SCIENCES

There are seven life process that all living things have and do, they are:

M = MOVEMENT

R = RESPIRATION

S = SENSITIVITY

G = GROWTH

R = REPRODUCTION

E = EXCRETION

N = NUTRITION

There are five specialised cells:

• the sperm cell - this is designed to fertilise eggs. Its head contains enzymes which allow it to digest to the cell membrane so the 2 nuclei can join.
• The ovum - designed to be ferilised by the sperm cell. The ovum is large and bulky because there is no movement needed. In the middle it contains a yolk to store the food for the young organisms once fertilised. It also carries chorosomes which carry genetic information.
• The palisade cell - designed for photosynthesis. this cell is tall with a large surface area which is good for absorbing sunlight which is needed for photosynthesis. They are packed with chloroplast which contains green chlorophyll.
• The cilated cell - designed to stop lung damage. They have tiny hair cells which filter the airas it blows through. The hairs sweep the dust and bacteria up the throat where its swallowed.
• The root hair - designed for absorbing. This long hair root cell increases the surface area helping it absorb water and minerals. It has a really thin wall so its easier for minerals to pass across the roots itself.

To have a balanced diet there are seven food groups you need:

• Carbohydrates - fuel for the body
• Proteins - vital for growth and to repair damaged areas
• Fats - acts as a store of energy when your body runs out of carbohydrates.
• Vitamins - only need small amounts they keep vital processes happening
• Minerals - meat (blood), calcium (bones/teeth), sodium (nerves), seafood (thyroid)
• Roughage - gives your digestive system an internal work out keeping it fit and working and healthy
• Water - About 75% of the body is water and all chemical reactions(e.g. digestion), take place in water - its really important.

Four important food tests:

• The iodine test for starch - Brown iodine mixed with food will turn blue/black if the food contains starch.
• The biuret test for protein - Add sodium hydroxide solution followed by weak copper sulphate solution. If the pale blue turns purple theres protein.
• The alcohol-emulsion test for Fats - Mix the food with ethanol then filter it. Add clear solution to water. A white emulsion means the food has fat in it.
• Benedict's test for simple sugars - heat benedict solution with food = orange precipitate indicates simple sugars are present.

Nearly all forces are pushes and pulls. Forces can't be seen but the effect of it can be seen. Forces comes in pairs(e.g. push/pull, thrust/air resistance) Forces make objects do five things.

• Speed up (like kicking a football)
• Slow down (like air resistance/drag)
• Change direction (hitting a ball with a bat)
• Turn (like turning a spanner)
• Change Shape (like streching, twisting, compressing, bending)

Two important statements of forces and movements:
BALANCED FORCES PRODUCE NO CHANGE IN MOVEMENT (AND)
UNBALANCED FORCES CHANGE THE SPEED AND/OR DIRECTION AND/OR SHAPE OF MOVING OBJECT

Force causes objects to turn around and pivot. Theres an important rule about levers:
THE LONGER THE LEVER, THE GREATER THE TURNING FORCE ABOUT THE PIVOT.

There are loads of everyday lever examples such as:

• getting lid off things
• opening doors
• scissors/cutting things
• using arms to pick things up
• Wheelborrows