Photosynthesis Inputs Outputs
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Middle School Life Science › Photosynthesis Inputs Outputs
Scenario (Error detection): Photosynthesis involves inputs and outputs of matter. A student says, “I can tell inputs and outputs just by memorizing the words, not by the arrows.”
Model description: Into leaf arrows labeled “carbon dioxide (matter)” and “water (matter)”. Out of leaf arrows labeled “oxygen (matter)” and “sugar/food (matter stored)”. Into leaf arrow labeled “sunlight (energy)”.
What evidence in the model best identifies an output of matter?
The fact that plants grow larger over time
The idea that outputs are always wastes
The arrow pointing into the leaf labeled “sunlight (energy)”
The arrow pointing out of the leaf labeled “oxygen (matter)”
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that outputs can be identified without arrows, but arrow direction is key. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Error detection): Photosynthesis involves inputs and outputs of matter. A student draws a model with arrows and labels.
Student’s model description: Arrow into leaf labeled “oxygen (matter)”. Arrow into leaf labeled “water (matter)”. Arrow out of leaf labeled “carbon dioxide (matter)”. Arrow out of leaf labeled “sugar/food (matter)”. Separate arrow into leaf labeled “sunlight (energy)”.
Which part of the student’s model is an error when identifying inputs and outputs of matter for photosynthesis?
Labeling oxygen as matter
Showing sunlight as energy entering the leaf
Showing sugar/food leaving the leaf as matter stored in the plant
Showing oxygen entering the leaf as an input of photosynthesis
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that oxygen is an input, but it is actually an output of matter leaving the leaf. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Prediction if an input is missing): Photosynthesis involves inputs and outputs of matter. Use the model’s matter arrows.
Model description: Matter inputs into leaf: “water” and “carbon dioxide”. Matter outputs: “oxygen” to the air and “sugar/food” to the plant. Energy input: “sunlight (energy)”.
If a plant has plenty of sunlight but its roots cannot take in water, which matter output shown in the model would decrease because photosynthesis would slow down?
Soil nutrients leaving the leaf
Sunlight entering the leaf
Oxygen leaving the leaf
Oxygen entering the leaf
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that missing water only affects sugar, but it reduces oxygen output too. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Model interpretation): Photosynthesis involves inputs and outputs of matter. Study the model and use the arrow directions.
Model description: A plant leaf is shown. Arrows labeled “carbon dioxide (matter)” and “water (matter)” point into the leaf. An arrow labeled “sugar/food (matter stored in plant)” points from the leaf to the rest of the plant. An arrow labeled “oxygen (matter)” points out to the air. A separate arrow labeled “sunlight (energy)” points into the leaf.
Which label is an output of photosynthesis (matter leaving the leaf) according to the model?
Oxygen
Water
Sunlight
Carbon dioxide
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that oxygen is an input, but it is actually an output of matter leaving the leaf. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Claim evaluation): Photosynthesis involves inputs and outputs of matter, and the model uses arrows to show matter entering and leaving.
Model description: Arrow into leaf: “carbon dioxide (matter)”. Arrow into leaf: “water (matter)”. Arrow out of leaf: “oxygen (matter)”. Arrow from leaf to plant body: “sugar/food (matter stored)”. Separate arrow into leaf: “sunlight (energy)”.
Which claim about photosynthesis is incorrect based on the model?
Water is an input of matter because it enters the leaf.
Oxygen is an output of matter because it leaves the leaf.
Sunlight is a matter input because it enters the leaf.
Carbon dioxide is an input of matter because it enters the leaf.
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that sunlight is a matter input, but it is actually an energy input, not matter. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Prediction if an input is missing): Photosynthesis involves inputs and outputs of matter. Use the model’s arrows.
Model description: Matter inputs into leaf: “carbon dioxide” and “water”. Matter outputs from leaf: “oxygen” and “sugar/food (stored in plant)”. Energy input: “sunlight (energy)”.
If the plant cannot get carbon dioxide from the air, which output of matter shown in the model would decrease the most?
Sunlight entering the leaf
Water entering the leaf
Soil entering the leaf
Oxygen leaving the leaf
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that missing an input like carbon dioxide only affects sugar, but it reduces outputs like oxygen too. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Input-output identification): The model shows that photosynthesis involves inputs and outputs of matter. Use the arrows and labels to decide what is an input or output.
In the model, arrows labeled “carbon dioxide (matter)” and “water (matter)” point into the leaf. An arrow labeled “oxygen (matter)” points out of the leaf. A separate arrow labeled “sunlight (energy)” points into the leaf.
Which substance is an input of photosynthesis (matter entering) in this model?
Carbon dioxide
Sunlight
Soil nutrients
Oxygen
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that soil nutrients are a primary matter input, but the model emphasizes carbon dioxide and water as key matter inputs. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Model interpretation): Photosynthesis involves inputs and outputs of matter. The model uses arrows to show matter flow.
Model description: A box labeled “Leaf (photosynthesis)” has arrows:
- Into the box: “carbon dioxide (matter)”, “water (matter)”
- Out of the box: “oxygen (matter)”, “sugar/food (matter stored in plant)”
- Into the box (separate style): “sunlight (energy)”.
Which statement is supported by the model about matter?
Carbon dioxide is an input of matter because the arrow shows it entering the leaf.
Oxygen is an input because it is needed to start photosynthesis.
The plant’s matter comes only from the soil because soil is an input.
Sunlight is an output of matter because it leaves the leaf after photosynthesis.
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that soil is the main matter source, but models show carbon dioxide as a key input. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Claim evaluation): Photosynthesis involves inputs and outputs of matter. Use the model to judge a claim.
Model description: Into leaf: “carbon dioxide (matter)”, “water (matter)”. Out of leaf: “oxygen (matter)”. From leaf to plant: “sugar/food (matter stored)”. Into leaf: “sunlight (energy)”.
Which claim is unsupported by the model?
Oxygen is produced and leaves the leaf as matter.
Water is an input of matter entering the leaf.
Carbon dioxide is an input of matter entering the leaf.
The plant creates new matter from nothing during photosynthesis.
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that plants create matter from nothing, but matter is conserved from inputs. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.
Scenario (Input-output identification): Photosynthesis involves inputs and outputs of matter. Use the model’s labels to separate matter from energy.
Model description: Into leaf: “water (matter)”, “carbon dioxide (matter)”. Out of leaf: “oxygen (matter)”. From leaf to stem: “sugar/food (matter stored)”. Into leaf: “sunlight (energy)”.
Which item in the model is energy rather than matter?
Sugar/food
Water
Sunlight
Oxygen
Explanation
The core skill is identifying the inputs and outputs of matter in the process of photosynthesis. Photosynthesis has matter inputs like carbon dioxide and water that enter the plant, and matter outputs like oxygen and sugar that are produced and leave or are stored. Models show these flows using arrows pointing into the leaf for inputs and out of the leaf for outputs, often labeling matter and energy separately. A checking strategy is to follow the arrow directions and labels to confirm if a substance is matter entering or leaving. A common misconception is that sunlight is matter, but it is labeled as energy in models. Through photosynthesis, plants move matter from the environment into their structures for growth. This process incorporates external matter into organisms, enabling energy storage and biomass increase.