top Predator

Multiple Choice

For an energy pyramid, the 10% rule states that

• 10% of the energy is transferred from one organism to the next.

• 10% of the energy is gained.

• 10% of the animals will starve.

• 10% of the producers are eaten.

Multiple Choice

A food pyramid represent the relative amount of energy in trophic levels. Which of the following correctly shows a food pyramid?

• A
• B
• C
• D

Food webs show the feeding relationships between all organisms in an ecosystem. Each food web is made of multiple food chains.

As you consume food, your body reduces the food to elements and energy. The elements are cycled through the biogeochemical cycles. There are 5 major elements of life. These are Carbon, Hydrogen, Oxygen, Nitrogen and Phosphorus.

Carbon and oxygen are found in the atmosphere, rocks and organisms. It is mainly cycled using cellular respiration and photosynthesis. Human activities can affect the levels of carbon dioxide.

Nitrogen enters food chains through plants who fix nitrogen into a usable form. Nitrogen is then used to create proteins and DNA. Animals consume nitrogen by eating. When organisms die, nitrogen is released back into the environment.

Phosphorus enters the food web through plants and enters animals through consumption. Phosphorus is needed to create DNA.

Multiple Choice

How does carbon dioxide return to the atmosphere?

• Photosynthesis

• Combustion and Cellular Respiration

• Consumption

• Decomposition

Multiple Choice

Which one of these is not considered a biological process?

• Nitrogen Fixation by bacteria

• Consumption by animals

• Elimination of Waste by animals

• Erosion

Multiple Choice

What is the main thing that carries out Nitrogen Fixation?

• Lightning

• Bacteria

• Plants

• Humans

Multiple Choice

How do non-human living things participate in the nitrogen cycle? (fill in the blank/short answer)

• Bacteria decompose organic matter (decomposition)

• animals move nitrogen during consumption

• Bacteria convert waste into ammonia (ammonification)

• All of the above

Multiple Select

How do humans negatively affect the nitrogen cycle ?

• Use too much fertilizers causing an imbalance in soil.

• Combustion- releasing N into the atmosphere

• Eating plants

• Planting trees

Ecological succession is the sequence of changes in an ecosystem over time.

Primary succession occurs after a disturbance leaves bare rock. Examples would be volcanic eruption, pavement or glacier melt.

Secondary succession occurs when there is already soil, but the ecosystem ahs a major disturbance. Examples, fire, tornado, hurricane.

Explanation Slide...

​

Match

Match the following

Primary succession

pioneer species

abiotic factor

secondary sucession

climax community

• Primary succession

• pioneer species

• abiotic factor

• secondary sucession

• climax community

Multiple Choice

What is the main difference between primary and secondary ecological succession?

• Primary begins WITHOUT soil; Secondary begins WITH soil

• Primary is the first state and secondary is the second stage

• Primary builds plant community; secondary builds animal community.

• Primary begins WITH soil; Secondary begins WITHOUT soil

Multiple Choice

After a volcanic eruption, volcanic rock is present (but no soil). Which of the following states the most likely order of succession that would be seen?

• Lichens → Shrubs → Grasses → Trees

• Lichens → tree → shrubs→Grasses

• Grasses → Lichens → Shrubs → Trees

• Lichens → Grasses → Shrubs → Trees

Match

Match the following

• Biomass

• Species richness

• Complexity

• Dynamic Equilibrium

• Biodiversity

the total amount of living tissue in a trophic level.

All the populations of all the different species that live together in a particular area

the state or quality of being intricate or complicated

a state of balance between continuing processes

the variety of organisms in an area, by species, genes, populations, and communities

• the total amount of living tissue in a trophic level.

• All the populations of all the different species that live together in a particular area

• the state or quality of being intricate or complicated

• a state of balance between continuing processes

• the variety of organisms in an area, by species, genes, populations, and communities

Multiple Choice

What is the order of succession shown in this figure?

• A, B, C, D
• B, A, D, C
• C, D, A, B
• D, A, B, C

Many factors affect an organism's ability to survive changes within the environment. Adaptations are part of what assists organisms in surviving their changing environments. However, when an environment changes drastically, the adaptations may no longer keep them alive.

Each species can only tolerate a range of factors, and if the range changes, their population will change. Other conditions that influence survival include temperature, rainfall, sunlight, salinity, acidity and human impacts.

Multiple Choice

Many common products, such as wooden furniture, paper, and books, are made from trees. Which of the following is a likely consequence of humans cutting down a forest in order to make use of the natural resources there? 

• the decrease of chemical runoff into the oceans
• increased acid rain
• the increase of light pollution in cities
• the destruction of habitats

Multiple Choice

Human activities that degrade ecosystems result in a loss of diversity of the living and nonliving environment.  Two ways in which humans frequently harm ecosystems and affect other organisms is through land use and pollution.

How does land use cause a reduction in biodiversity? 

• It decreases the space and resources available to certain species
• It causes herbivores to become carnivorous
• It provides a more hospitable living environment
• It causes all the natural Earth cycles to stop

Multiple Choice

Loggerhead sea turtles are large turtles that live in the ocean and nest on the Florida coast. The female loggerhead sea turtle lays more than 100 eggs in the beach sand. How is laying so many eggs an important adaptation that helps these turtles to survive?

• Large nests of eggs help keep the eggs warm enough to allow more turtles to hatch.

• If many turtles hatch, they can help defend each other against predators in large numbers.

• The more eggs that are laid, the greater the chance that more turtles will live to become adults.

• A large number of eggs in one place makes it possible for the mother to lie on the eggs until they hatch.

Multiple Choice

Hurricane Andrew caused many animals in the Miami Zoo to become displaced. Two of the animals that lost their homes were the collared lemming which has thick white fur and sharp claws, and the other was a marsh rabbit that has thin brown fur and is a strong swimmer.

If both were thought to have sought refuge in a Florida forest, which one would have a better chance of survival and why?

• The marsh rabbit because its ability to swim helps it to scare away predators.

• The collared lemming because its sharp claws help it grip the ice when walking.

• The collared lemming because its thick, white fur helps it stay warm during the winter months.

• The marsh rabbit because its thin, brown fur helps it blend into its environment and stay cool.