Question

Which process in photosynthesis uses energy from the sun?(1 point)
Responses

splitting water into hydrogen and oxygen

absorbing carbon dioxide

releasing oxygen

combining carbon dioxide and hydrogen

A scientist fills a glass container with water and places an aquatic plant inside the container, then closes the lid and places the container in direct sunlight. The scientist observes small bubbles on the surfaces of the plant’s leaves on days 1 and 2, but no bubbles on day 3. The scientist concludes that the bubbles were caused by photosynthesis. Which substance should be added to the water in order for the bubbles to reappear?(1 point)
Responses

glucose

carbon dioxide

oxygen

hydrogen gas

ATP is(1 point)
Responses

a form of energy that can be used and stored

a form of energy that cannot be stored

stored during cellular respiration

released when carbon dioxide and water form glucose

ATP stores some of the energy from glucose molecules during cellular respiration. How is the remaining energy from these glucose molecules released?(1 point)
Responses

Excess carbon dioxide

Excess water

Excess heat

Excess light

One molecule of glucose is recycled into ___Blank molecules of carbon dioxide during cellular respiration.(1 point)
Responses

12

2

6

1

Which role does photosynthesis play in the flow of energy? (1 point)
Responses

Photosynthesis converts radiant energy to chemical energy to be used by organisms in the food chain.

Photosynthesis provides radiant energy to all the organisms in the entire food chain.

Photosynthesis is how plants break down glucose to use for energy.

Photosynthesis allows plants to create energy for themselves to store and use for metabolism.

How does the carbon stored in the bodies of living organisms move into rocks?(1 point)
Responses

Carbon dioxide released through respiration dissolves in certain rocks, like limestone.

Living organisms decay, releasing carbon into the soil, and soil is compacted into rocks.

Living organisms decay and become fossils fuels, which eventually become rocks.

Carbon dioxide dissolves in ocean water and is slowly absorbed by rocks in the ocean.

The nitrogen cycle requires _____Blank to convert nitrogen to nitrites and nitrates.(1 point)
Responses

plants

bacteria

animals

legumes

Question
The three steps of the nitrogen cycle in order, starting with nitrogen gas in the atmosphere, are(1 point)
Responses

nitrogen fixation, nitrification, and denitrification.

denitrification, nitrification, and nitrogen fixation.

nitrification, nitrogen fixation, and denitrification.

nitrogen fixation, denitrification, and nitrification.

How do energy and matter move in ecosystems?(1 point)
Responses

Energy and matter cycle through the environment.

Energy and matter flow in one direction.

Energy flows in one direction, and matter cycles through the environment.

Matter flows in one direction, and energy cycles through the environment.

Which statement is true?(1 point)
Responses

Food webs are the best depictions of feeding relationships because they show many ways that plants and animals are connected.

Food chains are the best depictions of feeding relationships because they show many ways that plants and animals are connected.

Food webs are the best depictions of feeding relationships because they show a single path for the flow of energy through an ecosystem.

Food chains are the best depictions of feeding relationships because they show a simplified path for the flow of energy through an ecosystem.

In one or two sentences, explain how the chemical equation for cellular respiration shows that plants cycle matter. Include the numbers of molecules and atoms involved to support your explanation.(2 points) (write like a high schooler)


Question
In a food pyramid, there is typically less biomass at the top (i.e., there are very few individual tertiary consumers, whereas there are numerous individual producers). In three to five sentences, explain this phenomenon, citing evidence relating to energy flow and how plants support ecosystems.(4 points) (write like a high schooler)


Ocean ecosystems are sensitive to the chemical composition of the water. Any excess compounds can upset the balance and cause damage to organisms. In three to five sentences, describe how reducing consumption of fossil fuels can help the ocean ecosystem. (4 points) (write like a high schooler)

Answer 1

1) Which process in photosynthesis uses energy from the sun?
- splitting water into hydrogen and oxygen

2) Which substance should be added to the water so the bubbles (from photosynthesis) reappear?
- carbon dioxide

3) ATP is
- a form of energy that can be used and stored

4) ATP stores some energy from glucose during cellular respiration. How is the remaining energy released?
- excess heat

5) One molecule of glucose is recycled into ___ molecules of carbon dioxide during cellular respiration.
- 6

6) Which role does photosynthesis play in the flow of energy?
- Photosynthesis converts radiant energy to chemical energy to be used by organisms in the food chain.

7) How does the carbon stored in the bodies of living organisms move into rocks?
- Living organisms decay and become fossil fuels, which eventually become rocks.

8) The nitrogen cycle requires _____ to convert nitrogen to nitrites and nitrates.
- bacteria

9) The three steps of the nitrogen cycle in order, starting with nitrogen gas in the atmosphere, are
- nitrogen fixation, nitrification, and denitrification.

10) How do energy and matter move in ecosystems?
- Energy flows in one direction, and matter cycles through the environment.

11) Which statement is true?
- Food webs are the best depictions of feeding relationships because they show many ways that plants and animals are connected.

Short answers

12) Explain how the chemical equation for cellular respiration shows that plants cycle matter (1–2 sentences).
- The equation C6H12O6 + 6 O2 → 6 CO2 + 6 H2O shows one glucose molecule is broken down into six carbon dioxide and six water molecules, so the same atoms are just rearranged. This demonstrates that matter is conserved and recycled as plants and other organisms break down and release molecules back into the environment.

13) Why is there less biomass at the top of a food pyramid? (3–5 sentences)
- There is less biomass at the top because energy is lost at each trophic level, mostly as heat, so only a small fraction (about 10%) of the energy moves up to the next level. Producers (plants) capture energy from the sun and make lots of biomass, but when herbivores eat plants and carnivores eat herbivores, most energy is used for life processes and lost. Because less energy is available higher up, fewer organisms can be supported at the top levels, which is why tertiary consumers are rare compared to many producers.

14) How can reducing fossil fuel use help the ocean ecosystem? (3–5 sentences)
- Burning fossil fuels releases extra carbon dioxide, which the ocean absorbs and causes acidification that harms shell-forming organisms like corals and shellfish. It also contributes to global warming, which raises ocean temperatures and can create dead zones and stress marine life. By reducing fossil fuel use we lower CO2 emissions, slow acidification and warming, and help keep ocean chemistry and temperatures closer to conditions that marine organisms are adapted to.