شرح منهج العلوم كامل 2009 بالانجليزي

[ولاء حمدان]

Plant makes its own food

- How does the plant obtain its food?
Plants do not eat food the way animal do.
The plant makes its own food through photosynthesis process.

Photosynthesis process:
Is a vital process that takes place in the plant "espacially the leaves" in the presence of:
- Light energy "sunlight"
- Water
- Carbon dioxide gas
- Chlorophyll.

Chlorophyll:
- Is a pigment which makes plants look green and absorb light energy.
Sunlight is essential for photosynthesis:





Chlorophyll is necessary for photosynthesis process:


- The variegated leaf:
It contains parts with chlorophyll "green" and other parts have no chlorophyll "white".

- Carbon dioxide is essential for photosynthesis:

oxygen is produced during photosynthesis:


- The importance of photosynthesis process:
- During photosynthesis plants make the food which animals and human beings need.
- Plants renew the air by replacing the oxygen used in vital processes.
- Plants remove the carbon dioxide form the air through photosynthesis.

- the green plants are producing organisms "producers" for their food.
- Plant leaves are food factories.
- Carbon dioxide enters the plant through stomata
Somata:
- They are small opening on both sides of the leaf.
- The number of stomata of the lower surface of the leaf is more than those of the upper surface of the same plant leaf.



- Molecules of sugar "glucose" are joined together to form starch.
- Starch itself can change to fats or proteins in plant cells in the presence of some materials made by the plant and some salts.

[ولاء حمدان]

The necessary groups of food for human body








The balanced diet:
- Is the diet that provides the body with the necessary quantities of suitable foods and it contains proteins, sugars, starch, fats, mineral salts and vitamins.

The balanced diet conditions:
- It contains the main food groups.
- It suits age, temperature and kind of work.
- It is fit to eat "its colour, smell does not change ie. its expiry period has not been ended.

[ولاء حمدان]

Cleanlines of food and utensisl used for preparing and handing

The sources of food pollution:
- Dirty utensils and hands used during preparation of food and handling.
- Dust particles and microbes, which are suspended in the atmospheric air.
- Flies and cockroaches.
- Soil residues and fertilizers.

Diseases caused by dirty foods:
1- Food poisoning
* Its symptoms:
- Vomiting and / or diarrhea.
- Fever "temperature rising"
- abdominal pains "cramps"

2- Gastroentritis

3- Parasites and worms such as "Ascaris"

Ascaris "Intestine worm":
- This is a kind of worms , which lives in the small intestin, feeds and shares with the infected person his digested food.
- A result, the infected person suffers from food deficiency diseases, such as anemia and feels lazy and tired after even a little work.



- How can you keep your food clean?
1- Wash fruits and vegetables carefully with tap water before eating.
2- Cover the foods to prevent dust, cockroaches and flies away from foods.
3- Wash all utensils used in preparing and handling food with soap and water.
4- Wash hands and utensils used in eating with soap and water.

[ولاء حمدان]

Energy and its forms

Energy:
It is the ability to do work or to make a change.
Energy forms are:
1- Light energy
2- Chemical energy
3- Kinetic energy
4- Potential energy.
5- Thermal (heat) energy
6- Sound energy
7- Electric energy
8- Magnetic energy.

1- Light energy:
It is a property of light enables it to do work.
2- Chemical energy:
It is the energy produced due to chemical reactions.
3- Kinetic energy:
It is the energy gained by a body due to its motion
Examples of kinetic energy:
a- A moving car.
b- A bullet fired from a gun.
c- Running water.
4- Potential energy:
It is the energy gained by a body due to its position.
Example of potential energy
Water in a water fall

5- Thermal (heat) energy:





6- Sound energy:
It is the energy produced due to the vibration of objects.



7- Electric energy:
It is a form of energy because it causes the movement of objects which need electricity to move.

8- Magnetic energy:
Magnetism:
It is an invisible force that can make some things move towards or away from each other.

[ولاء حمدان]

1- Kinetic energy changes to potential energy then potential energy changes to kinetic energy: