HUMAN ACTIVITIES AND THE CYCLES IN AN ECOSYSTEM

1. DETAILED LESSON PLAN IN SCIENCE VI
I. OBJECTIVES
At the end of the lesson, the pupils are expected to:
a. Identify the effects of human activities and the cycles in an ecosystem.
b. Illustrate the cycle in an ecosystem
c. Give importance to the ecosystem
II. LEARNING CONTENT
TOPIC: Human Activities and the Cycles in an Ecosystem
MATERIALS: Charts, Pictures
REFERENCE: Science and Health 6, pp.84-87
III. LEARNING EXPERIENCE
TEACHER’S ACTIVITY PUPIL’S ACTIVITY
A. PREPARATION
 Opening Prayer
 Checking of Attendance
 Review of the Past Lesson
B. PRESENTATION
The atmosphere normally has about
21% oygen and 0.03% carbon dioxide.
The continuous exchange of these gases
between green plants and animals maintains
the oxygen-carbon dioxide level.
Unfortunately, man’s destructive activities
disrupt this balance.
Class, why do you think that man’s
destructive activities disrupt this balance?
(The teacher will call one pupil)
(The pupil will
answer)
Very Good! So class, if trees and another
green plant become scarce in an ecosystem

2. , the supply of oxygen is reduced.
As a result, the amount of CO2 in the air
increases, and the O2 and CO2 is disrupted.
Class, what do you think will happen to animals
And human if the amount of air is reduced?
(Pupils will answer)
Possible Answer:
Many animals and
humans will die.
Very good! Many animals and humans
may die due to the shortage of the amount of
oxygen in the air.
(Show some pictures about Oxygen-Carbon
Cycle)
In the Oxygen-Carbon Cycle, green plants
Use the carbon dioxide in the air and it also
dissolve in the oceans and seas.
Marine plants take in carbon dioxide to
manufacture food. These plants are the energy
source of marine animals. The continuity
of the cycle depends on the materials
and energy available in the system.
Class, what do you think is the cause of
disruption?
Ma’am. Because of
the natural disaster
and human activities.
Very good. Can you give me examples of
natural calamities?
(Call 3 pupils)
- Typhoon
- Eartquakes
- Volcanic
Eruptions
(Show pictures of the natural disasters.)
Typhoon, earthquakes, and volcanic
eruptions can destroy an ecosystem.
What about human activities that disrupt
The cycles in ecosystem?
(Call some pupils)

3. - Throwing of
garbage in the
river
- Cutting of trees
- Kaingin
- Spraying of
insecticides
- Combustion of
fossils
Very good!
(Post the picture of “Throwing of Garbage”)
Throwing garbage can destroy the ecosystem.
The river’s natural capacity to break the
material slows down. As a result, the once clear
pond becomes dirty due to the amount of
materials dumped in it.
(Show pictures of “Cutting Of Trees”)
The cutting down of trees has resulted in the rapid
denudation of our forest. Without trees there
is nothing to absorb excess amount of Carbon Dioxide
in the atmosphere which results to the abnormal
warming of the earth.
The next human activity is “Pagkakaingin”.
Why do you think pagkakaingin destroys the
ecosystem?
(The teacher will call pupils)
Possible answer: The
birds and other living
organisms will be
deprived of natural
habitat.
Yes. Kaingin brings harmful effects to our ecosystem.
Kaingin is a way of clearing a forest area and convert
it into an agricultural lands, or housing projects to
accommodate the growing population.
Therefore, the birds and other wild animals will be
deprived of natural habitat.

4. Another example is the use of insecticides.
(Post the picture)
Class, why do you think the use of insecticides
Also destroys the ecosystem?
Possible answer: It pollutes
the land
Right. The use of chemical fertilizers, pesticides,
and pollutes the soil. Also, these chemicals harm
plants and is also possible to harm humans and
animals once taken.
C. GENERALIZATION
The cycles of ecosystem may be disrupted by natural disasters such as typhoon,
earthquakes, volcanic eruptions and by human activities such as uncontrooled
cutting of trss, kaingin, combustion of fossil fuels, and throwing of garbage in the
river.
IV. EVALUATION
TRUE OR FALSE.
1. Typhoon is a natural disaster. (True)
2. Throwing garbage can destroy the ecosystem. (True)
3. Kaingin is a way of clearing a forest area and convert it into an agricultural
lands, or housing projects to accommodate the growing population. (True)
4. The birds and other living organisms will be deprived of natural habitat is not
a harmful effect of pagkakaingin. (False)
5. Without trees there is nothing to absorb excess amount of Carbon Dioxide in
the atmosphere which results to the abnormal warming of the earth. (True)
V. ASSIGNMENT
List down fast growing trees that should be planted to increase forest cover.