Sample of a Detailed Lesson Plan in Biology

I.                   Objectives

                  At the end of this learning session, the students should be able to:

A.    define homeostasis and identify its function and control mechanisms;

B.     appreciate how body adjusts to maintain balance in the relatively stable inner conditions;

C.     construct a diagram presenting how homeostasis works and;

D.    develop a way to keep the body in homeostasis

II.                Subject Matter    

A.    Topic: Homeostasis

B.     Instructional Materials           

     Pictures

      OHP

      Acetate

      Chalkboard

C.     References

      Marieb, Elaine N. Essentials of Human Anatomy and Physiology. Pearson              Education South Asia PTE. Ltd. 2004. pp 9-11

      CD ROM: Encarta Encyclopedia 2006 

III.             Procedures

A.    Preliminary Activity

1.      Opening Prayer

2.      Checking of Attendance

3.      Mood Setting

Teacher’s Activity

Student’s Activity

(This shall take 3 minutes) A pleasant morning to all of you, today we shall discuss a new topic under Chapter 1. But before we start, I want to show you these pictures. What can you observe in these sketches? (The teacher shall post the pictures in the board and label it with A and B) Yes, you are raising your hand, Mr./Ms.______________________ That’s a good observation. Thank You Mr./Ms.__________________ Now, all of us shiver when we feel cold and sweat when we feel hot, but why is that so? Anyone? Okay Mr./.Ms. ______________ Good. So, you made mention of the word balance and this word entails the concept that we are going to discuss. That is homeostasis.

Good Morning, Ma’am! (students shall raise their hands) Ma’am, the picture A shows that the little girl is shivering while in picture B the boy is sweating. (students shall raise their hands) Ma’am for me, I think that we do these sorts of activities in order for our system to be balanced.

B.     Developmental Activity

Teacher’s Activity

Student’s Activity

(This shall take 30 minutes of the learning session) Homeostasis comes from the root word homeo meaning same and stasis which means standing still. Since I have asked you last Friday to do some readings about Homeostasis, as an assignment, can anyone of you share their definition of this word? Yes? Mr./Ms. ______________ Good. Homeostasis is the body’s ability to maintain relatively stable internal conditions despite the continuous change of condition in the environment. But does this mean that because of homeostasis our internal conditions are always accurately the same? Like in our body temperature, should it remain 37 degree Centigrade? Can’t it be 36.8 or 37. 3? Yes? Mr./Ms. ______________ Yes. This means that we have a set point where the inner conditions move along its homeostatic range; not only fixed in its point. Since we are all aware that homeostasis is the ability of the body to be kept in an equilibrium state, do you think, what specific inner conditions should be maintained in normal state? Yes? Mr./Ms. ______________ Thank You. Now, we see that there are many factors which our body should normalize. These are all vital in order for us to remain living. In relation to that we should be familiar to the process on how homeostasis work in our body to regulate and to maintain the body in a balance state. Okay, so turn your chairs around facing the wall so you may be familiar about the concepts and process involved within its different control mechanisms. Let us first start with the concepts. We should keep in mind is that the   nervous system and the endocrine glands are responsible for this. These two communicate through electrical signal via different pathways. Therefore, these two are called information carrier. The variable is also regarded as the factor being regulated. Now, there are three components in the homeostatic control mechanisms. The first one is the receptor; The second is the control center and;  the third is the Effector. Who wants to read their definition? Yes. Mr./ Ms______________?   Thank You, and the next, okay. Mr./ Ms______________? And the last, yes. Mr. / Ms______________? Okay, so to be more familiar with these concepts, let us proceed to the process. It would all start when there is a change. That change is called stimulus. This is found on the environment. When that stimulus is received by the sensory receptors, It would then transmit the information to the control center. This information is sent through the afferent pathway. This is known as the input. Now, when it reaches the control center, this will try to determine if that stimulus is likely to affect the set point or the normal state. After that, it will make a plan, and that plan entails the response to be performed. The control center will transmit the information called output to the effector along the efferent pathway. Now, let us suppose that it reaches already the effector component. This then will perform the necessary action a instructed by the control center. Now, if the effector is able to successfully do the action, the body will return to its homeostatic state. Ok so for example, the stimulus is the environment is very hot. Let’s just imagine that it is already summer. How would it be processed by the homeostatic components? Yes. Mr. / Ms. _______________?  Very good. So think that you already understand the process within the homeostatic control mechanisms. So lets jump on to the types on control mechanisms. Actually there are two. Who wants to give me the first? Yes. Mr./ Ms. __________________. Okay and the second? Yes. Mr./ Ms. ___________________. Thank you, so how do these two differ? Who has any idea? Yes Mr. / Ms. ___________________. Okay, well said. So the negative feedback mechanism is the one which activates when there is excessive heart rate, blood pressure, breathing rate and blood levels of glucose oxygen, carbon dioxide and minerals. You may write this down. Like, when you ran, the intensity of the breathing rate is high, isn’t it that it slows down until your breathing is normal? So that’s how negative feedback mechanism or NFM works. But, let me clear this class, NFM is always normal. Although it was called negative, it does not mean that it harms the body. Additionally, this is more common in our body. The positive feedback mechanism, however, is very rare. This then handles the infrequent events like blood clotting and birth of a baby.   But what causes the imbalance in our body? Any idea? Yes. Mr. / Ms. ________________. Okay.  So as we age, we encounter different stimulus in the environment. Some may be accumulated through time, some are not. Like the second hand smokers, they acquire nicotine in their lungs and that is accumulated. The toxic does not easily goes out of the body. The food also, when we digested it, there are fecal materials which should be released, otherwise it would be poisoning the body. Homeostasis is also in charge of those tasks. Okay. So, are there any questions? Perhaps, the lesson becomes easy because you all did your assignments, very well. Now to generalize the whole discussion, here is the movie clip that would synthesize the learning we have today. Kindly turn off the light please. (Movie clip run time 2 minutes)

(students raised their hands) Homeostasis deals with the function of the body to maintain the balance in the system within the body itself. (students raised their hands) No, because homeostasis lets the body’s internal condition to change and vary but it would always remain in a dynamic state of equilibrium. (students raised their hands) Blood levels of vital nutrients Heart activity Blood pressure Body temperature (students raised their hands) Receptor- it composes of sensors thart monitor and responds to changes in the environment. This is responsible for sending information gained from the stimulus to the control center. Control Center- it determines the level or the set point at which a variable is to be maintained. It is in our brain which analyzes the information sent by the receptors and determines an appropriate response. Effector- this provides the means for the control center’s response to stimulus. (students raised their hands) When the receptor, sensed that it is hot, it will send a message to the brain. The brain then will instruct the muscles what to do. It is possible that the person will sweat so as to keep his body temperature in balance. (students raised their hands) Positive Feedback Mechanisms Negative Feedback Mechanisms (students raised their hands) The positive feedback tolerates while the negative stops. (students raised their hands) Because the environment is changing, like the temperature. None.

C.     Application

Teacher’s Activity

Student’s Activity

So for your activity, I want you to get a one whole sheet of pad paper. I would like you to write a paragraph about this title, “Homeostasis— because of you, my body is Healthy.” It’s just like a letter, say everything about what you feel on having this, and just think as though that homeostasis is a person taking care of you. Also include your thoughts on how would you take care of this body function.   In the back of your letter, make your own diagram on how homeostasis work with an example. It should be complete. You may start now. This shall be for 20 minutes. Are you all done? Okay, kindly pass all your papers in front.

(Students get their papers and starts answering) (Students pass their papers)

D.    Evaluation

Teacher’s Activity

Student’s Activity

(This shall take 5 minutes) So for your quiz, get a 1/4 sheet of pad paper and number it from 1 to 15. Ready? Okay. These are the questions. I’ll only repeat it twice, so please listen carefully. 1. It is the one who receives the information from the environment. 2. What is the factor being regulated by homeostatic mechanisms? 3. What do you call the process of control center where in the information is sent to the effector? 4.-7 Give examples of variables which are being regulated. 8-9. What are the two feedback mechanisms and differentiate each. Key points will do. 10-12. What are the three components of homeostatic control mechanism? 13-14. What are the two information carriers?  15. Give the definition of homeostasis. All done? Pencils up. Now pass your papers. I’ll give you the result tomorrow.

(Students get papers) Answers: Receptors variables output blood pressure heart activity body temperature wastes positive feedback mechanism – infrequent events negative feedback mechanism-      requires continuous adjustment to       reduce the intensity or shut down the      effect of the stimulus receptors control center/brain effector/muscles blood hormone It is the body’s ability to maintain relatively stable internal conditions.

IV.             Assignment

Teacher’s Activity	Student’s Activity
So for your assignment, read about the cells.  That’s it for now. Hope you learn something today. God bless.	(Students take notes) Goodbye and Thank you, Ma’am.