PC3 Revision Flashcards
What are the differences between light and sound?
Light is a transverse wave and sound is a longitudinal wave. Light travels at 300,000,00m/s and sound travels at 330m/s
What is reflection ?
When light bounces off a surface back to the medium it came from
Why does refraction occur?
The speed of light Changes as it moves from one medium to another
What are the primary colours of light
Blue, Green and Red
DESCRIBE THE STRUCTURE OF THE EYE- NOTEBOOK
DESCRIBE THE STRUCTURE OF THE EAR- NOTEBOOK
What is ultrasound.?
ultrasounds use sound waves to make pictures of the body.
State a property of a solid
Any answers from the following:
It cannot be compressed
It cannot change shape easily
It cannot flow
It has a fixed volume
State a property of a liquid
Any answer from the following:
It cannot be compressed
It can change shape easily
It can flow
It has a fixed volume
State of property of a gas
Any answer from the following:
It can be compressed easily
It can easily change shape
It can flow
It will spread out in a container to fill all available space
It has a volume that can change
Stay at the four changes of state
Melting
Evaporating
Condensing
Freezing
In which state do the particles have the highest density?
Solid
What is the definition of diffusion?
Diffusion is the movement of gas particles or particles in a solution from a high concentration to a lower concentration
What is Brownian motion?
The random movement displayed by small particles that are suspended in fluids
What causes gas pressure?
Gas pressure is caused by particles colliding with the walls of the container 
What is a cell
The smallest unit that can live on its own, and that makes up all living organisms
What is a tissue?
A group of cells that are similar and work together to perform a certain function
What is an organ?
Many different tissues working together
Describe the skeletal system
The organ system that supports the body, gives it shape, protects internal organs , allows movement and produces broad blood cells
Describe the muscular system
An organ system consisting of skeletal smooth, cardiac muscle. It permit movement of the body.
Name the parts of the respiratory system
Nose/mouth, trachea., bronchi, lungs, bronchioles, alveoli
Explain how gas exchange occurs
Oxygen moves from the lungs to the bloodstream at the same time carbon dioxide passes from the blood to the lungs
What is a drug?
Chemical substance that has an effect on the body
What is asthma?
A disease in which the bronchial airways in the lungs become narrowed and swollen, making it difficult to breathe
What are the harmful effects of smoking?
Smoking can cause lung diseases by damaging your airways, and the alveoli are found in your lungs
What is the difference between mass and weight?
Maths is the amount of matter in an object and weight is the force of gravity acting on a mass
What is an orbit?
The curved path of one object around another 
List the planets in the Solar System in order.
Mercury, Venus Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
What causes days and nights
The Earth rotates once every 24 hours on its axis
Why do we experience seasons?
The earths axis is tilted as it travels around the Sun some parts receive more sunlight each day than others
What is an eclipse?
Eclipses caused when an object in space, obscures the light from another object in space
What is the difference between an acid and an alkali
An acid will turn red, orange, yellow and have a ph level less than 7 and an alkali will turn blue, purple and have a ph level of greater than 7
What is an indicator
A substance that will change colour specific pH value
What is neutralisation?
The process of removing acidity or alkalinity by reacting an acid and an alkali together
What gas is made when a metal reacts with an acid?
Hydrogen
What are the contents of a healthy human diet?
Carbohydrates
Lipids
Proteins
Vitamins
Minerals
Fibre
Water
What is malnutrition?
Lacking in a specific nutrient
How do we test for starch?
Add two drops of iodine to the sample if starch is present, it will turn black/blue
Name in order that organs that food passes through
Mouth, oesophagus, stomach, small intestine, large intestine, rectum and anus
What do enzymes do?
Enzymes help speed up the chemical reactions in our body
What happens in the intestines?
In the small intestine digested food is absorbed into the blood.
The large intestine absorbs water and changes the waste from liquid into stool
How many loops does a series circuit contain?
One
How many loops does a parallel circuit contain?
More than one
What does resistance do?
Slows down current in a circuit
What is resistance measured in?
Ohms
What is ohms law?
Voltage= Current x Resistance
