Photosynthesis 101
What is the process plants use to make their own food using light energy?
Photosynthesis
What do plant roots absorb from the ground that is needed for photosynthesis?
Water.
What food substance do plants produce during photosynthesis?
Sugar (glucose).
A plant in full sunlight produces 30 oxygen bubbles, while one in dim light produces 10. Which is photosynthesizing faster?
The plant in full sunlight.
Which gas released by plants during photosynthesis is used by animals for respiration?
Oxygen.
What is the original source of energy used by most plants to make food?
The Sun (light energy)
Which gas do plants take in from the atmosphere to make food?
Carbon dioxide.
What gas do plants release during photosynthesis?
Oxygen.
Three identical plants receive different amounts of sunlight. What is the independent variable?
The amount of sunlight.
Which gas released by animals during respiration can plants use during photosynthesis?
Carbon dioxide.
Name the two materials plants use during photosynthesis to make sugar.
Water and carbon dioxide
True or false: Plants obtain most of the material they need for growth from soil.
False. Most of their growth materials come from air and water.
How does the food produced by photosynthesis help a plant grow?
It provides stored chemical energy and materials used for growth and other life processes.
A plant receives no sunlight and produces no oxygen bubbles during a test. What conclusion does this evidence support?
Light is needed for photosynthesis to produce oxygen.
In a terrarium containing a plant and a grasshopper, what process allows the plant to release oxygen when light is available?
Photosynthesis.
What two substances are produced during photosynthesis?
Sugar and oxygen
A plant grows without soil in water containing dissolved nutrients. What does this demonstrate about soil?
Soil is not essential for making the plant's food or providing most of its mass. Plants can obtain water and minerals without soil.
How can a plant continue growing at night without sunlight?
It uses stored food for energy and growth when photosynthesis cannot occur.
Plant A grows 8 cm in full light, Plant B grows 4 cm in partial light, and Plant C grows 1 cm in darkness. Which plant had the greatest growth and why?
Plant A. Its greater access to light supported photosynthesis and growth.
Explain how plants and animals participate in the exchange of oxygen and carbon dioxide.
Plants use carbon dioxide and release oxygen during photosynthesis. Animals use oxygen and release carbon dioxide during respiration.
Explain why sunlight is necessary for photosynthesis but is not itself a material that becomes part of the plant.
Sunlight supplies energy to make sugar from carbon dioxide and water. It does not supply matter to build the plant.
A plant gains 100 grams of mass, but its dry soil loses only 2 grams. What does this evidence suggest?
Most of the plant's increased mass did not come from the soil. Air and water supplied much of the matter.
A student says that plants absorb sugar from the soil to grow. Explain why this is incorrect.
Plants make their own sugar through photosynthesis using carbon dioxide, water, and light energy.
A student tests whether sunlight affects plant growth. Name TWO conditions that should be kept the same for all the plants.
Any two: plant species, starting size, amount of water, soil type, container size, or air conditions.
A plant and an animal are kept in a transparent, sealed terrarium. Explain why both light and a balance of living things matter for the system to survive.
Light supports photosynthesis, which produces food and oxygen. Both plants and animals respire, so oxygen production and consumption must remain balanced, along with other survival needs.