Science Ideas Come in Different Sizes Dr Art Photosynthesis

How do plants get energy?

Developed past Chantier 7 projection team members

Instructional goals:

Students will be able to:

1. Depict the phenomena of transpiration, photosynthesis and cellular respiration
2. Illustrate the relationship between light and photosynthesis (i.e., yous need light source for plants to grow; more than low-cal more photosynthesis)
three. Illustrate the human relationship between carbon dioxide and photosynthesis
4. Assemble bear witness of inputs and outputs of photosynthesis

Grade level: Grade 7, 8

Duration: 50-150 minutes depending on activities chosen (3-4 periods of 75 minutes)

Instructional Materials: Whiteboard (or smart lath, black board) for creating public record for students' thinking. For the materials needed for specific activities, please see below:

Activity #one: An Oxygen Manufacturing plant

• Plants (both aquatic and terrestrial plants)
• Plastic bag or plastic wrap
• Terrarium or 2L plastic canteen
• Flask
• 500ml or 1L beaker
• Water
• Desk Lamp

Action #2: Lite! Lite! (Optional)

• Whatever submersed aquatic plant that is in proficient wellness and appears capable of photosynthetic activeness (i.e., non stale or wilted). (eastward.1000.,  Canadian waterweed (Elodea canadensis) or coontail (Ceratophyllum demersum)) – you lot can buy waterweed from any pet shop where they sell fish/aquarium supplies
• Glass test tubes (20 × 150 mm)
• Racks to hold test tubes
• A calorie-free source (e.one thousand., desk lamp)
• Big to medium sized drinking straws
• Thermometer

Activity #three: More Carbon Dioxide (Optional)

• Elodea, an aquatic plant available at many pet or gardening stores
• Bromothymol blue solution (acid-base indicator available for purchase online.  Xanthous pH less than half dozen.0, blueish pH above seven.half-dozen)
• Lights with clamp attachment
• Test tubes (ane for each colour and two additional every bit controls)
• Plastic wrap
• Aluminum foil

Worksheet: Please see appendices.

QEP POLs for secondary cycle one relevant to the concept of photosynthesis:

Simple school:

Students explain the essential needs of living organisms (e.g. food, respiration) and describe metabolic activity (transformation of energy, growth, maintenance of systems and torso temperature). They describe the function of photosynthesis, which they distinguish from respiration.

Secondary bike 1:

​​Names the inputs and outputs involved in photosynthesis.
Names the inputs and outputs involved in respiration.

Children'southward preconceptions relevant to the concept of photosynthesis:

• There is no difference between respiration and breathing.
• The main component of air is oxygen.
• There is no oxygen in exhaled air.
• Lighting a candle in a sealed jar with water proves that air is 21% oxygen (the h2o moves up the jar because the 21 % oxygen is consumed).
• All essential components for plants are captivated from the soil via rots.
• Roots supply plants with energy.
• The sun keeps plants warm, and and so they grow better.
• Plants jiff. They inhale carbon dioxide, and they breathe oxygen.
• Plants go energy straight from the dominicus.

(Adjusted from: https://scienceinquirer.wikispaces.com/file/view/RespirationCorr.pdf)

Assessment Items to explore or uncover students' preconceptions effectually the concept of photosynthesis:

Question 1. Which of the post-obit is TRUE about the carbohydrate molecules in plants?
A. The sugar molecules come from the soil.
B. The sugar molecules are the result of a chemic reaction.
C. The carbohydrate molecules are one of many sources of food for plants.
D. The sugar molecules are fabricated from molecules of h2o and minerals.

(Retrieved from AAAS Item ME095005, http://cess.aaas.org/items/ME095005#/0)

Question 2. Where does the food that a constitute needs come from?
A. The food comes in from the soil through the plant's roots.
B. The food comes in from the air through the plant's leaves.
C. The found makes its food from carbon dioxide and water.
D. The found makes its food from minerals and h2o.

  (Retrieved from AAAS Item ME029006, http://cess.aaas.org/items/ME029006#/0)

Questiom three. What is True about the inside of a plant cell?
A. The inside of a plant cell is completely solid.
B. The inside of a institute cell is completely filled with air.
C. The inside of a plant cell is completely filled with liquid water.
D. The within of a constitute jail cell contains liquid water and solid structures.

(Retrieved from AAAS Item CE065001, http://assessment.aaas.org/items/CE065001#/0)

Description of the Lesson:

The goal of this lesson is for students to (1) engage in experiments that enable students to assemble show of inputs and outputs of photosynthesis, (2) understand the relationship betwixt light and photosynthesis, and (three) empathize the human relationship between carbon dioxide and photosynthesis. This lesson program includes the following steps:

Step 1: Introduction – Engage Students in Learning: In this step, instructor introduces the driving question of this lesson: "Plants demand energy to stay alive and grow. How do you recall plants get energy?"

Step ii: Groundwork Noesis Probes (BKPs): In this step, teacher use the assessments listed above to elicit students' prior agreement and ideas of photosynthesis.

Footstep 3: Collecting and Making Sense of Data: In this pace, teacher will conduct the Activity #1 – An Oxygen Factory. Teachers will and so choose one of the selection activities (i.e., Activity Option #2 – Light! Calorie-free! or Activity Option #3 – Role of Carbon Dioxide and Calorie-free) to provide students with more evidences for the upcoming discussion at the end of the lesson. While students are engaging in these activities, teacher tin ask give-and-take questions to rails students' understanding of the concept. Students are too invited to record their observation on the worksheet given.

Pace 4: Developing Evidence-Based Explanations: Following the activities, teacher engages in this footstep by inviting students to share their data with other groups and the whole class. Teacher may also post summary data on a class summary chart on the lath.

Step 5: Evaluation: Teacher can assess students' learning outcomes past choosing i of the mail service-assessment strategies: (i) Question and Answer/Exit Cards; (two) Create a multimedia affiche; (3) Using the cess questions listed above.

Details and procedures of each step are explained every bit follow:

Footstep 1 of The Lesson: Introduction – Engage Students in Learning

In Pace i, teacher will help students to connect the idea of nutrient-web with photosynthesis. The goal of this step is to innovate the important role of photosynthesis plays in our ecosystem.

(1)  Introduction of the topic by maxim: "Hello, we are going to learn about photosynthesis today. Before starting the lesson, does there anyone know where plants become their free energy from?"

(ii)  Teacher can prepare a feed-spider web (encounter Figure 1.) on transparency, doc cam, computer screen, or draw the figure on the lath. Instructor can than ask the following questions to guide the word:

• All living things demand energy to survive. How do us, man get energy?
• From this food-web effigy (Figure ane), how exercise fox and rabbits proceeds their energy from?
• From this food-web figure (Figure i), how practice grass and trees proceeds their energy from? Exercise grass and trees 'eat' whatever other organisms?

Effigy one. Food-web
(Figure retrieved from MOSART Life Science Survey Exam, Particular form # 921, Q8)

(3)  Based on students' response, teacher can re-voice students' responses and write the responses on the board.

(four)  After students sharing their ideas nigh food-web, teacher can brainstorm the class by introducing the driving question of this lesson: "Plants need free energy to stay alive and grow. How do you recall plants get energy?"

Step 2 of The Lesson: Background Knowledge Probes (BKPs) - Eliciting Pupil Thinking

The goal of this step is to arm-twist students' prior understanding and ideas of the topic without evaluating their response or correcting their answers at this point.

(ane) Administrate the musical instrument: To help teachers determine effective starting points for the students and to get to know students' background cognition, skills, attitudes, experience and motivation, before starting the lesson, y'all can administrate the 3 assessment question provided above, in order to uncover students' preconceptions effectually the concept of photosynthesis.

Teacher can use clickers to obtain students' responses. If the school does non take clickers, teacher can ask the questions to the whole class and enquire students to heighten their hands for the respond. If at that place is no respond from students, teachers can besides ask students to write their answer on a piece of newspaper and put them in a box. Teacher will and then write some response on a board (or a chart paper) for discussion.

(2) Pressing for explanations: Later on administering the test, teacher tin share the data with students and inquire students for the explanations. You lot may re-vox their explanations and write their response on a board. For case, teacher can ask: "We see that many of you choose option C as an respond. Does anybody want to share why they chose selection C? What is your evidence for proverb that?"

(3) Introducing the term: Teacher can use the term "photosynthesis" to further probe students' prior understanding. Teacher will then start the lesson past asking students what they think "photosynthesis" ways and write down their responses on the board (or a nautical chart paper).

Stride iii of the Lesson: Collecting and Making Sense of Data

The goal of this step is to help students to (one) develop their questions and/or predictions to learn more nigh the topic, and (2) examination their predictions through hands-on inquiries, challenges, problems.

Instructor will first conduct the Action #i – An Oxygen Factory. Afterward, teachers can choose ane of the choice activities (i.eastward., Action Selection #2 – Light! Lite! or Activity Pick #iii – Function of Carbon Dioxide and Low-cal) to provide students with more than evidences for the upcoming word at the end of the lesson. These optional activities could assist instructor to engage in ongoing, formative assessments to rail students' learning (e.g., walking around class to listen to their ideas, recording and displaying their ideas, observations, worksheets, student journals, students' work products, etc.).

Details and procedures of each activity are explained as follow:

Activity #one: An Oxygen Factory

Office one: Training: Teacher volition take 2 different demo stations (i.e., Demo Station #1–Photosynthesis of an aquatic plant and Demo Station #2–Growth factors of a plant) prepared at least three days prior to the action. Both teachers and students can create the demo stations.

Demo Station #1: Photosynthesis of an aquatic establish:

(1)  Identify a submersed aquatic plant (eastward.m., Canadian waterweed (Elodea canadensis) or coontail (Ceratophyllum demersum) in a flask.
(2)  Fill a 500mL or 1L chalice with h2o.
(3)  Place the flask (with aquatic plants) into the beaker. Make sure that the aquatic plants are submerged in water.
(4)  Identify a light source (east.yard., desk lamp) near the beaker.

Demo Station #2: Growth factors of a plant:

(i)  Prepare 3 different pots of plants that are the aforementioned size (relevantly same size).
(2)  Prepare three terrariums (or 2 Liter soft drink bottles with the superlative cutting off and saved for hat) with soil and ane constitute.
(3)  Terrarium 1: Add some oxygen gas, and seal the terrarium (or bottle lid). Characterization the terrarium.
Note: If you do not have access to oxygen gas, just seal the terrarium. Make sure the establish had been in a closed system at least for iii days.
(iv)  Terrarium 2: Add some carbon dioxide gas, and seal the terrarium (or lid for the bottle.) Label the terrarium.
Note: If you do non have access to carbon dioxide gas, identify alkalizer in h2o, in an erlenmyer flask with a 1-hole stopper, an elbow tube and glass tubing. Insert the tubing into the lid of the terrarium equally the carbon dioxide is being produced).
(5)  Terrarium 3: The third terrarium is a control. Leave the plant in an unsealed terrarium.

Role ii: Ascertainment: Students find the plants at the two demo stations (i.e., Demo Station #1–Photosynthesis of an aquatic constitute and Demo Station #2–Growth factors of a plant). Instructor can enquire questions to arm-twist students' ideas.

For example, for the Demo Station #1, instructor tin can ask the follow questions:

• What exercise you think is beingness produced in the flask?
• What is the show for this: Oxygen is being produced.
• The flask is foggy Inside. Why?"

For the Demo Station #2, teacher can ask the follow questions:

• What do you detect in the three terrariums?
• Where practise you think the bubble comes from in the second terrarium?
• What gas do you lot think the bubbles are?
• What is happening in the tertiary terrarium? Explain.
• What differences do you see betwixt the first and second terrarium?"

Part 3: Recording observation: Instructor will ask students to observe the three dissimilar terrariums and write down their observation on their worksheet (Appendix A).
Note: The following Activity #2 and #iii are optional. These optional activities would allow teachers to help students collect more than testify/data for the final discussions at the end of the lesson.

Action Option #2 – Light! Calorie-free!

The goal of this action is to illustrate the causal human relationship between light and photosynthesis (i.due east., more than light, more photosynthetic activity). Part one: Preparation: (one) Label ii test tubes as either a treatment grouping or a control grouping. An hour or more before class, place a 5-cm segment of an aquatic found into each handling examination tube. Annotation : Control test tubes are necessary to demonstrate that, with the combination of low-cal and associated heat, bubbles may form at the surrogate's surface, but few, if any, of those b ubbles will be released from the surrogate and ascension to the surface of the water. (2) In separate test tubes, place an inert object similar in dimension to the plant segments (e.chiliad., a 5-cm section of a drinking harbinger). The exam tubes with these constitute surrogates act as controls. If multiple plant species are bachelor, add together an additional exam tube for each boosted species and identify 5-cm cuttings of those species into their ain test tubes. Teachers should attempt to have all establish clippings be as similar equally possible (i.e., taken from the aforementioned location on the stalk of multiple plants). (3) Fill all test tubes with the same amount of tap water, to within 2 cm of the superlative. Note : If multiple lamps and test tube racks are available, this experiment can exist replicated past splitting the course into groups of three or four and carrying out the same measurements at each station. Part 2: Activity: (one)Pass out the test tubes with plant segments to students. Students may work in a pair or groups. (2) Lead a discussion to allow students to empathise that the charge per unit of chimera formation is a measure of the rate of photosynthesis. Teacher may inquire: Where does the bubble come from? What exercise you think the bubbles are made of? Are they oxygen? Carbon dioxide? (iii) Place all tubes at a specified altitude from a calorie-free source and permit xv minutes for the plant to acclimate to the new surroundings. Brand sure to plan for enough test tubes to carry out this experiment using multiple distances. (east.1000., 15, 30, and 45 cm from the lite source). (iv)  Afterwards the examination tubes containing plants or plant surrogates (e.one thousand., straws) have been exposed to the light for at to the lowest degree xv min, ask students to count the number of bubbling that sally from the found and float to the surface and mensurate the temperature in all tubes at the same time they count the number of bubbling. Notation: Because the command tubes will collect bubbles, it is important for students to count simply the number of bubbling that come from the plant or plant surrogate that rise to the surface. On the ground of the rate of bubble production observed, students should determine over what period of fourth dimension (e.grand., 15, thirty, or sixty south) chimera production should be measured; the greater the bubble production, the less time necessary. Note : Increases in temperature can influence rates of photosynthesis and have been implicated in the spontaneous generation of bubbles from nonphotosynthetic materials. (5)  Enquire students to construct a graph based on their data and write downward their ascertainment and caption .

Activeness Pick #three – Role of Carbon Dioxide and Light

(one) Set the lamps at least several feet apart and abroad from windows. (ii) Pour equal amounts of bromothymol blueish into the test tubes or glasses (about 2/three of the test tube or ½ cup in a small glass). Annotation : If you lot do non take enough solution, you may dilute it with a niggling water. Merely be certain to employ distilled water and dilute the entire supply but slightly. (3)  Cutting equal-sized pieces of elodea for each test tube or glass (most 3 inches in length). Place a piece of elodea in each examination tube or drinking glass. Record the initial color of the bromothymol blueish solution. Have students to characterization three test tubes (due east.m., #1, 2, and iii). Talk about the part of bromothymol blueish (pH indicator) by maxim: " If the solution is blue, information technology is alkaline (basic). If the solution is yellow, information technology is acidic. If there is photosynthesis occurring, the indicator changes its colour from blue to yellow (Base–blueish, neutral (pH range 6.0-7.6)–green, Acid–xanthous). The reason for this colour change is that the carbon dioxide released during photosynthesis reacts with the h2o to course carbonic acid ." (4)  Have students to blow through a harbinger into the exam tube #1; Cover the test tube (aluminum foil works well). Be sure to completely seal the vessel to continue gas from entering or leaving. Note : Every bit they add together Carbon dioxide into the tube, the bromothymol blue solution will change its color to yellow (acidic). (5)  Accept students to cover the test tube #2 completely with aluminum foil to block out any low-cal. Test tube #3 is a control, so it should be left uncovered. (6)  Take students to write a hypothesis to explain which test-tube the solution will change colour, and to what colour. Instructor can ask: "Which test tube will have well-nigh photosynthetic activity? and Why?" (7) Place the test tubes under the lamp. The plants should all be 12 inches (30 cm) away from their lamp. (eight) Permit the test tubes sit for a one-hour to 24 hours. Record the final color of the solution for each exam tube. (nine)  Ask students to create a bar graph to illustrate their results. Inquire students to compare their results with their hypothesis. Annotation : Instructor tin have a course discussion to share their data.

Step 4 of the Lesson: Developing Bear witness-Based Explanations

The goal of this pace is to assist students in irresolute their preconceptions through developing circuitous evidence-based explanations later on their investigations in lite of the data they gathered in the above activities. Instructor can ask students to share their data with other groups. Instructor may likewise post summary data on a class summary chart on the lath.

(i)  Divide students into groups. (Groups of ii-iii). Ask students to reply the questions on the worksheet (Appendix B). For instance:

• Where does the water that appears on the side of the terrariums (Action 1 – An Oxygen Factory) come up from?
• Which conditions are necessary for bubbles to appear in the water (Activity 2 – Low-cal! Light!)?
• Which gas in the atmosphere encourages plant growth?

Facilitate the word as teacher walk around the classroom.
Note: The important aspect here is that you allow students to make connection betwixt prove/information provided from the activities and their explanations for their answer.

(2)  Once students are finished with the worksheet, facilitate a grade discussion. Teacher can lead a give-and-take virtually the similarities and differences in the group analysis.
Note: Teacher may go over the questions with students and have them present their answers and explanations. Or, teacher may ask students to present their data to the balance of class while teacher write down similarities and differences emerging from dissimilar groups' data.

(3)  Go back to the driving question on the lath: "Plants need energy to stay alive and grow. How do you lot call back plants go energy?" Ask students if their view have changed and enquire why. Again, encourage students to draw their explanations from the evidence/data from the activities. Teacher tin can use the post-obit strategies:

Ø Orienting students to each other's thinking: For example, teacher tin ask: Practice y'all hold with what Student A said? and Why?
Ø Pressing for caption: For example, teacher tin can ask: Group A and B, both of you found results/information that are dissimilar than your previous predictions. Why exercise you lot think so?

Note: If fourth dimension allows, you can show your students "photosynthesis song": this video summarizes the process of photosynthesis, offering visual and musical sources: https://world wide web.youtube.com/sentry?five=C1_uez5WX1ohttps://world wide web.youtube.com/lookout?v=C1_uez5WX1o

Step 5 of the Lesson: Evaluation

Three strategies can exist used to practise a postal service-cess; they are:

Selection #1: Question and Answer/Exit Cards: Have students to make full out the worksheet page individually (come across Appendix). Subsequently students fill out most part of the worksheet, ask them to discuss in a small-scale group (3-4 students). Teacher tin can facilitate the group word while walking around the classroom by asking questions such equally: "With regards to Input and its origin: Why do you think so? What prove exercise you have from the activities we have done in course?" After going of worksheet page. 100 together, teacher may give the assessment items tested in the showtime and/or accept them write exit cards (i.e., write a curt reflection on what they learned and what they still unsure virtually).

Option #2: Create a multimedia affiche: By creating a multimedia affiche on what students take learned in lessons, they can depict various ways of representing ideas (due east.m., write summaries of the facts, create visual arts, add sound). This volition be done as a group project. As a group, students accept another opportunity to hash out about their understandings on photosynthesis with their peers in informal ways. Specific steps are describe as follow:

(ane)  In a group of 3-4, students will brand a multi-media poster. The poster should represent their understanding of photosynthesis using multi-media of their choice (e.g., podcast, songs, YouTube, visual arts etc.). Students tin draw from already existing sources (e.thousand., song from YouTube, pictures from encyclopedia).

(2)  Ask students to connect what they find in their daily life to the concept of photosynthesis.

(3)  In their everyday life (east.g., dwelling, school garden, or on the way to school), students tin can accept a photo, brand a collage, or draw a painting to connect the concept of photosynthesis to a moment in their daily life.

(4)  With the photograph/collage/drawing, students are instructed to write a short essay or record a podcast that explains how their photograph/collage/drawing (e.grand., photos of flowers, collages of cows eating grass, cooking meals) relates to the concept of photosynthesis.

For instance, a group of students may write: "The meals we eat are the products of photosynthesis. Vegetables grow considering of photosynthesis. Meat is a product of animals eating producers or other consumers. Energy from photosynthesis is transferred to the consumer. Humans eat both vegetables and meat which are both products of photosynthesis."

(5)  Teachers give specific guidelines and rubrics for students to follow. It is important for students to include the following key points in their short essays:

• The procedure of photosynthesis;
• Inputs and outputs of photosynthesis;
• Factors influencing the photosynthesis and the connection with their daily life experience.

(6)  Afterward the completion of the multimedia posters, form can have a symposium, where students will have an opportunity to present their multimedia posters to other students in the classroom.

Option #3: Cess question: administer the same question and to see if students' responses had been modify. Teacher can apply the clickers to obtain students' responses. If the school does non take clickers, teacher tin can ask the questions to the whole form and ask students to heighten their easily for the answer. If there is no answer from students, teachers can also enquire students to write their answer on a piece of newspaper and put them in a box. Teacher will so write some response on a board (or a chart paper) for give-and-take.
Note: You may re-vocalisation their explanations and write their response on a board.

This lesson programme is inspired by the post-obit sources:
Education.com: http://www.education.com/pdf/photosynthesis-of-elodea/
Eureka!: Science and Technology, Secondary Bike Ane; Student Textbook B (Activity viii: An Oxygen Factory, pp. 36-37); Worksheet (U1 38, U1 39); Educational activity Resource Guide, Volume 1 (p.53).
Ray, A. M., & Beardsley, P. M. (2008). Overcoming pupil misconceptions nigh photosynthesis: A model-and enquiry-based approach using aquatic plants. Science Activities: Classroom Projects and Curriculum Ideas, 45(1), 13–22.

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Source: https://www.mcgill.ca/sciedchantier7/resources/sample-lesson-plans/photosynthesis

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