ELECTRICITY AND MAGNETISM

CURRENT ELECTRICITY

When an electrical charge moves in an electrical conductor we have current electricity. (Metals, such as copper)

An electric circuit is made up of different parts which are all connected together.

1.      -Generators: These supply the electricity

2.      Conductors: These are metals wires, which are covered in insulating material and let the electricity flow.

3.      Electrical components: These transform electricity into another form of energy light bulb transform into light.

4.      Switches: These open and close the electric circuit.

MAGNETISM

Magnetism is the ability to attract some metals. Magnets can be natural or man-made (Magnetite it`s an example of a natural magnet).All magnets have two poles. These are called the North Pole and the South Pole.

When two magnets touch at the poles, one of two things can happen:

·         If we put the same poles together, the magnets will repel each other.

·         If we put opposite poles together, the magnets will attract each other.

ENERGY SOURCES

Energy sources provide us with energy. There are two types of energy sources.

1.      Non-renewable energy sources. They can`t be replaced in our life time. Some example are: uranium used in nuclear power station, oil, coal, gas…

2.      Renewable energy sources. They can be replaced and never run out. Some examples are: Biomass, organic materials, sun light, wind, water, geothermal…

HUMAN BODY

TYPES OF JOINTS:

Fixed joints: This joints don`t move.

Semi-flexible joints: This joints allow a little movement.

Flexible joints: This joints allow our body to move.

Bones

Bones are hard and rigid they are made up of bones tissue. In our body there are 206 bones. They form our skeleton.

TYPES OF BONES:

Flat bones: Protect our internal organs.

Long bones: Are used for movement.

Short bones: Provide support and stability.

The skeleton

This skeleton`s function is to give shape and support our body and to protect the internal organs.

Muscles

Muscles are made up of muscles fibres and the muscles in our body respond to the nervous system by contracting and relaxing.

TIPES OF MUSCLES

Voluntary muscles: If you want to move them you can move them.

Involuntary muscles: you move them if you want or don`t want.

The nervous system

Definition: receives and respond to information from the five sense organs.

The central nervous system is made up of the brain, spinal cord and the peripheral nervous system which is made up of the nerves.

Central Nervous System

The brain is the control centre of the central nervous system and it`s made up of:

Cerebrum: it`s the biggest part of and control the voluntary movements.

Cerebellum: the cerebellum controls balance, movement and coordination.

Brain stem: the brain stem controls involuntary movement.

SPINAL CORD: The spinal cord it`s made up of nerve tissue and run from our brain down our spine.

REPRODUCTION

If a species doesn’t reproduce itself it will become extinct. When an animal reproduces it creates a new living thing it`s called offspring

Types of Reproduction:

Sexual reproduction

This method needs a male and a female of the same species. The ovum is fertilised by a sperm. An egg carried by the female is fertilised by a sperm from the male.

1.      Oviparous: the embryo grows outside the female body, inside an egg. The female lay eggs and these eggs are later hatch into new offspring.

2.      Viviparous: the embryo grows inside the mother’s body.

3.      Ovoviparous: These animals produce eggs, but the eggs develop and hatch inside the mother. Later the mother gives birth to live young.

Asexual reproduction

It`s when the offspring develop from a part of a parent’s body.

                                               THE FEMALE REPRODUCTIVE SYSTEM

1                    Ovum: the female sex cell. More than one ovum is called OVA.

2                    Ovary: produce the ovum.

3                    Uterus: the embryo develops inside.

4                    Fallopian tube: Connect the ovaries to the uterus.

5                    Vagina: It is a muscular tube that connects the uterus to the outside body.

6                    Vulva: the external part of the female reproductive system.

Male reproductive system

1.      Testes: produce male sex cells called sperm.

2.      Scrotum: It is a sac where the testes are located.

3.      Vas deferens: transport the sperm to the urethra

4.      Prostate gland: produce the semen. Semen carries sperm and gives its nutrients.

5.      Urethra: Is a tube in the penis.

6.      Penis: deposit the sperm

Puberty

Adolescence is the stage between childhood and being an adult. Adolescence is a time of physical, emotional and social change. Puberty takes place during adolescence. Puberty involves all the physical changes that change our body from a child’s body into the body of an adult.

We are born with primary sexual characteristics. They are male or female reproductive system. At puberty secondary reproductive system develop.

Male: male have lower voices and lots of facial body hair

Female: have wider hips grow hair in some places.

FERTILIZATION

Fertilization happens when an ovum and a sperm join to form a new cell called zygote. This cell contains information called genetic information. The offspring has information of the father and the mother.

Fertilisation takes place in the fallopian tube when the ovum is travelling from the ovary to the uterus. If fertilisation doesn’t happen the uterus expels the ovum trough the vagina. With small loss of blood called menstruation.

                                                             Living things

Living things: All the plant life in an ecosystem is called the flora. All the animal life in an ecosystem is caleld fauna. Other living things are fungi, microorganisms and bacteria.

The environment: Physical elements in an environment include air, water, soil, sunlight, temperature and climate.

Population: When population with each other they form a community.

One of the most important relationships involves energy. Energy moves through food chains and food webs elements in the food chain.

1 producers: make their own food.

2 consumers: they obtain the food by eating other living things.

2.1 primary: primary consumers eat producers.

2.2 Secondary: primary consumers eat producers.

2.3 Tertiary: tertiary consumers eat secondary consumers.

3 decomposers: decomposers decompose the remains of other living things.

Humans and ecosystems

Humans perform different activities that affect the environment.

Deforestation: consist in cutting down long areas of trees.

Contamination:

A)     Air contamination: is the use of fossil, fuels, petrol, coal …produce CO2. It incises the Earth’s temperature and causes the global warming.

B)     Water contamination It happens when waste from homes and indices It ben deposit in rivers, lakes …

C)     Sand contamination: Soil is polluted by chemicals from agriculture and waste from industries and homes.

Protection environment

People are trying to protect the enviroment.