Cells
What is the basic unit of life?
Cell
What is pressure measured in?
Pascals(Pa)
What is the unit of energy?
Joules
What is the iris?
The coloured part of the eye
State the neutralisation reaction:
acid+alkali-->salt+water
Give the names of two parts which are present in plant cells but not in animal cells
-chloroplasts
-cell wall
Examples of non-contact forces
Gravitational force
Electrostatic force
Magnetic force
What is radiation?
Energy that is radiated or transmitted in the form of rays or waves or particles.
Function of pupil
Controls the amount of light entering the eye
What 3 things are needed for combustion?
1)Fuel
2)Heating
3)Oxygen
Site of respiration
Mitochondria
What do air resistance and water resistance do to moving objects?
slow them down
Explain the steps of convection from 1-5
1. Liquids/Gas particles close to the heat source gain thermal energy 1st
2. These particles move faster and are less dense causing them to rise
3. Hotter water particles have risen to the top replaces the colder particles
4. Colder particles are more dense causing them to sink
5. These colder particles gain thermal energy and the process repeats
How are nerve impulses in the retina sent to the brain?
Along the optic nerve
Indigestion tablets neutralise acid in the stomach. What does this tell you about indigestion tablets?
They are alkali
Which type of cell traps micro-organisms to prevent diseases?
White blood cells
How to find the moment of a force?
moment= force x perpendicular force
An electric immersion heater is put at the bottom of a large tank of water. The water next to the heater becomes warm. What'll happen to the warmed water next to the heater?
It will rise
What happens to the light after it is passing through the cornea?
It is being refracted
How can you can increase the rate of a chemical reaction
1. Heat the reaction
2. Stir
3. Add a catalyst
How many different types of cells can be found inside the human body?
Explain why the pressure of water increases with depth?
Due to the weight of the water above
Why does convection only occur in fluids and not solids?
Convection is not possible in solids because for the convection to take place the particles of the substance should be free to move like fluids. The molecules of a solid are tightly packed together, thus making it difficult for particles to move around for convection to take place.
What are the 2 types of cells in the retina called?
Rod cells and cone cells
An open container has hydrochloric acid inside of it. You put magnesium inside. The reaction causes the magnesium to fizz. How will the mass inside the container change?
The mass is reduced as the gas being made is escaping the container as the container is open