ملخص دروس العلوم باللغة الانجليزية

The human body :
-The human body is made up of a number of "systems".
-Each system performs "a certain function".

For example :


- Digestive system: Digests and absorbs food.
- Respiratory system: Carries out the process of breathing.
- Circulatory system: Distributes the digested food and oxygen all over the body.
- Urinary system: Helps the body to get rid of harmful substances.
- Nervous system: Lets us have the ability to feel, hear, smell and taste.
- Reproductive system: Makes us give birth for new individuals.

The human digestive system:
Digestion:
Changing the food from a complex form into a simple one to let the body get benefit.
The digestive system:
Is the system which is responsible for digesting food.

The digestive system consists of two main parts which are:
A- Alimentary canal:
A set of organs which contact with each other in a shape of along pipe (duct) known as the digestive canal. (9-10) meters.
It consists of:
1.Mouth
2.Pharynx
3.Oesophagus
4.Stomach
5.Small intestine
6.Large intestine
7.Anus
B- Alimentary canal accessories (associates):
They secrete juices and enzymes, which help in the digestion process.
They include:
1. Salivary glands
2. Liver
3. Pancreas
The human digestive system:
(1): Mouth:
Is a cavity in where teeth and tongue are exited and the salivary glands open to it as well.
: It is the first organ of the digestive system it contains
1- Tongue:
It upturns food inside the mouth cavity and mixes it up with saliva assisting the process of good swallowing and taste.
2- Teeth:
- Chew the food.
- They are 32 in an adult, each jaw has 16 teeth divided into (4 incisors, 2 canines and 10 molars):
I- Incisors and canines: cut and tear food into small pieces.
II-Molars: grind the food to ease its swallowing process.
3- Salivary glands:
They are three pairs of glands secrete a liquid known as the saliva which digest starches then convert them into sugar.

(2): Pharynx:
- It is a common cavity extending leads to the oesophagus and trachea.
- It permits food to pass from the mouth to the oesophagus.

(3): Oesophagus:
- It is a muscular tube that the food travels thought from the mouth to the stomach.
- It allows food to pass from the pharynx to the stomach.

(4): Stomach:
- It is a sac-like muscular organ.
- "1" it works on "mixing food up" by its digestive juices (food changes into semi-liquid substances)
- "2" it secrets "gastric juice" that digests "proteins" into simple water "soluble substances".

(5): Small intestine (ileum):
- Its length is about 7 "meters".
- It coils (lies) inside the "abdominal cavity".
- It starts with a part known as "duodenum".
- "Duodenum" is followed by a part of the small intestine called (ileum) because it is a long convoluted tube.
- It digests food completely.
- Absorption process takes place in the small intestine walls then it
delivers the blood which distributes it all over the body organs.
Food is completely digested in the small intestine by the help of:
1- Intestinal Juice:
- From the small intestine.
- Poured in the (ileum).
2- Bile Juice:
- From the liver and it is stored in gall bladder.
- Poured in the duodenum.
3- Pancreatic Juice:
- From the pancreas.
- Poured in the duodenum.

(6): Large intestine:
- It is an inverted U-shaped tube.
- It starts from the end of small intestine ending in the anus which is located at the end of the rectum.
- "1" Water is absorbed in rectum from food remains, then these wastes are rejected outside the body through anus.
Keeping the digestive system healthy:
"To keep your digestive system healthy you have to follow the following instructions":
1.Chew the food well.
2.Don't eat much food that contains large amounts of fats such as fast meals.
3.Skip having food containing the additive compounds and flavorings.
4.Skip purchasing food from streets to avoid infectious diseases.
5.Practice sports regularly.

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* The cell is the building unit of the living organism's body.
* Animal cell is the building unit of the animal body, and the plant cell is the building unit of the plant.
- A group of identical cells form a (tissue).
- A group of tissues form an (organ).
- A group of organs form a (system).
- A group of (systems) form a living organism's body.
Cells are units that differ in shape and size according to their locations and functions.

The cell simplified structure :
All cells are units contain :
1- Nucleus: Organizes the biological operations inside the cell and it is in charge of cell division.
2- Cytoplasm: Fills the space and biological operations are acted by it.
3- Plasma membrane: surrounds the cell and controls the substances entering into the cell or leaving it.


"The plant cell" is characterized by the "presences" of a "cell wall"
surrounding it and contains "chloroplasts" which are "responsible for
making" food in a process which known as "photosynthesis".

Unicellular organisms :
- There are a lot of (unicellular micro organisms) around us which can
not be seen by the naked eye such as (bacteria) and (yeast).
- The unicellular organism is considered as (an integrated living thing)
has the ability to do all the (biological functions) and it is a model
to the cell ability as a unit of structure and functions of a living
organism's body.

Yeast fungus Examination :

Structure of yeast fungus:
It is an unicellular living organism that made up of:
1. Nucleus
2. Cytoplasm
3. Cell wall
Economic importance of the yeast fungus:
1. Making Bread
2. Making alcohol

- Life on earth depends on sunlight because it is important for plants to make their own food.
- Sun is the main source of heat and light for all living organisms.
- Green plants can make its food by photosynthesis the necessary conditions for photosynthesis:
1. Sunlight
2. Green substance in plant (chlorophyll).
3. Water
4. Carbon dioxide gas
- The products of photosynthesis:
1. Starch(food)
2. Oxygen
- Photosynthesis is important for life as it gives us food and oxygen.
Kinds of living organisms:
Living organisms are classified into:
1- Producers:
Living organisms that can make their own food through process of photosynthesis.
Ex: Green plants
Importance give us food and oxygen.
2- Consumers:
Living organisms depending on producer's t to get their food directly or indirectly.
Ex: Human - cows - lions - chicken - sharks.
3- Decomposers:
Living organisms can't make their food they can get food by decomposing
the organic wastes such as dead bodies of plants or animals.
Ex: some types of bacteria and fungi.
Importance: increases soil fertility - get rid of dead organisms.

- Living organisms need food to get energy.
- Food chain: the path of energy transmits in form of food from living organisms to another.
Note:

Food chain starts with (producers) and ends with (decomposers).
Ex:
Green plant --> rabbit --> snake --> Hawk --> die --> decompose.
The food web:

Group of food chains connected together



* Many objects around us are observed to be in state of motion (like) running man or ball, others are in state of stability.
* To change the state of body from rest to motion or from motion to rest we need (force).



Force:
An effect that changes the state of object. Measuring unit of force is (Newton).
- Some games depend on force like (ballon) and (rocket).
- Force causes the motion of objects and their rising.
- Some technological applications depend on force like: mixer - electric fan - cars - train.
- Some applications that their operations depend on the effect of force are:
1. Crane
2. Electric left
3. Pulleys
4. Electric ladder




Motion:
Is the change in body position related to time.



The speed:
It is the distance that is travelled:
- By an object in one second in a certain direction.
- The unit of measuring speed is meter/second.
- The relation between pushing force and speed by increasing the pushing force the speed of body increase.
So speed is directly proportional with pushing force.



The role of scientists:

A- Arab scientists:
Ibn Younis El Masri

Discovered the watch pendulum.
Badea El Zaman.

- Born in twelfth century
- He was pioneer in water tools industy.

B- Western scientists:
Gims Watt:

- Invented steam engine.
- Leader of industrial revolution.
Isaac Newton:

- Put Gravity law.
- Made reflecting telescope.



Energy:
Is the ability to do work or (make a change).



Example:
- The player has energy to make sports and lift up heavy loads.
- The seller pushes his cart on road.



Energy has many forms:
1- Potential energy:

Energy stored in body due to position.
Ex: Spring of toy.
2- Kinetic energy:

Energy stored due to movement of bodies.
Ex: Moving car.
3- Light energy:

Energy of light.
Ex: Lamp
4- Electric energy:

Energy produced from electricity.
5- Heat energy:

Energy from heat.



Changes of energy:
Energy can be converted from one form to another.
Ex:
- Rubbing hands' Change kinetic energy to heat energy.
- Toying spring of Toy ---> Kinetic to potential.
- Electric heater ---> Electric to heat.
- Electric motor ---> Electric to kinetic.
- Electric Lamp ---> Electric to light.
- Hitting drum ---> Kinetic to sound.
- Dynamo ---> Kinetic to electric.
- Dry cell ---> Change chemical to electric.
- Solar cells ---> Solar energy to electric energy.
- Photosynthesis ---> light to chemical.




* Sun is the main source of energy on earth.

Importance of sun:
1. Source of heat and light.
2. Warming water by solar heaters.
3. Photosynthesis for green plants.
4. Formation of wind, clouds and rain.
5. Getting electricity by solar cells.
- Sun evaporates water from sea and oceans then the water vapour condenses in atmosphere causing clouds.
- Sun causes the movement of winds.
- Sun is the main reason for formation of fuel (petroleum and coal)
under the earth surface from the plants and animals buried under it.
- Sun is the main source of energies on the surface of earth.
- If there is no sun, life will not be exist.
- The renewable sources of energy are:
1. Wind: by wind mills to get electricity.
2. Rising of ebb and tides: by turbines to produce electricity.
3. Water falls: by moving turbines to generate electricity.
- The non- renewable sources of energy:
1. Coal
2. Petroleum
3. Natural gas
Used in getting energy to move cars , trains , aeroplanes by Benzine - Kerosene or naturals gas