Homeostasis

Subject        : Science Form 1 

Topic           : Chapter 3; Homeostasis  

Sub-topic    : Homeostasis in human  

Teaching & Learning Strategies : Contextual Learning, outdoor activities  

Students' Activities                      : Simple physical activities, group discussion

Introduction 

Homeostasis is a new topic in KSSM Science Form 1. Previously in KBSM, homeostasis is only taught to form 5 students. So, when I first heard about this topic, even I was nervous. Don’t even remember whether I ever learnt it before this in Biology or not. Totally forgot and no idea. Haha…

For me, the concept of homeostasis is too abstract, especially the explanations. When I first taught the students, they were all blurr. They can understand the basics, but when they need to explain, their mind ‘blank’.  

Therefore, I use another learning session to repeat this topic by using different learning strategies. Instead of just sitting in the classroom, see the video / power point, this time I asked them to experience the homeostasis themselves. All the learning activities were done outside the classroom (at the volleyball court) 

Induction Set 

I asked students whether they ever took their pulse rate or whether they know the normal rate of pulse. Two third of the students answered NO.

Then, I asked the students to measure their pulse rate in one minute.

After that, asked some students to share their pulse rate. Some of them got very low (around 40-50) and some of them got more than 100.

I asked students to give some idea why do they think the value is different from one another and some of them have bigger difference.

Warm-up

Students were asked to jog around the volleyball court for 3 laps.  

After that, they were asked to measure their pulse rate again and compare the value with the previous. (of course the value increases)

Keep asking them why:

Why the pulse rate increases after physical activity?

Why are we breathing faster than before?

Why do we feel tired?

What other changes do you feel / observe? (refer to sweating)

Why are we sweating?

Why do we feel thirsty?

What happen if we drink too much?

Let the students think by themselves and discuss with their friends.

After 15 minutes rest, they measure their pulse rate for the third time.

Now, the value decreases. Why?

Explanations

Start with the definition of homeostasis

Homeostasis is the maintenance of the body system to keep our body in a balance condition, for example the body temperature and water content.

When we feel hot, we are sweating to cool down our body. Heat from body is released together with the sweat.
When we are sweating, the water content inside our body decreases. Therefore, we feel thirsty because the body need us to replace the water lost by drinking more water. 

When we feel cold, we are shivering. More heat energy produced to keep our body warm.

When we drink more water, more urine will be produced to maintain water content inside the body. Oppositely, when we drink less water, less urine produced.

During physical activity, more oxygen needed. Heart will pump more blood and breathing mechanism increases. That’s why pulse rate increases as well as the breathing rate.

Group Discussion  

Students will be bored if everything is explained by the teacher.

So, let them explore more by themselves.

Students are asked to discuss in group what are the systems involved in homeostasis.

After the discussion, students present and explain the concept of homeostasis.

Students are then asked to observe their surroundings.  

Observe what animals usually do (we have cats and dogs at our school)

Closure 

Homeostasis plays an important role in our daily life. The body temperature and water content in our body must be maintained in an optimum level to keep our body in a balance condition. Can you predict what will happen if our kidneys cannot function properly? Will it affect homeostasis?

LIMITATIONS

For form 1 syllabus, homeostasis is only focus on regulation of water content and body temperature. The conditions discussed are including sweating, shivering, heartbeat rate and production of urine. The two systems involve are endocrine system and urinary system.