SUBJECT: SCIENCE FORM: 5

CHAPTER 3: PRESERVATION AND CONSERVATION OF THE ENVIRONMENT

3.1 Balance in Nature

What is the meaning of balance in nature?

Refer to the situation where living things and non living things ____________________________ for their __________________________ way. That means they are _____________ on one another so that their ______________________ continue to exist in natural state.

Natural Cycle Helps to Maintain Balance in Nature:

1) Water Cycle

2) Carbon Cycle

Absorption

Absorption

3) Nitrogen Cycle

Food Webs Helps to Maintain Balance in Nature:

a) Food chains

Food relationship among organisms forms food chains. That means green plants make their own food by _____________________, and some animals get their food from eating this green plant, and some other animals get their food by eating _________________ (animals that feed only green plants)

Examples of food chains are given below:

Energy is ________________ from organism to organism in food chain. Some of energy is _____________ during transfer. It is because of :

1) waste (_______________) product by organism 2) _____________ lost to surrounding3)

No energy is ____________________________ in food chains.

Original source of energy in food chains is the ____________. Why? Because the sun __________ _____________________________ so that they can make their own food by photosynthesis

Plant proteins

Nitrates

Animal proteins

Absorption

Nutrition

Absorption

\

b) Food webs

Food chains don’t exist _______________ on their own in nature. In fact, they are _______________. This inter-relationship among food chains forms ___________________

Example of food web is given below:

Producers : All producers are _____________________, because they make their own food under sunlight via photosynthesis

Primary consumer : Animals which eats plants, either _________________________

Secondary consumer: Animals which eats _________________ consumers

Tertiary consumer : Animals which eats _____________________ consumers

Decomposer : They are ___________________________ and other organisms which break up dead plants and animals into __________________. These minerals will be ____________ again by plants.

Stable food web ____________________________ in nature. The balance of ecosystem will be ___________________ if members are taken ____________ or ______________ members are put in.

c) Pyramid of Numbers

It shows the relative number of organisms in a particular food chain

Producers Primary consumers

Secondary consumers

Tertiary consumers

Decomposer

Diagram 3.1

Size of consumer increase

Number of organism decrease

As we move up from the _______________________ of the pyramid,a) the number of organisms __________________b) the organisms become ___________________ and maybe ________________c) the energy transferred _______________ (Only __________ energy transferred from one organism to another)

The relative number of organisms at each stage of the number of pyramid is ________________. Otherwise, __________________ will be disrupted.

Effects of Natural Disasters on the Balance in Nature:

a) Forest fires

i. It can destroys large ______________ and large variety of plants and animalsii. After a forest fire, the balance of nature in that area is _______________. iii. The plants grow again, but __________ before animals will returniv. Forest fire produces plenty of ________________. v. These substance form _________________, and result in ______________ and healthy

problem for human beings such as ______________________________

b) Drought

i. Refer to long period of ___________________________.ii. Plants and animals don’t get ____________ water supplies. iii. Plants are the first to ____________________, followed by the animals.iv. In severe drought, the complete habitat can be turned into a _________-like region. v. It is followed by a ____________. vi. People who live in that drought area will be _________________ to death unless they receive

aid from outside the affected region

c) Flood

i. It is caused by heavy _____________ such as ______________ii. Large variety of plants is destroyed, and many animals are _________. iii. Those survived animals have to find ________________ to find food.iv. Floods are likely to wash away the _____________ and all its ________. v. The surviving plants will ___________ of nutrients.vi. Floods also cause the ____________________, and as a result, a lot of _______________

diseases such as _________________ and _________________ are emerged.

d) Typhoons

i. It is great __________________ which bring ______________________ and winds of very ________________

ii. It can sweep across a whole region very ___________, inflicting wide spread and catastrophic _________________________ to property and causing ____________ of lives (animals, plants and human beings).

iii. It also causes _________________

e) Earthquake

i. It happens because of movement of _________________ below the Earth’s crustii. Normally lasts at most for _________________iii. Can cause catastrophic destruction, loss of lives and upset the _________________iv. Example: _________________ Earthquake on 1994v. However, scientists can predict where the big earthquake will occurs fairly and ___________,

and so that people who live in earthquake-prone area will take proper _________________.vi. If an earthquake takes place on sea floor, _____________ (mighty sea wave as tall as coconut

tree and moving at _________________ km per hour) may be produced.vii. Example: Tsunami on _________________

f) Volcanic eruption

i. It throws out __________________________________ such as _________________ (CO), _________________ (SO2) and _________________ (HS)

ii. The dust and __________ gases pollute the air and dissolve in the rain to form ______iii. The molten materials, called _________, can flow and spread out over large areas. iv. It will destroy ______________ and kills organisms which are in its way.v. Example: _________________ volcanic eruption in 1883

Ways for Maintaining the Balance in Nature:

1) Prevent _________________ pollution2) Prevent _________________3) Keep our ponds, _________________ clean4) Maintain the _________________ of the soil5) Prevent the _________________ of the topsoil6) _________________ after logging7) Do not destroy plants and animals _________________.8) Set up the _________________ if there will be high possibility for natural disaster to occur

3.2 Environmental Pollution and Its Effects

Source of Environmental Pollution:

1) Uncontrolled use of _________________ (e.g: diesel and coal)i. As a result, they produce a lot of carbon dioxide (CO2), carbon monoxide (CO),

_______________________________________________. All of them are acidic gases.ii. These gases dissolve in rain, to form acid rain, which is very _________________.

2) Uncontrolled use of _________________________________ _ in agriculture

i. Some of pesticides and fungicides sprayed onto the crops escape into the air _________________ and pollute it

ii. Excess pesticides, fungicides and fertilizers which dissolve in water below the ground finally flow into the _________________ nearby like pond, lake or river.

iii. As result, the water will be _________________.

3) Emission of toxic _________________ ____________from motor vehicles

i. Toxic gases such carbon monoxide (CO) and sulphur dioxide (SO2), and smoke comes from motor vehicles will pollute the air in big cities.

ii. Besides, the continuous noise comes from motor vehicles in the big cities can be very _________________.

4) Improper disposal of industrial waste

i. Industrial wastes such as __________________________________ __________________ are indiscriminately disposed into the environment.

ii. Even the _________________ are not being disposed in a safe and proper way.

5) Improper disposal of rubbish

i. Some of plastics are _________________. ii. That means, it _________________ _______________by bacteria. iii. As a result, they stays in the environment for hundred of years.iv. _________________ ___________________________which are not properly managed can

pollute the water and land.

6) Extensive use of CFC (chlorofluorocarbon )

i. CFC is the main pollutant which destroys the _________________ in the atmosphere. ii. It is extensively used as a _________________ in _________________ and _____________.

Effects of Environmental Pollution:

7) Harmful Effect on Human Health

Pollutant Harmful EffectsLead (Pb) Cause

Mercury (Hg) Destroys the Cause _________________ in fetusLeading to _________________ diseases

Chromium (Cr) Cause adverse effects if it accumulate too much in

Carbon monoxide (CO) Depriving _________________ from our body Sulphur dioxide (SO2) Irritate and corrode human’s _________________ system

Cause Nitrogen dioxide (NO2) Same as above

Smoke Cause Sewage Cause water borne disease such as

Radioactive waste Cause Cause _________________ in fetusCause _________________, even worse death

Noise Lead to the total _______________ and _______ disorders

8) Destruction of Habitats

Pollutant Harmful EffectsAcid rain Corrodes the mineral in the soil, making the soil is unsuitable

___________ for plants.Cause the roots of plants to be __________ to absorb water.

Oil spills Pollute the natural _____________________ like sea, river and lakeWhen oil spills is washed to the shore, it makes the coast line as __________________ place for marine organisms

Clearing of forests for _________________ and etc deprive plants, animals and indigenous people from their habitat.

9) Extinction of Species

This issue comes from many causes, like:

1. Destruction of their habitats by :-

2. Pollution of natural water resources by :-

3. __________________ hunting

10) Loss of Economic Resources

This matter comes from many reasons, like:

1. Destruction of forests by :- a) b) natural disasters (e.g:

2. Pollution of soil by :- a) _________________ of industrial waste b) extensive use of _________________

3. _________________ settling (comes from thick haze) on the leaves of the green plants prevent them to receive _________________ for photosynthesis process.

3. Pollution of natural water resources by :-

Global Warming:

Refer to phenomena where the Earth’s temperature ____________ due to several factors such as:1) Clearing of large area of _________________2) Burning of fossil fuels in _________________

i. Since quantity of CO2 _________________ in atmosphere and it _________________ than air,

ii. it will forms a layer in _________________ surrounding the Earthiii. Heat from the ___________ can pass through the layer of CO2 to the Earth. iv. But heat and infrared _________________ from the Earth ____________ pass through the

layer of CO2 into outer space.

v. Heat and _______________ trapped between the layer of CO2 and the Earth makes the Earth’s temperature ______________.

vi. Global warming is similar to the ________________. vii. Besides CO2 gas, there are other gases that can cause global warming like _______________

Thinning of Ozone Layers:

i. Refer to phenomena where the ozone’s layer becomes ________ due to usage of CFC in refrigerator, air conditioner and _________________

ii. Basically, ozone is made up with the combination of __________ oxygen atoms (O3). iii. It formed and _________________ at the same rate so that there is no change in the

_____________ of ozone’s layer. iv. The usage of ozone is to ___________ the Earth from excess of __________ (UV) light

from the Sunv. However, the usage of CFC increases the rate of ozone’s _________if it is not treated

immediately, vi. High intensity UV light can cause : _________________ kill the _________________ of cells damage _________________ tissue reduce _________________ to fight disease increase the _________________ of the Earth

3.3 Conservation of the Environment

How to control environmental pollution?

1. Controls the usage of fossils fuel

2. “ disposal of industrial waste

3. “ usage of chemical pesticides and fertillizers

4. “ emission of pollutants from motor vehicles

5. “ disposal of rubbish

6. “ usage of CFC

1. Use __________________________2. Use alternative sources (___________________________)

1. Build very high _________ and use _____________________ inside it 2. Radioactive waste should be stored in ___________________ __ container before it is disposed on the ____________________________.

1. ____________ materials2. Recycle ______________________3. Set up __________________________ along a river

1. Practice ____________________2. Practice _________________3. Use organic fertilizer such as _________________

1. ____________ the usage of CFC2. Replace CFC with ___________

1. Use _______________________2. Use ____________________3. Install a ___________ at exhaust system4. Use _____________________________