Cycles of Matter/Energy
Which process adds carbon dioxide to the atmosphere in the carbon cycle?
A. Photosynthesis in plants
B. Nitrogen fixation by bacteria
C. Cellular respiration in organisms
D. Phosphorus uptake by plant roots
What is C. Cellular respiration in organisms?
All organisms do cellular respiration. The end products of cellular respiration are CO2, H2O, and ATP.
Write the chemical formula for photosynthesis. Include the words under the formula
CO2 + H2O + Sunlight --> C6H12O6 + O2
Carbon dioxide + water + sunlight (solar energy) -->glucose + oxygen
In an energy pyramid, which trophic level has the greatest amount of available energy?
A. Tertiary consumers
B. Secondary consumers
C. Primary consumers
D. Producers
What is D. Producers.
Producers have the greatest amount of available energy because they can make their own through photosynthesis.
Which pair describes a predator–prey relationship that could help maintain stability in an ecosystem?
A. Two species of birds sharing the same nesting site
B. Wolves hunting elk in a forest
C. Two plant species using the same nutrients
D. Bacteria decomposing fallen leaves
What is B. Wolves hunting elk in a forest
The predator (hunter) is the wolf
The prey (hunted) is the elk
The definition of biodiversity.
Biodiversity is a variety of life forms.
The more biodiversity the healthier an ecosystem is
The claim about matter and energy in ecosystems that is correct?
A. Both matter and energy are recycled indefinitely.
B. Matter flows one way and energy cycles.
C. Matter cycles, but energy flows in one direction and is lost as heat.
D. Neither matter nor energy can leave an ecosystem.
What is C. Matter cycles, but energy flows in one direction and is lost as heat?
Remember the 10% rule of available energy in an ecosystem (only 10%) will move on to the next trophic level.
Write the chemical formula for cellular respiration and label the formula with words
C6H12O6 + O2 --> ATP + CO2 + H2O
glucose + oxygen --> ATP + carbon dioxide + water
(3 minutes) Plants, foxes, fungi, and rabbits are in an ecosystem. Identify the niche (role) or each group (producer, consumer type, decomposer) by creating a food chain and labeling the niches.
Plants --> rabbits --> foxes --> fungi
Producer --> Primary Consumer --> Secondary Consumer --> Decomposer
A river ecosystem experiences several years of severe drought. Which statement best predicts the combined effects on carrying capacity and biodiversity?
A. Carrying capacity and biodiversity both increase as water becomes scarce.
B. Carrying capacity decreases, and some species may disappear from the area.
C. Carrying capacity stays the same, but biodiversity always increases.
D. Both carrying capacity and biodiversity remain unchanged.
What is B. Carrying capacity decreases, and some species may disappear from the area?
Biodiversity is a variety of different species. Carrying capacity is how many organisms of a specific species an ecosystem can sustainably support.
Which human activity is most directly linked to a decrease in biodiversity in a forest ecosystem?
A. Planting native trees along streams
B. Building many roads and neighborhoods in the area
C. Setting aside land as a wildlife refuge
D. Using drip irrigation to conserve water
What is B. Building many roads and neighborhoods in the area?
The statement to best describe the role of bacteria that fix nitrogen in an ecosystem.
A. They convert carbon dioxide into glucose for producers
B. They change nitrogen gas into forms plants can use in the soil.
C. They break down rock to form new soil
D. They release oxygen into the atmosphere through photosynthesis
What is B. They change nitrogen gas into forms plants can use in the soil?
This process is called Nitrogen Fixation. It accounts for 90% of the nitrogen in an ecosystem.
State the two types of cellular respiration and one difference between them.
Aerobic Respiration: uses oxygen + glucose to create ATP, will happen in the mitochondria
Anaerobic Respiration: uses NO Oxygen only glucose to create ATP, will happen in the cytoplasm
In a food chain: grass → grasshopper → frog → snake → hawk. If a disease greatly reduces the frog population, what is the most likely effect?
A. The snake population increases because there is more food.
B. The grasshopper population decreases due to less food.
C. The grasshopper population increases because fewer are eaten.
D. The hawk population decreases because it has less prey.
What is C. The grasshopper population increases because fewer are eaten?
Remember when answer the question to choose the most immediate effect.
Which situation is most likely to cause a population to level off and form a logistic growth curve instead of continuing exponential growth?
A. Unlimited food and space
B. No predators and no disease
C. Increase in available nesting sites
D. Decrease in food supply and space
What is D. Decrease in food supply and space?
Exponential growth is a constant increase
Logistic growth is an "s" shape
A town wants to reduce air pollution and protect local ecosystems. Which solution best balances benefits and sustainability?
A. Building more coal‑powered plants for cheap electricity
B. Encouraging public transportation and solar energy use
C. Spraying more pesticides to protect crops
D. Allowing unlimited logging to increase jobs
What is B. Encouraging public transportation and solar energy use?
(3 minutes) Compare the roles of a producer and a decomposer in the carbon cycle. How does each affect the amount of carbon in the atmosphere or in the soil?
What is the producer will reduce atmospheric CO2 through photosynthesis and decomposers will release CO2 into the atmosphere through respiration while breaking down dead matter (return nutrients to soil?
The cellular location of photosynthesis and cellular respiration.
Photosynthesis will occur in the chloroplasts of plant cells
Cellular respiration will occur in the mitochondria of animal and plant cells.
If 10,000 kcal of energy is available in the producers of a grassland, which is the best estimate of energy available to primary consumers?
A. 100 kcal
B. 1,000 kcal
C. 10 kcal
D. 10,000 kcal
What is B. 1,000 kcal
Remember only 10% moves onto the next trophic level.
*Move the decimal point one place.
Which graph pattern would best represent a population that has reached the carrying capacity of its environment?
A. A line that keeps increasing steeply
B. A line that increases, overshoots, then levels off with small ups and downs
C. A straight horizontal line at zero
D. A line that drops steadily to zero
What is B. A line that increases, overshoots, then levels off with small ups and downs.
Which example best shows a positive human action that helps maintain the cycling of matter and energy in a damaged grassland ecosystem?
A. Introducing non‑native grasses that grow faster
B. Overgrazing by livestock to keep grass short
C. Reseeding native plants and limiting grazing in some areas
D. Spraying herbicides to remove all plant species
What is C. Reseeding native plants and limiting grazing in some areas?
(3 minutes) Describe the role of plants in the phosphorus cycle and explain why this roles is important for other organisms in the ecosystem.
What is plants absorb phosphorus from the soil through roots allowing it to move through the food chain/web when consumed by another organism?
(3 minutes) Explain how photosynthesis and cellular respiration work together to move carbon through an ecosystem. In your answer, include the terms producers and consumers.
Photosynthesis done by producers will pull CO2 out of the atmosphere. When plants (producers are eaten) any carbon remaining in the plant will move onto the consumer that ate it. Consumers will breathe in oxygen and through cellular respiration will create CO2, ATP, and water. The CO2 is not necessary for consumers they will breathe it out and in the atmosphere it will be recycled by the producers when they do photosynthesis.
(3 minutes) A pond ecosystem receives the same amount of sunlight each year. Explain why there are fewer top predators than herbivores in this ecosystem, using the 10% rule in your explanation.
Herbivores eat plants. There will be more plants (producers) than consumers because they have more access to energy. Herbivores will then be the greatest in number after plants because they have more available food and therefore more energy compared to Carnivores who need to consume herbivores and/or other carnivores to get energy.
A graph shows a deer population rising quickly, then flattening out around 600 individuals.
a) Identify the carrying capacity for this population.
b) Describe two possible limiting factors that could keep the population near that level.
What is the carrying capacity of 600?
Need one net positive and one net negative limiting factor.
Possible limiting factors: predators, drought, food stores (increase/decrease), weather conditions, mate potential (increase/decrease)
(3 minutes) You are given a graph showing the number of bird species in a wetland before and after a restoration project. Explain how you would use this data to argue whether the restoration improved biodiversity and ecosystem health.
The graphs shows in a increase in the number of bird species after the restoration project. This means an increase in biodiversity (variety of organisms) happened, the greater the biodiversity the healthier the ecosystem.