5E Lesson Template. Source of the lesson:

Transcription

1 5E Lesson Template LESSON PLAN # Week 2_Lesson2_Days 4-5 ClassDay/Time Technology Lesson? Yes No (circle one) Author: Lauren Benoit Title of lesson: Energy Flow Length of lesson: 75 mins Description of the class: Name of course: Biology Grade level: High School Source of the lesson: TEKS addressed: (1) Scientific processes. The student, for at least 40% of instructional time, conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to: (A) demonstrate safe practices during field and laboratory investigations (2) Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is expected to: (A) plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology; (B) collect data and make measurements with precision; (C) organize, analyze, evaluate, make inferences, and predict trends from data; and (D) communicate valid conclusions. (9) Science concepts. The student knows metabolic processes and energy transfers that occur in living organisms. The student is expected to: (D) analyze the flow of matter and energy through different trophic levels and between organisms and the physical environment.

2 I. Overview Students will perform a calorimetry experiment to determine the number of calories in a nut. They will use their results to relate how energy is transferred through each trophic level in a food web. Students will also learn about the different organisms at each trophic level by understanding why there is a huge difference in population at each level. II. Performance or learner outcomes 1. SWBAT investigate energy flow throughout tropic levels 2. SWBAT explain why producers are important to the rest of the ecosystem III. Resources, materials and supplies needed Calorimeter (1 per group) One empty soda can with holes already poked in One empty coffee can with top already taken off Glass rod or wooden dowel cork needle or wire Graduated cylinders Distilled Water Thermometers (C) Safety goggles Lighter(s) Scale/Balance Cashews Calculators Copies of Procedure/Data Tables IV. Supplementary materials, handouts. (Also address any safety issues Concerning equipment used) Procedure/Data Tables, Project Notebook V. Safety Issues Adult supervision is required! As with any project involving open flame, there is a fire hazard with this project. Lab safety will be enforced. Long hair will be tied back and safety glasses will be worn. VI. Accommodations for learners with special needs (ELLs, Special Ed, 504, G&T) ELL: Students do hands on activities arranged in groups of three to four, so that they could learn new vocabulary and ways of describing things from one another. Pictorial representations are available for students about Energy Flow experiment as listed in Dong, We will try to focus mainly on student-student interaction, and keep lecturing to a minimum. When questioning the students, we will try to promote students speaking up even if they are not sure of the right words to describe something. By focusing on group learning and going around to each group to talk one on one with students, we will try to make sure everyone was moving forward and understanding new concepts. Students who may need more help (dyslexic or ELL) can be given a handout to read the day before this lesson. The worksheet should include background on the subject,

3 pictures to illustrate what the experiment entails, and words that will be used in the lesson. Content of this worksheet is to be determined by the teacher based on the individual needs of the student.

4 Five-E Organization Teacher Does Probing Questions Student Does Engage (5 minutes) So I have to write a research paper for class and one of the requirements is for me to write down the number of different species at each trophic level. Ok. After each group has come to the board and written their thoughts, I will tell them that I really don t need to know this for my research paper. I will then show my results. Plants: ~280,000 Rabbits: ~50 Lions: 1 Humans: 1 How many types of plants do you think are present in the world? Rabbits? Lions? Humans? (I will ask students to get into their groups and discuss amongst their selves) Do you see any trend with the different types of species at each trophic level? [miss I don t know. I think there is 10,000 different types of plants, 3,000 different types of rabbits, 500 different types of lions, and 1 type of human] [Yes, the higher the trophic level, the lower the numbers!] That is correct. Do you know why that may be? (Hint: we talked about this yesterday and the beginning of the week) Where do we get our energy from? [Oh yeah, because higher the trophic level, the lower amount of energy] [food!]

5 Right. We get our energy from food. Do you know how much energy is in the different types of food we eat? [no] Well we are going to find out today in our experiment. Exploration (50 minutes): Today we are going to figure out how much energy is in cashews. Each group will do their own test. Ask students to read over experiment with their group. Energy in food is contained in bonds that hold atoms and molecules together. So why do you think we have to burn the cashews in the experiment? Let me ask this question, where do you think energy exist in foods? So how do you think we can release that energy? [I don t know miss] [I don t know miss] [we burn the food] Right. We cant break in half because there would not be enough energy released to measure. When burning the cashew, we are breaking all bonds and releasing a lot of energy. Enough so that we can measure the amount. Why cant we just break the cashew in half aren t we breaking bonds when we do that? [I don t know miss]

6 This type of experiment is called a calorimetry. The apparatus for the calorimetry is in front of you. Calories are used to tell us how much energy is in something. The definition of a calorie is the amount of energy required to raise the temperature of one gram of water 1 degree Celsius. How do you think we are going to measure the energy? What do you normally find at the top of the nutrition box on the back of most food items? [I don t know miss] [ummm, how many calories is in the food] So we are going to burn the nut, so that energy is released. We are going to measure that energy by how much the water temperature changed. So looking at your sheet this is why we have an initial temperature of water and a final temperature of the water. We also have an initial mass of the nut and a final mass of the nut. Right so follow you instructions given to you and collect your data. Please remember the safety rules that are involved with this experiment. Don t play with fire, and make sure that your safety goggles are on at all time. If lab safety is not followed point will be deducted Why do you think we have to figure out the mass of the nut before and after the burning? [so that we can get an idea of how much energy the nut released based on the mass]

7 from grade. Explain (10 minutes): After students finish getting data, each group will come to the board and write down their findings so a class average can be made after calculations. Students will be asked to copy this data down. Now that you all have got your results, we need to calculate how many calories were burned. On the next page of you procedure sheet is a formula. Right so the Q stands for calories. So our m stands for our mass of water, our c is specific gravity of water which was not found in this experiment, it is 1 cal/g C, and our change in Temperature is our final temperature minus the What do you think the Q stands for? What were we trying to find in our experiment? How do we measure energy? What other data did we get our of our experiment? [I don t know miss] [amount of energy is in the cashew] [by calories] [we got the mass of the nut before and after burning, we got the initial and final temperature and the mass of the water]

8 initial temp. I will then do a sample calculation on the board so they can see how the calculation looks and so students with special needs can have a visual aid of the calculation. Next, I will ask students to do calculations within their groups, when they are finish, they will come up to the board and write down their answers so a class average can be calculated. Elaboration(10 minutes) This experiment was done to day to show how energy moves throughout trophic levels of a food chain or web. In Biology, energy flow from trophic levels is related to something called the 10% rule. At each trophic level energy is lost by 10 percent. So lets review, who is normally at the bottom of the food chain? Why are they at the bottom? What is another word that we call them besides plants? [plants] [They are called primary producers, this is why they are located at the bottom because they basically start the food chain] Do plants create their own [They create their own

9 Right, through the process of photosynthesis, plants create their own energy by way of the sunlight. Plants start off with energy of 100 percent. Because they make their own energy. A nut is a plant. Through our calculations we got the number of Calories that were burned off by the nut and its energy percentage is 100. Don t get your percentages and calorie count confused. Right. Right. So lets look at our calculation sheet and compute our data for the 10 percent rule. Within you groups, calculate how much energy in Calories each trophic level will have based on the food chain given. Students will come up and write their answers on the board after they finish. I energy or do they have to get it from eating something else? Through what process? So if plants produce their own energy, how much energy do plants start off with? So if a rabbit were to eat the nut, how much percent of energy would be lose? And what if a deer at the rabbit how much more percent of energy will be lost? sunlight] [photosynthesis] [I don t know] [10 percent] [10 percent]

10 feel like this method allows students to help their peers so that no one is left behind and so that they wont be embarrassed if they don t get the right answer on the first try. So why isn t there a lot of energy left when you get to the top of the food chain? [because its been taken all by other animals in the food chain due to the 10 percent rule] Right. Good job. Evaluation (5 minutes): Students will clean up and get ready for dismissal. Go over homework assignment. Students will write a lab report of their findings. A detailed handout will be given because I know that I will be short on time. If the students have any questions they will be able to me. Exit Ticket: How does this data relate to your findings about the amount of calories found throughout each trophic

11 level? Procedure 1. Calorimeter will already be set up for experiment. 2. Using your graduated cylinder, measure enough water so that the soda can be half-filled. First weigh a clean beaker. Using graduated cylinder pour water into beaker and then weigh again. Subtract mass of beaker from mass of water and beaker. Record mass of water in data table. 3. Pour water in soda can. 4. Weigh the cashew. Record mass of cashew in data in table. 5. Weigh needle. Record mass of needle in data in table. 6. Measure the initial temperature (T (initial)) of the water. 7. Place nut on needle. 8. Place needle/nut vertically into top of cork. 9. Place cork/needle/nut upright at the bottom of the coffee can 10. Light the nut on fire. 11. Once the nut has caught a flame (this may take a while) place soda can apparatus over the flame. 12. Once the nut has stopped burning, measure the final temperature of the water, T (final). Record final temperature in data table. 13. Determine the new mass of the nut by placing the nut and needle on the balance together. Record mass of nut/needle after burning in data table. 14. Subtract the mass of the needle. Record mass of nut after burning in data table. Data Page

12 Mass of water (g) Mass of nut before burning (g) Mass of needle (g) Initial Temperature (C) Final Temperature (C) Mass of nut and needle after burning (g) Mass of nut after burning (g) Calories amount Q water = mc T Q water is the heat captured, in calories (cal); m is the mass of the water, in grams (g); c is the specific heat capacity of water, which is 1 cal/g C (1 calorie per gram per degree Celsius); and T is the change in temperature (the final temperature of the water minus the initial temperature of the water), in degrees Celsius ( C). Calculations: Q water =

13 Your Group Calorie Amount Group from class Group from Class Group from Class Average Calorie Amount Following Energy Through the Food Chain: Energy amount in Percentage Nut ( Primary Producer) Rabbit (Primary Consumer) Lion (Secondary Consumer) Human (Tertiary Consumer) Energy amount in Calories