February 10, 2016 Lesson Plan # 3 Science 8-B & 8-C I. Objectives: At the end of the lesson, the students will be able to: a. ; b.; and c. Learning Competency: II. Subject Matter: A. Topic: Digestive System: Digestion Process Part 1 B. Reference: Science Learners Manual. Campo et.al, Vibal Publishing House, Inc pg. 291 Page Keeley’s Uncovering Student Ideas in Science,Vol. 4, pg.131 C. Materials: laptop, DLP/projector “Parts of the Digestive System Cards”, cracker, tissue paper, iodine solution, teaspoons, long thin balloons, cooking oil, medicine dropper/pipette, white bread, zip lock baggies III. Teaching Procedure: Teacher’s Activity
Learner’s Activity
A. Preliminary Activities Greetings Prayers Checking of Attendance Classroom Management B. Review Let’s have a recap in our previous Sir! We discussed about the impacts lesson. What was our lesson last of human activities in the ecosystem. meeting? Very Good! Kindly give some human activities that affect the ecosystem?
Sir! Monoculture. This is a cultivation of a single crop in large areas. By limiting the cultivation of different kinds of plants, people also deprived many animals of their food and home.
That’s right! In addition to that, only the insect pests that eat the monocrop remain in the area and if uncontrolled, these pests can totally wipe out the monocrop in Sir! The use of herbicides and insecticides. Farmers spray their crops a short time. with insecticides to kill pests, and with herbicides to kill weeds. However, the What else? chemicals also destroy other organisms including beneficial insects
and soil organisms which help in decay. Very Good! Many insect pests become resistant to chemicals which may lead to the use of increased amount of pesticide. C. Motivation Create a list in your notebooks consisting of your favorite lunch foods. (Encourage students to share their list with a lab partner.) Sir! Sir! When you eat these foods, what Sir! organs of your body are involved? Sir! Sir! Sir!
Mouth Esophagus Stomach Small Intestines Large Intestines Colon
Very Good! All your answers are Sir! Digestive System. correct! What system do these organs belong? Exactly! Today we discussing about system.
will be digestive
It turns food into “poop”; stomach acid dissolves food.
D. Developmental Activities What do you know about the digestive system? Let the students go their group mates in Science. Distribute a set of “Digestive System Organ/Structure Cards” to each group.
(Place cards in order, then check with the list on the board; make any necessary adjustments on the order: ) Teeth/mouth Esophagus Stomach Ask students to place these cards Small intestine Large intestine in order that food would travel Colon through the digestive system, starting with the mouth.
Determine which functions go with each organ/structure of the digestive system.
All of you are correct! Now, distribute the set of “Digestive System Function Cards” to each group.
Use the following AT stems for discussion:
Write “Accountable Talk Stems” (ATS) on the board for students to use for their discussion: I think this goes with _____because _______. I disagree because_____________________. I agree because _______________________.
I think this goes with ________because _________. I disagree because ______________________. I agree because __________________________. (Students have varied ideas) By reading the description, we matched the ones that seemed to go together first, then what was left we could tell by what we already knew. Sir! The teeth grind the food; stomach acids break down the food.
How did your group determine Yes Sir! which function went with each organ? Sir! When cracker enters the mouth, the teeth grind and break up the cracker. Now, how might the digestive system change food into a form that can be used by the body? I told you yesterday to bring 1 pack of Sky flakes, each group. Isn’t?
What happened when you put the cracker inside your mouth? Very Good!
Sir! Saliva makes the food wet and makes it easier to swallow so you don’t choke.
The more one chews the more the cracker is broken up into smaller pieces. Breaking up the cracker into smaller pieces is a physical change because itis still When something reacts with a cracker. But there is saliva in something, it changes, so if the iodine reacts with a starch, something the mouth. happens like maybe a color change, a How can saliva be helpful in temperature change, a gas formed; something like that. digestion? Crackers are a starch. Potatoes and rice are also starches. Iodine is used as an indicator for starch, meaning iodine “reacts” when it comes into contact with starches. What does “reacts” mean?
Explore 1: The Mouth Materials: 2 Crackers/Sky flakes 5 drops ofSaliva, 1 sheet of bond paper 2 Droppers
Cracker 1 Cracker 2
(The three groups execute the given procedures. Record observations of both crackers.)
Ask students to place the 2 crackers about 3 inches apart on a paper towel and to label on the paper towel below the crackers: #1 & #2. Explain that amylaseCracker1 is Cracker One representative With a chemical that is found in human 2 each group saliva w/o saliva where it begins the presents the result Saliva chemical process of digestion. of their After 3 experiment. Provide amylaseminutes solution and After have students use a dropper to The color of the adding cracker without place 5 drops of amylase iodine amylase when solution/ saliva on cracker #1. solution added the iodine is Place 2 drops of iodine solution dark purple. The cracker with amylase on each cracker. Observe the did not turn dark blue/purple when change that occurs; record added with iodine. observations on chart. Record your observation using Sir! It gets rid of the starch; it the chart. Cracker1 Cracker changes the 2starch into something With else. w/o Saliva After recording their saliva observations, let one After 3 representative each minutes group share the After adding iodine solution
results of their experiment.
Sir! Peristalsis.
Very Good! What inference can we make about amylase? Exactly! Saliva contains compounds that are important in breaking down food. The esophagus is a long muscular tube that leads to the stomach. Food doesn’t travel by gravity; rather it is pushed by a wavelike contraction of muscles known as _______________________. Very Good! The esophagus makes quick work of this job. It can squeeze food to the stomach in 7 seconds. Explore 2: The Esophagus The next activity will simulate how the esophagus works. Materials: Balloon 1 teaspoon cooking oil ¼ piece of bread 1) Cut the end of the balloon so that it makes a long, flexible tube. 2) Pour 1 teaspoon (5 ml) of cooking oil into the balloon. 3) Take the ¼ piece of bread and make it into a ball about the size of a marble. 4) Stick the bread into one end of the balloon. 5) Squeeze the balloon behind the ball of bread with one hand. Keeping that hand in place, cross your other hand over the first hand, continue squeezing to move the bread down the balloon. This activity simulates “peristalsis” the rhythmic, wavelike contractions of the muscles that line the digestive
(Students procedure.)
execute
the
given
tract. Explore #3: The Stomach Distribute materials to each pair of students: 4 unfrosted animal crackers, zip-lock bag, and ¼ cup of water. Tell students to place broken cookies and water into the zip-lock bag and squeeze the bag many times.
E. Application • Lab sheet (1 per student) • 2 Ziploc style sandwich bags (per student) • Water • Assortment of foods (i.e., bread, chips, grapes) • Beaker or clear container (1 per group) • Vinegar (approximately 50 mL) • Chalk (1 Piece per group) • Tootsie Roll (1 per student) • Clock Procedure: 1. Obtain 2 plastic sandwich bags from the teacher. Carefully fill each sandwich bag halfway full with water. 2. Add food items to both of your bags. Be sure you: a) do not overfill the bags b) add approximately the same amount and type of food to each bag c) carefully remove air and zip the bags closed ensuring that they don’t leak d) do not squeeze the bags in any way 3. Designate one bag to represent “No Muscular Action”(stomach 1) and the other bag to represent “With Muscular Action” (stomach 2). 4. Taking note of the time, observe the contents of stomach 1. Record your initial observations
under “No Muscular Action” in Data Table 1. Place the bag off to the side and check/record observations again in 5 minutes. Try not to move the bag too much as you make your observations. You will be conducting 3 trials. 5. Take stomach 2 and gently squeeze the bag 6 times being sure not to rip or accidently open it. Record your initial observation under “With Muscular Action” in Data Table 1. Place the bag off to the side. Each time you check the bag squeeze it 6more times, then record your observations. Record your observations every 5 minutes. You willbe conducting 3 trials. 6. While you are waiting, one person from your group will obtain a container filled with 50 mL of vinegar and a piece of chalk from your teacher. Position the container in an area where your entire lab group can view it. Place the small piece of chalk into the vinegar and observe what takes place. In Figure 2draw, label, and explain what you observe. 7. Next, obtain from your teacher a single tootsie roll. Unwrap the tootsie roll and place it in your mouth. Keeping your mouth closed, you may suck but NOT chew the tootsie roll. Without ever chewing you are going to record in Data Table 3the time it takes for the tootsie roll to completely dissolve in your mouth from start to finish. When finished, record both your stopping and total times. 8. Once you complete all 3 trials, take your “stomachs” to the designated drop off areas in the classroom.
F. Generalization
IV. Evaluation
V. Assignment
Number of students within the mastery level:_____________ Number of students need remediation:_____________________ Activity/ies undertaken:______________________________________ Prepared by:
LESTER E. ORPILLA Student Teacher Checked by: MRS. JANETTE U. ABAN Cooperating Teacher, Science 8
