Science Core Knowledge
Year 9
This booklet contains the core knowledge that we believe is the foundation of understanding for each of
the topics taught in year 9.
Pupils are require to learn a selection of these questions each week for homework. Their teacher will then
carry out regular quizzes to check pupil progress.
The first 10 questions in end of topic tests will always come directly from this booklet so that pupils who
have applied themselves to revision will always be rewarded by predicable questions.
We suggest that pupils work with each other or with adults at home to memorise a few at a time in much
the same way you may have prepared for spelling tests in the past.
To help prepare for the end of topic tests we have created a website that contains digital copies of these
questions, the presentations that teachers use in their lessons, links to other websites, details of test
dates and other things you may find useful.
bit.ly/aylshamscience
(You will need to type this in to the the address bar exactly as is because the site is hidden from Google.)
We also sell CGP KS3 revision guides from room 10 at lunch or break time at a significantly reduced price.
9.1 Genetics
1
2
Question
What is variation?
16
Name a feature of humans that shows
continuous variation
Name a feature of humans that shows
discontinuous variation
Name two reasons for variation within a
species
What causes genetic variation?
What causes environmental variation?
What is contained in the nucleus of a cell?
What are DNA strands stored as in the
nucleus?
What is the name for a part of a
chromosome that contains information for
a particular characteristic or set of
characteristics?
Name the four scientists that discovered
the structure of DNA
How do antibiotic resistant bacteria
provide new evidence for Darwin’s theory
of natural selection?
What is interspecific competition?
What is intraspecific competition?
When is a species considered to be
extinct?
Why do some living things become
extinct?
What is natural selection?
17
What is selective breeding?
18
What is cloning?
19
What are the advantages of golden rice
production?
3
4
5
6
7
8
9
10
11
12
13
14
15
Answer
All individuals in a population differ slightly from one
another
Height, Weight, Arm span, hand span, length of foot
Eye colour, shoe size, hair colour, gender
Genetic variation and Environmental variation.
Sexual reproduction and mutation of DNA
Characteristics acquired from an organisms environment
DNA
Chromosomes
A Gene
Watson, Crick, Franklin and Wilkins
They show how natural selection can happen in short
periods of time
Competition between organisms of different species
Competition between organisms within a species
When there are no living organisms of that species left.
The organism fails to adapt to rapid changes in it’s
environment.
Individuals with characteristics most suited to their
environment are more likely to survive and reproduce.
Those that are poorly adapted to their environment are
less likely to survive and reproduce.
Where humans breed plants and animals for particular
characteristics.
Asexual reproduction that produces genetically identical
cells
Advantages:
Prevent people from suffering from a lack of vitamin A
and so can prevent death from a poor immune system
and prevent blindness
May cross-breed with wild rice plants and contaminate
the wild rice DNA
Worries that eating GM organisms may harm people (no
evidence of this)
Expensive to buy
Do not produce fertile seed so new plants need to be
brought by farmers every year
1
20
What are the disadvantages of golden rice
production?
Disadvantages:
May cross-breed with wild rice plants and contaminate
the wild rice DNA
Worries that eating GM organisms may harm people (no
evidence of this)
Expensive to buy
Do not produce fertile seed so new plants need to be
brought by farmers every year
9.2 Health
Word
Definition
The process which the cells in your body use to produce
energy.
This is respiration using oxygen.
e.g.
glucose + oxygen  Carbon + water + energy
dioxide
Respiration without oxygen. This produces less energy
than aerobic respiration
e.g.
glucose  lactic acid + energy
1
Respiration
2
Aerobic respiration
3
Anaerobic respiration in humans
4
Anaerobic respiration in microorganisms e.g.
yeast
5
Testing for carbon dioxide
6
Carbohydrates
Collect the gas and bubble it through limewater. If the
limewater goes cloudy the gas is carbon dioxide
Used by your body as a fuel.
7
Proteins
Used by your body for growth and repair
8
Lipids (fats)
Used by your body as a store of energy and to keep you
warm
9
Fibre
Used to help food move through your digestive system
10
Balanced diet
11
Obesity
12
Starvation
This is required for you to stay healthy. It will contain the
different types of nutrients listed above.
Happens when your body takes in more energy than you
use. The extra energy is stored as fat. Obesity can lead to
heart disease and high blood pressure.
Happens when your body does not get enough energy.
This can affect your growth and make you more likely to
get infections.
Lactic acid can build up in your muscles and cause cramp.
This reaction can be used in fermentation to make
ethanol (alcohol).
e.g.
glucose  carbon dioxide + ethanol + energy
2
13
Skeleton functions
14
Antagonistic Muscles
15
16
17
Contracting muscle
Tendon
Diaphragm
18
Alveoli
19
Nicotine
20
Tar
1. Protection e.g. skull protects your brain
2. Support – provides a structure which allows you to
stand up
3. Movement – muscles attached to bones cause your
skeleton to move at joints
4. Blood cells – bones contain bone marrow which
produces red blood cells (carries oxygen around your
body) and white blood cells (protect you from infection)
Muscles work in pairs against each other. When one
muscle contracts the other relaxes e.g. bicep and tricep in
your arm.
The muscle becomes smaller
Attaches the muscle to a bone.
A muscle underneath the lungs which moves up and
down to help air in and out of your lungs.
Small sacs in your lungs where oxygen is taken in to your
blood stream and carbon dioxide moves out of your
blood stream.
This is an addictive chemical in cigarettes which makes it
difficult to stop smoking.
The tar damages cilia in your airways which stops the cilia
from working. This causes a mucus to build up which
makes you cough. This can lead to emphysema.
9.3 Reactivity
Word
1
2
3
4
5
6
7
8
9
10
11
12
13
What pH range do acids have?
What pH range do alkalis have?
What happens when we add an acid to an
alkali?
What element do all acids contain?
When an acid and an alkali react what are
the products?
What type of salt does nitric acid produce?
What type of salt does sulfuric acid
produce?
What type of salt does hydrochloric acid
produce?
What is produced when we react a metal
with oxygen?
What is the gas in air required to produce
a metal oxide
What is oxidation
What is reduction
What is produced when a metal oxide
reacts with an acid?
Definition
1-6
8-14
They neutralise each other
Hydrogen
A salt and water
Nitrates
Sulfates
Chlorides
A metal oxide
Oxygen
Gaining oxygen
Losing oxygen
A salt and water
3
14
15
16
17
What is produced when a metal reacts
with an acid?
What is the test for hydrogen
Iron rusting is an example of…
Give three ways to prevent oxidation
18
What is displacement?
19
What is the reactivity series?
20
What is an ore?
21
What is used to extract (reduce) iron form
its ore?
Why can’t carbon be used to extract
magnesium?
What could be used to extract
magnesium?
What is the formula for calcium
carbonate?
What is produced if we heat a metal
carbonate?
What is a catalyst?
22
23
24
25
26
A salt and hydrogen
Lighting the gas produces a squeaky pop
Iron rusting
Use a less reactive metal
Paint the metal
Cover in oil
Use a sacrificial anode
Where the more reactive metal replaces a less
reactive metal
A list of metals with the most reactive at the top and
the least reactive at the bottom
A rock with enough metal in to make it worth
extracting
Carbon (coke)
It is not reactive enough
Electricity
CaCO3
A metal oxide and carbon dioxide
Something that speeds up a reaction without being
used up itself
4
9.4 Fuels
1
What happens to the particles in a substance in a chemical
reaction?
List three chemical reactions.
2
3
What happens to the particles in a substance in a physical
reaction?
List three physical reactions.
4
What is an endothermic reaction?
5
What is an exothermic reaction?
6
What is thermal decomposition?
7
Give an example of a thermal decomposition.
8
What is oxidation?
9
What is combustion?
10
What is corrosion?
11
What is neutralisation?
12
13
What is crude oil?
What is a hydrocarbon?
14
What is an alkane?
15
What is an alkene?
16
What are conditions for the formation of crude oil?
17
18
How is crude oil processed to make it useful?
What is cracking?
19
What are the products of fractional distillation used for?
20
What is a fuel?
21
What is a polymer?
22
How are polymers made?
23
During a chemical reaction the atoms in the molecules
rearrange to form new molecules, with new properties.
Corrosion, combustion and neutralisations are all chemical
reactions.
During a physical reaction no new chemicals are made but the
way a chemical looks changes.
Melting, boiling, condensation, freezing and sublimation are
all physical changes.
An endothermic reaction is a reaction that absorbs heat as it
progresses. The surroundings get colder.
An exothermic reaction is a reaction that gives off heat as it
progresses. The surroundings get hotter.
Thermal decomposition occurs when a chemical decomposes
when it is heat.
Calcium carbonate decomposes to form carbon dioxide and
calcium oxide.
When a chemical reacts with oxygen, the process is called
oxidation.
When a fuel reacts with oxygen, the process is called
combustion.
When a metal reacts with oxygen, the process is called
corrosion, all metals corrode but when iron corrodes we call it
rusting.
When an acid and an alkali react to form a neutral solution
this process is called neutralisation. The products are a
neutral salt and water.
Crude oil is an unrefined mixture of hydrocarbons.
A hydrocarbon is a chemical that is only made of carbon and
hydrogen atoms.
Alkanes are saturated hydrocarbons. All the atoms are joined
by single bonds.
Alkenes are unsaturated hydrocarbons. Some atoms are
joined by single bonds and some are joined with double
bonds.
The remains of microscopic marine life are buried and
subjected to heat and pressure over millions of years.
Crude oil is fractionally distilled.
Cracking is the process that breaks large hydrocarbons into
smaller more useful molecules
The products of fractional distillation are used as fuels and as
raw materials for other reactions.
A fuel is a substance that releases energy when it reacts with
oxygen.
A polymer is a long chained molecule, that is made by joining
many monomers together.
Polymers are made from joining monomers together into
long chains.
Name four polymers?
24
Polyethene, polypropene, polystyrene and polychloroethene
5
9.5 Electricity
Number
1
Question
What is voltage?
2
What happens in a step-down transformer
and why are they used in the national grid?
3
4
Describe direct current
Describe how to induce a current in a wire
5
If the potential difference at V1 and V2 is 5V,
what is the voltage at V3?
6
7
State the equation for calculating power
What is the current flowing through a 20W
device if the potential difference across it is
5v?
8
9
How is a voltmeter placed in a circuit?
What is potential difference
10
Describe what happens to current in a parallel
circuit
If the current flowing through ha bulb is 3A
and the potential difference across it is 6V,
what is the resistance of the bulb?
11
12
If the current at A1 is 5A, what is the current
at A2 and A3?
6
Answer
The amount energy provided by a battery or cell
in a circuit
A step down transformer has more coils of wire
on the primary arm, which decreases the voltage
but increases the current. They are placed before
homes so the risk of electrocution is reduced,
making it safer.
Electrons flow in one direction
By moving a wire in a magnetic field, or by
moving a magnet in and out of a coil of wire
5V
Power = current x voltage
Equation: power = current x voltage
Rearrange: current = power / voltage
Substitute: current = 20 / 5
Calculation: 20 / 5
Units: current: = 4A
Parallel across a component
The energy difference across a component, also
known as voltage
The current splits and recombines at junctions
Equation: resistance = potential difference /
current
Substitute: resistance = 6 / 3
Calculation: 6 / 3 = 2
Units: resistance = 2
A2 = 5A
A3 = 5A
13
14
State the equation for calculating resistance
What happens to the potential difference in a
parallel circuit at each branch?
15
What happens in a step-up transformer, and
why are they used in the national grid?
16
17
Describe what current is
Describe how electricity is generated
18
What is a transformer, and how do they work?
19
What is the unit of potential difference, and
what device measures this in a circuit?
What is the power across a light bulb that has
10A flowing through it and a potential
difference of 4V?
20
21
22
23
An efficient machine…
Describe what happens to the current as it
flows around a series circuit
Explain what happens to resistance as the
wire becomes hotter
24
What is the current for A1 and A2, if the
current for A4 is 10A and A3 is 6A?
25
State the unit of current and how it is measure
in a circuit
How is an ammeter placed in a circuit?
26
7
Resistance = potential difference / current
The potential difference at each branch is the
same as the potential difference provided by the
battery or cell
Step up transformers have an increased number
of wires on the secondary arm, this decreases the
current and increases the voltage. This is to make
the transfer of electricity over large distances
more efficient as it wastes less electricity
transferred into thermal energy.
The flow of electrons in a circuit
Water is heated in the boiler, either from nuclear
energy or from burning fossil fuels; this turns the
water into steam. The steam turns the turbine,
which turns a coil wire in a magnetic field. This
induces an electrical current in the wire.
Transformers are made of an iron core with coils
of wires on 2 arms. The number of wires on each
arm can be changed to affect the voltage coming
out of the transformer, increase the number of
wires on the secondary arm to increase the
voltage being transferred out of the transformer.
Volts, V; a voltmeter
Equation: power = current x voltage
Substitute: power = 10 x 4
Calculation: 10 x 4 = 40
Units: 40W
Does not waste much energy
The current stays the same as it flows around a
series circuit
As the wire becomes hotter, the metal ions
vibrate more. This causes an increase of collisions
with the flowing electrons, and decreases the
rate of electron flow. This is a decrease in
current.
A1 = 10A
A2 = 4A
Amps, A; using an ammeter
In series
27
Describe alternating current
28
What happens to the potential difference in a
series circuit when you add more
components?
State three factors which can affect resistance
29
30
Calculate the voltage across a component if
the current flowing through it is 12A and the
resistance is 3
Electrons fluctuate back and forth many times a
second
The potential difference decreases as you add
more components to a series circuit
Length of wire, thickness of wire, type of metal,
temperature of wire.
Equation: resistance = potential difference /
current
Rearrange: potential difference = current x
resistance
Substitute: potential difference = 12 x 3
Calculation: 12 x 3
Units: potential difference = 36V
9.6 Energy and Energy Transfer
Number
1
Question
What are forces, like weight, measured in?
2
3
What is the standard unit for mass?
What variables affect the attractive force of
gravity?
What are the two different units for gravity
and why are they different?
4
5
Why is mass a scalar quantity and weight
a vector quantity?
6
7
8
How do you calculate weight?
What is the unit for work done and how
does this unit relate to what it is equal to?
How do you calculate work done?
9
10
What is the standard unit for distance?
Describe the forces in a loaded spring
11
What materials obey Hooke’s law?
12
What is the point called where a material
permanently deforms?
Describe the movement of the particles in
a solid.
What does the pressure in a solid depend
on?
How can you calculate pressure?
What are the standard units for pressure?
13
14
15
16
8
Answer
Newtons (N).
Kg (kilograms)
Distance (between the objects) and mass (of
the objects)
m/s2 (metres per second per second) the
acceleration due to gravity, and N/kg
(newtons per kilogram) the gravitational field
strength.
Mass is the amount of matter. It is a scalar
quantity because it only has size (measured
in kg). Weight is a force due to gravity. It has
a size (measured in N) and a direction.
Mass x gravity
Joules (J) – work done is the same as energy
transferred.
Force x distance moved in the direction of the
force
Metres (m)
Weight acts downwards balanced by tension
upwards in the spring.
Materials like metal where the load and
extension are directly proportional
The elastic limit.
The particles are just vibrating in their fixed
positions, close together in nice neat rows.
Force (N) and contact area (m2).
Force/Area
Pascal (Pa) 1Pa = 1N/m2
17
18
19
20
Describe the movement of the particles in
a liquid.
What happens to pressure as you go
deeper down into a liquid?
How can pressure in liquids be useful?
How is the pressure of a gas related to the
motion of the particles?
21
What is the relationship between kinetic
energy of the particles in a gas, its
temperature and it’s pressure?
22
What is the relationship between volume
of a gas and its pressure, for a fixed mass
and temperature of gas?
If a seesaw is balanced what must be true
about the moments involved?
How do you calculate the moment or
turning force?
What unit is used for moments?
23
24
25
9
The particles are moving past one another,
close together in a random pattern.
It increases.
Hydraulic braking systems
As the particles get more kinetic energy they
move more. As the particles get faster they
hit the sides of the container more often and
harder. This causes an increase in pressure.
As a gas is heated up and temperature
increases the particles gain more energy.
With more kinetic energy the particles move
faster. This increases the pressure.
As the volume of a gas decreases, the
particles would hit the walls more often and
so the pressure would increase.
The clockwise and anticlockwise moments
must be equal.
Force x distance from pivot.
Nm or Ncm