Lesson Notes By Weeks and Term - Junior Secondary School 3

SUBJECT:�BASIC SCIENCE���

CLASS:� JSS3

DATE:

TERM: 3RD TERM

WEEK 3

TOPIC:��� OUR DISAPPEARING FOREST

Human activities such as road construction, house building, siting of industries, burning of forests for farming and hunting, and burning of wood as fuel for cooking purposes reduce the number of large trees we have and so destroy the forests. And so our forest is disappearing.�

Deforestation: is the cutting down of trees in our forest.

Afforestation: is the planting of trees where they have not existed before.

Reforestation: is the replanting of threes where they were originally before.

THE EFFECTS OF DEFORESTATION

1. Gradual disappearance of wild life in our environment.
2. Our soil is exposed to flood erosion.

iii.��� Gradual disappearance of forest and the consequent high cost of fire wood, tuber, paper and other by products of wood.

EVALUATION

1. What is Deforestation?
2. What are the effects of deforestation?

SUBTOPIC:� CAUSES OF THE DISAPPEARANCE OF FORESTS.

1. Mature forests are almost non-existent in West Africa, today due to human activities.
2. Poor farming methods like shifting cultivation have led to deforestation.
3. Overgrazing by animal
4. Use of timber in building houses, furniture and bridges.
5. Most people in rural areas use firewood abundantly for cooking

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2. Desert encroachment such as the Sahara Desert is due to climate factors.

EVALUATION

1. Mention three causes of the disappearance of forest due to human activities.

SUBTOPIC: WAYS OF PRESERVING OUR FORESTS.

1. Reforestation i.e. our forest should be replanted.
2. Nomadic way of life in Nigeria should be avoided in order to prevent grazing.
3. Modern method of farming should be adopted and poor method of farming should be abolished.
4. Checking of desert encroachment by irrigation of the area and afforestation.
5. Other fuels such as kerosene, gas etc should mainly be used for cooking in order to minimize the quantity of firewood used annually.

EVALUATION

1. Mention ways of preserving our forests.

SUBTOPIC:� NITROGEN CYCLE

Nitrogen is an essential constituent of proteins, a group of substances found in all living cells. About 79% of air is made up of gaseous nitrogen. In nature, nitrogen is constantly being removed from the soil and returned to it via the nitrogen cycle. Nitrogen moves in cycle in the community just as water does.

WEEKEND ASSIGNMENT

1. The importance of our forest are the following except that forest

��� (a) Provides wood for building and furniture

��� (b) Provides pulp and paper

(c) It harbours animals that we eat and use their skins for making bags, drums, and dresses.���

(d) All of the above are the uses forest

2. Paper is obtained from ____ (a) wood crops (b) textile crops (c) flower (d) leaves
3. What percentage is the gas that supports burning in the air? � (a) 79% (b) 0.03% (c) 80% (d) 0.003%
4. Modern tools are better than the traditional tools for the following reasons except

��� (a) They are smaller and handy (b) Much human energy is needed

��� (c) Little human energy is needed.

��� (d) No human energy is needed.

THEORY

1. What is � (a) Reforestation/ � (b) Afforestation?
2. Draw Nitrogen cycle

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