Section 1 – KeywordsHypothesis - A proposal intended to explain certain facts or

observations

Independent Variable – What you change

Dependent Variable – What you measure

Control Variable – What you keep the same

Risk Assessment – Judging whether there are any hazards, what

the risk of them is and what safety precautions can reduce them

Hazard – Something with the potential to cause harm

Risk – The chance that the hazard may cause harm to people

Safety Precaution – A process to minimise the risk of a hazard

Method - Step by step instructions for how to complete an

experiment.

Results Table – Data recorded from your experiment of the values

of the dependent variables as you change the independent variable.

Graph - A visual representation of the relationship between the

independent and dependent variables.

Conclusion - summarises how your results support or

contradict your original hypothesis

Section 2 – Equipment

Section 3 – A labelled microscope Section 4 – A labelled Bunsen burner

Working Scientifically

Section 5 – How to use a Bunsen burner Section 6 – Chemical Reactions

Every chemical reaction has 3 parts:

Reactants → Products

Test for oxygen: A glowing wooden splint will relight.

Test for carbon dioxide: Causes limewater to turn cloudy.

Test for hydrogen: A light splint will make a popping sound.

Endothermic – Takes energy in from the environment

Exothermic – Releases energy to the environment

Solvent – a liquid able to dissolve a solute

Solute – the solid dissolved in a solvent

Solution - a liquid mixture of a solute dissolved in a solvent.

Section 7 – A model results table

Every results table should be drawn with a pencil and ruler and

include correct headings, correct units, and a mean column.

Section 8 – Model Graph

Every graph should include: axes drawn with a pencil and ruler and

then labelled (independent variable on the x axis, dependent variable

on the y axis); equal scale with units of measurement (2,4,6,8,10

NOT 2, 8, 12, 13, 16) a line of best fit (if it is a line graph) and finally,

a title.

Working Scientifically

Chapter 1 - Speed

Speed: How much distance is covered in how much time.

Equation: Speed (m/s) = distance (m) ÷ time (s). S = d ÷ t

Average speed: The overall distance travelled divided by the overall

time for a journey.

Acceleration: How quickly speed increases or decreases.

Relative motion: An objects speed is relative to the observers

speed.

Chapter 2 - GravityGravity: Every object exerts a gravitational force on every other

object because they have a mass.

Mass: The amount of stuff in an object (kg).

Weight: The force of gravity on an object (N).

Gravitational field strength: The force of gravity on 1kg (N/kg).

Gravity changes in size depending on the size of the planet you are

on e.g. Earth = 10 N/kg , the moon = 1.6 N/kg. There is less gravity

on the moon, so your weight is less even though your mass stays the

same.

Equation: Weight (N) = mass (kg) x gravitational field strength (N/kg)

Chapter 3 – Voltage and Resistance

Section 1Resistance: A property of a component , making it difficult for

charge to pass through, in ohms (Ω)

Equation: Resistance (Ω) = Potential difference (V) ÷ Current (A)

Potential difference (Voltage): The amount of energy shifted from

the battery to the moving charge, or from the charge to the circuit

components, in volts (V).

Electrical conductor: A material that allows current to flow through

it easily, and have a low resistance.

Electrical insulator: A material that does not allow current to flow

easily, and has a high resistance.

Chapter 3 – Voltage and Resistance

Section 2Effect of resistance: Components with resistance reduce the

current flowing and shift the energy to the surroundings in the form of

heat.

Chapter 1 to 3

Distance-time graphs

Straight line = constant speed

Curved line = acceleration

The higher the speed, the

shorter the time taken for a

journey

Example:

Earth weight = Mass x Gravity

Earth weight = 56kg x 10 N/kg

Earth weight = 560N

Moon weight = 56kg x 1.6 N/kg

Moon weight = 90N

Measuring voltage in series and parallel circuits

Voltage is shared in series circuits, reducing the

brightness of bulbs.Example:

Resistance = voltage ÷ current

Resistance = 20V ÷ 4A

Pressure = 5Ω

General rule for pressure: The

smaller the area, the greater the

pressure!

Voltage is NOT shared in

parallel circuits, so the

brightness of bulbs remain

the same.

Section 1 – Current in a series circuit

Current: is a movement of electrons and is the same everywhere in

a series circuit. Current divides between loops in a parallel circuit,

combines when the loops meet. It lights up bulbs and makes

components work.

Section 2 – Charged objects and their behaviour

Charged objects: around a charged object, the electric field effects

other charged objects, causing them to be attracted or repelled.

Field strength: The field strength around a charged object

decreases with distance.

Section 3 – What is an electrical circuit Section 4 – Key WordsNegatively charged: An object that has gained electrons as a result

of the charging process.

Positively charged: An object that has lost electrons as a result of

the charging process.

Electrons: Tiny particles which are part of atoms and carry a

negative charge.

Charged up: When materials are rubbed together, electrons move

from one surface to the other.

Electrostatic force: Non-contact force between two charged

objects.

Field: The area where other objects feel

an electrostatic force.

Chapter 4 -Current

Current: Flow of electric charge, in amperes (A).

In series: If components in a circuit are on the same loop.

In parallel: If some components are on separate loops.

Key fact: Two similarly charged objects repel.

Two differently charged objects attract.

Section 1 – What is energy?

All objects have internal energy. This includes:

• Energy caused by the movement of particles

• Energy due to the bonds between particles

As humans we get our energy from food. Our bodies release this

energy through respiration in our cells once our food has been

digested. The energy content of food is measured in Kilojoules (kJ)

and calories. This energy comes from three different food groups:

Section 2 – Renewable vs Non-Renewable

We get energy from many different types of energy resources,

including fuels and stores of energy such as batteries or the wind.

We can divide energy resources into two categories:

• Non-renewable energy resources cannot be replaced once they

have all been used up. E.g. Fossil fuels (coal, oil, gas)

• Renewable energy

resources can be

replaced and will

not run out.

E.g. Wind, water,

geothermal,

solar

Section 3 – Domestic Energy

Electricity is generated from a wide variety of both renewable and

non-renewable energy resources and is used throughout our homes

to do useful things.

For electrical devices their power is a measure of how much energy

they transfer in a certain time. Power is measured in Watts (W) and

1 watt is equal to transferring 1 joule of energy in 1 second.

You can calculate how much it would cost

To run an appliance for a certain amount

Of time using the following equation

Cost = power x time x price

• Power is measured in Kilowatts (kW)

• Time is measured in hours

• Price is measured in ( £per kWh)

Section 4 – Reducing Electricity Use

Other than their limited supply, fossil fuels have the disadvantage

that they release carbon dioxide which contributes to global warming.

In order to prevent climate change many governments have

committed to reducing their carbon dioxide production and overall

energy usage.

Methods of reducing the amount of electricity used include:

• Switching to renewable energy resources.

• Making appliances more efficient (do the same job using less

energy).

• Make sure buildings are well insulated so less energy is lost.

Chapter 5 –Energy Costs

Section 1 – Energy Stores

Energy can be stored in different ways including:

• Kinetic Energy – Any moving object

• Chemical Energy – Based on an objects internal energy.

• Gravitational Potential Energy – Any objected off of the floor.

• Elastic Potential Energy – Compression or stretching of an object.

• Electrostatic Energy – Based on electrical and magnetic fields.

• Thermal Energy – Based on an objects internal energy.

Section 2 – Energy Transfers

Energy can be transferred from one store to another in the following

ways:

• Heating e.g. metabolizing food

• Mechanically e.g. If an objects motion changes

• Electrically e.g. burning fuels

• Radiation.

You need to be able to identify what store the energy is in at any

point in a system and what methods of transfer it uses to move

between them.

Energy can be stored or transferred, but energy cannot be created or

destroyed. This means that the total energy of a system stays the

same. However in most systems some energy is dissipated into the

surroundings (it is shared in more energy stores).

Sankey Diagrams as shown on the right demonstrate how the input

energy on the left is transferred into useful energy (right) and

dissipated / wasted energy (down). In these diagrams the wasted

and useful energy should sum to make the total input energy.

We can increase how efficient a system is by reducing wasted

energy through friction or lack of insulation. People have previously

attempted to designed perpetual motion machines that will

continuously keep going without any extra energy being added. This

however is incredibly hard because there will always be friction.

Chapter 6 –Energy Transfer

Section 3 – Conservation of energy

Input

Energy

Wasted

Energy

Useful

Energy

Section 1a – Key WordsSound: Consists of vibrations which travel as longitudinal waves

through substances. The denser the medium, the faster sound

travels.

Speed of sound in air = 330m/s (a million times slower than light)

Sound does not travel in a vacuum (in space, no one can hear you

scream)

Vibration: A back and forth motion that repeats.

Longitudinal wave: Where the direction of vibration is the same as

that of the wave.

Volume: How loud or quiet a sound is, in decibels (dB).

Pitch: How low or high a sound is. A low (high) pitch sound has a

low (high) frequency.

Amplitude: The maximum amount of vibration, measured from the

middle position of the wave, in metres.

Wavelength: Distance between two corresponding points on a

wave, in metres.

Frequency: The number of waves produced in one second, in hertz.

Section 1b – Key Words

Vacuum: A space with no particles of matter in it.

Oscilloscope: Device able to view patterns of sound waves that

have been turned into electrical signals.

Absorption: When energy is transferred from sound to a material.

Auditory range: The lowest and highest frequencies that a type of

animal can hear.

Echo: Reflection of sound waves from a surface back to the listener.

Section 2 – Sound Wave BasicsYou need to explain observations of how sound travels using the

idea of a longitudinal and transverse wave.

Section 3- Sound Wave BehaviourYou need to explain observations where sound is reflected,

transmitted or absorbed by different media.

Chapter 7 -Sound

Section 1a – Key Words

Light: When a light ray meets a different medium, some of it is

absorbed and some reflected. For a mirror, the angle of incidence

equals the angle of reflection. Ray models can describe the

formation of an image in a mirror and how objects appear different

colours.

Incident ray: The incoming ray.

Reflected ray: The outgoing ray.

Normal line: From which angles are measured, at right angles to the

surface.

Angle of reflection: Between the normal and reflected ray.

Angle of incidence: Between the normal and incident ray.

Convex lens: A lens that is thicker in the middle which bends light

rays towards each other.

Concave lens: A lens that is thinner in the middle which spreads out

light rays.

Retina: Layer at the back of the eye with light detecting cells and

where image is formed

Section 1b – Key Words

Refraction: Change in the direction of light going from one material

into another.Absorption: When energy is transferred from light to a material.

Scattering: When light bounces off an object in all directions.

Transparent: A material that allows all light to pass through it.

Translucent: A material that allows some light to pass through it.

Opaque: A material that allows no light to pass through it.

Light travels at 300 million metres per second in a vacuum (the

fastest speed in the universe).

Section 2 – Light, Lenses and Eyes Section 4 – Light Wave Behaviour

When light enters a denser medium it bends towards the normal;

when it enters a less dense medium it bends away from the normal.

Refraction through lenses and prisms can be described using a ray

diagram as a model.

Chapter 8 - Light

Section 2 – Changes in State Section 3 – Diffusion and Gas Pressure

Diffusion:

Diffusion is when one substance (liquid or gas) spreads out from a

high concentration to a low concentration due to the random

movement of particles.

Pressure:

Pressure is caused by fluid (gas or liquid) trapped inside it, pushing

out on the walls of the container. This occurs because as the

particles move around randomly they collide with the container itself.

• The more particles trapped inside the greater the pressure

• The greater the temperature the greater the pressure

Chapter 9 -Mixtures

Solid LiquidGas

Gases:

• Particles are spread far

apart with large spaces

between them.

• Particles are arranged

randomly.

• There is little attraction

between the molecules

and only exert forces

on one another when

they collide.

• Molecules are in

constant and random

motion.

• Particles constantly

collide with each other

and with the walls of

the container.

Solids:

• The particles in the

solid are packed

closely together.

• The particles in a

solid often have a

regular

arrangement.

• These forces

between particles

are strong.

• Solids have a fixed

shape and do not

flow.

• The particles do not

move and are

limited to vibrating

in their positions.

Liquids:

• The particles in the

liquid are close

together.

• The particles are

arranged randomly.

• The forces of attraction

between particles are

stronger in liquids

compared to gases.

• Liquids have a volume

but no definite shape.

• These forces between

particles are weak

allowing liquids to flow.

Section 1 – Particle model of Solids, Liquids and Gases

Section 1 – Elements, Compounds, Mixtures

A- Compound – Contains more than one

element, chemically bonded together.

B- Mixture – Contains more than one elements not

chemically bonded together.

C- Element – only one type of atom

D- Element – only one type of atom

The graph on the left shows a pure

substance as the boiling curve

is smooth. Whereas the graph

on the right shows an impure

substance as the graph

continuously increases.

Section 2 - Solutions

Section 3 – Chromatography

And Filtration

Chromatography

What is it: A method of separating and analysing soluble chemical

substances

Method:

1. Draw a pencil line, on the bottom of a piece of paper

2. Add your samples along the line.

3. Place the bottom of the chromatography paper in water.

4. Let the water move up the paper separating your samples.

Filtration Set up:

What is it: Is used to separate

an insoluble solid from a solution,

producing a liquid filtrate and

leaving behind a solid residue.

Section 4 – Other Separation

Techniques

Distillation

What is it: Distillation is used to separate a solution using the

process of evaporation. Different parts of the solution boil at

different temperatures and then condense in the conical flask at the

end.

Set up:

Key word Meaning

Dissolve When a solute mixes completely with a solvent

SolubleProperty of a substance that will dissolve in a

liquid.

Solution Mixture formed when a solvent dissolves a solute.

SolventA substance, normally a liquid, that dissolves

another substance.

Solute A substance that can dissolve in a liquid.

Solubility How much solute can be dissolved in a solvent.

Chapter 10- Separation Techniques

Section 1 – The Periodic TableThe columns of the periodic table are called groups whilst the rows

are called periods.

• There are 18 groups in the periodic table.

• There are 7 periods in the periodic table.

Section 2 – Properties of metals and non-metalsMetals:

Non-metals:

Section 3 – Reactions

Metal + Acid → Salt + Hydrogen

E.g. Magnesium + nitric acid → magnesium nitrate + hydrogen

Use the squeaky pop test to check the gas is hydrogen

Metal + Oxygen → Metal Oxide

E.g. zinc + oxygen → zinc oxide

Metal Oxide’s have a pH above 7

Non-metal + Oxygen → Non-metal Oxide

E.g. Sulfur + Oxygen → Sulfur Dioxide

Non-metal oxides have a pH below 7

Section 4 – Reactivity

Elements are not all equally reactive. The picture below shows the

reactivity series where metals at the top are more reactive than

those below them.

In a chemical reaction, a more reactive metal will displace a less

reactive metal in what is known as a displacement reaction.

E.g. Magnesium + copper chloride → copper + magnesium chloride

Chapter 11 – Metals and Non-Metals

Section 1 – The pH scale

The pH scale is used to measure how acidic a chemical is. It runs

from pH 1 (strong acid) to pH 7 (neutral) to pH 14 (strong alkali).

We use special chemicals called indicators to determine if a

substance is acidic, alkaline or neutral. They turn different colours

depending on the pH.

Section 2 - Indicators

Indicators are chemicals that change colour depending on the pH of

the solution they are added to. There are two types of indicator,

narrow range and full range. Narrow range indicators (e.g. litmus

paper, phenolphthalein) only have two colours:

• Litmus paper is red in acid and blue in alkali

• Phenolphthalein is colourless in acid but pink in alkali

Full range indicator (e.g. Universal Indicator) have a different colour

for every pH as shown by the pH scale in section 1. It is also

possible to measure pH digitally using pH meters' as shown in this

picture.

Section 3 – Reactions Neutralisation Reactions:

Acid + Alkali → Salt + Water

E.g. Nitric acid + Sodium Hydroxide → Sodium nitrate + Water

A neutralisation reaction occurs when you react an acid with an

alkali. When complete the solution will be neutral, therefore at pH 7.

Acids and metal carbonates:

acid + metal carbonate → salt + water + carbon dioxide

E.g. Nitric acid + Sodium Carbonate → Sodium nitrate + Water +

Carbon Dioxide

When acids react with metal carbonates a neutralisation reaction

occurs. You can test if the gas produced is carbon dioxide by

bubbling the gas through limewater.

Section 4 – Naming Salts

The name of the salt is made up of two parts:

1. The name of the metal e.g. magnesium

2. The name of the acid (using the rules below)

E.g. Zinc+ Sulfuric Acid → Zinc Sulfate + Hydrogen

Chapter 12 –Acids and Alkalis

Section 1 – The Earth’s Structure

The Earth is on average 6371 km deep and is made up of 3 layers:

the crust; the mantle; and the core.

The Crust:

The crust is the solid outermost layer that

we stand on. The crust is thin but still

made up of different types of rock.

The Mantle:

The mantle is the very large layer between the crust and the core. It

is made up of semi-solid rock which flows very slowly over long

periods of time.

The Core:

It is thought that the core is made up of iron and nickel, however we

can’t be 100% sure. The core is divided into an inner solid section

and outer liquid section.

Section 2 – Types of Rock

Sedimentary Rocks: e.g. limestone, chalk and sandstone.

Sedimentary rocks are made from small particles which settle out

from slow moving water. This sediment is compressed by other

sediment falling on top of it causing it to appear as layers. Fossils

can be found in this type of rock.

Igneous rocks: e.g. granite, basalt, obsidian.

When molten rock is underground it is called magma, but when it

reaches the surface it is called lava. When this molten rock cools it

forms crystals, the slower it cools the larger the crystal. These

crystals formed are igneous rocks.

Metamorphic rocks: e.g. marble, slate and schist

Metamorphic rocks are formed when already existing rocks are

exposed to heat and pressure over long periods of time. This

causes the minerals in the rock to change.

Section 3 – Weathering The natural breakdown of rocks into smaller fragments is called

weathering.

Biological weathering is caused by living organisms. For example,

a tree may grow in a crack in some rocks and its roots can force the

crack to widen and a piece of rock to fall off.

Chemical weathering is caused by chemical reactions which wear

rock away. For example, rainwater is naturally acidic and can

dissolve limestone to make limestone caves. Burning fossil fuels is

making rainwater more acidic causing rapid chemical weathering.

Physical weathering doesn’t involve chemicals or living things. For

example, erosion, freeze-thaw weathering and onion-skin

weathering.

Section 4 – The Rock Cycle

https://www.youtube.com/watch?v=kXV7D89S9sc&t=5s

Chapter 13 –Earth Structure

Section 1 – The EarthThe Earth, like every other planet in our solar system orbits the Sun.

It takes the Earth 365.25 days to do this, also known as a year.

Earth also spins on its own axis, which is 23O from vertical. The time

it takes for one complete spin in 1 day. This is what causes the Sun

to rise in the East and set in the West.

The Seasons:

The combination of the Earth’s axis and its orbit around the Sun is

what generates the 4 seasons.

• When the northern hemisphere (north of the equator) is angled

towards the Sun, it is the northern summer.

• When the southern hemisphere (south of the equator) is angled

towards the Sun, it is northern winter.

This is because the light and heat from the Sun strike the surface of

the Earth more directly, so the weather is warmer and the days are

longer.

Section 2 – The Solar System• A celestial body is any object in space.

• All planets orbit the Sun in the same direction in the same plane,

and with the same shape (an ellipse).

• The further the planet is from the Sun, the longer it takes for it to

orbit the Sun, making its year longer.

Section 3 – The MoonThe lunar cycle lasts 28 days and is caused by the moon’s orbit

around the Earth. The moon can only reflect the light from the Sun,

therefore half the moon is always lit up, half is always in darkness.

The amount of Moon we can see depends on whether the side lit up

by the Sun faces the Earth or not.

Key Words:

• Waxing = increasing in size

• Waning = decreasing in size

• Crescent = less than half of the moon can be seen

• Gibbous = more than half of the moon can be seen

Section 4 – Beyond our Solar System

Distances in space:

• The Earth to the Sun = 150,000,000 km

• The Earth to the next closest star = 40,000,000,000,000 km

• An astronomical unit = 150,000,000 km

• A light year = 9,500,000,000,000 km

Exploring Space:

It is thought that there are at least 2 trillion galaxies in the

observable universe. The sun is one of an estimated 100-400 billion

stars in our Galaxy which is called the Milky Way. The Milky way is

approximately 100,000 light years in diameter, and is shaped like a

flattened spiral. We do not know what is at the centre of the milky

way but it could be a supermassive black hole.

It is very expensive and time-consuming to explore space because of

how far different celestial bodies are apart. Owing to this, The

furthest humans have ever gone is around the back of the moon.

Chapter 14 –Universe

Section 1 – Keywords

Joints: Places where bones meet.

Bone marrow: Tissue found inside some bones where new blood

cells are made.

Ligaments: Connect bones in joints.

Tendons: Connect muscles to bones.

Cartilage: Smooth tissue found at the end of bones, which reduces

friction between them.

Antagonistic muscle pair: Muscles working in unison to create

movement.

Muscular skeletal system: Muscles and bones working

together to cause movement and support the body.

Section 2 – The Skeleton

The skeleton is your body's internal framework of bone and

cartilage which supports your body. In order for your skeleton

to be strong and healthy, large amounts of calcium are required.

The skeleton has 4 main functions:

• Movement

• Protection of organs

• Supports our body weight

• Production of blood cells

Male and female human skeletons are not

the same with men having stronger, larger

Bones whilst female pelvis’s are larger to

help with child birth.

Section 3 – Muscles

Muscles are connected to bones by tendons and contract and

relax in order to allow you to move your bones and joints. Muscles

exist in antagonistic pairs e.g. biceps and triceps, because each

muscle can only control its contraction not relaxation. Some organs

(e.g. the intestines and the heart) contain muscles in order to

complete their function (push blood or food through your body).

Section 4 – Joints and Injuries

Types of joint:

• Synovial joints where the end of each bone is protected by

cartilage and synovial fluid to minimise friction and allow the joint

to move freely.

• Ball and socket joints, allow the greatest range of movement

• E.g. the shoulder and hips

• Pivot joint allow one bone to rotate around the other

• E.g. the wrist

• Hinge joints provide movement in two directions.

• E.g. elbow

• Fixed joints allow no movement

• e.g. skull

If joints or muscles become injured, then an individuals movement

can be hindered. Research is continuously being done to develop

new treatments, such as prosthetic joints which can restore

movement and reduce pain.

Chapter 15 -Movement

Section 1 – Keywords

Cell: The smallest unit of a living organism.

Tissue: Group of cells of one type.

Organ: Group of different tissues working together to carry out a job.

Organ system: A group of organs working together to perform one

or more functions

Cell membrane: Surrounds the cell and controls movement of

substances in and out.

Nucleus: Contains genetic material (DNA)

Vacuole: Area in a cell that contains liquid, and can be used by

plants to keep the cell rigid and store substances.

Mitochondria: Part of the cell where energy is released from food

molecules.

Cell wall: Strengthens the cell. In plant cells it is made of cellulose.

Chloroplast: Absorbs light energy so the plant can make food.

Cytoplasm: Jelly-like substance where chemical processes happen.

Vacuole: Area in a cell that contains liquid, and can be used by

plants to keep the cell rigid and store substances.

Section 2 – Cells

Cells are the building blocks of life and they enable organisms to

carry out the seven life processes (MRS GREN): Movement,

Reproduction, Sensitivity, Growth, Respiration, Excretion,

Nutrition.

Many organisms are uni-cellular (made up of only one cell). These

organisms often have flagella in order to allow them to move.

Section 3– Types of cellsThere are multiple types of

animal cells which all share some

common features demonstrated

in this diagram.

Although plant and animal cells

have large amounts in common,

plant cells contain some

organelles that animal cells do not.

Both animal and plant cells have

specialised features to allow them

to complete their function. Examples

of specialised cells include: sperm

cells, egg cells, nerve cells, root hair

cells, palisade cells, xylem cells and

phloem cells.

Section 4 – Organ Systems

Whilst some organisms are uni-cellular, others are multi-cellular

(made of many cells). For example an adult human is made up of 37

trillion cells.

These cells are organised in a particular way. Cells group together to

form tissues. Tissues group together to form organs. Organs

group together to form organ systems. Organ systems group

together to form organisms.

An example of an organ system is the digestive system, which is

made up of the oesophagus, stomach, liver, gall bladder, pancreas,

large intestine, small intestine and rectum working together to

digesting and absorbing food molecules.

Chapter 16 -Cells

Section 1 – Keywords Section 2 – Food Chains and Food Webs

A food chain is a series of organisms each dependent on the next

as a source of food.

Most organisms however eat more than one type of prey so

all of their food chains can be combined to make a food web.

Section 3 – InterdependenceMost organisms are hugely dependent on the other organisms in

their environment in order to survive. Insects are highly important in

most habitats because they complete key processes such as

pollination and nutrient recycling.

The populations of predators and prey are by nature dependent on

each other. If there are high numbers of prey, the predators will be

successful in hunting so can survive and reproduce causing their

numbers to increase. This increase in predator number leads to a

decrease in the prey population because of hunting. Owing to this

there are fewer prey to eat so predators die. Finally with few

predators, prey can survive for longer allowing their numbers to

increase again.

Section 4 – Factors affecting population size

There are multiple factors that affect population size.

Competition - Animals and plants have to compete for limited

resources (food, space, mates, shelter) . The best adapted animals

or plants will win and survive.

Disease - If a disease hits a population it can wipe out large

numbers very quickly. The more variation in a population, the more

likely the species will be able to survive the disease

Humans – Humans are having an increasingly strong affect on

population sizes of animals and plants. Activities such pollution,

deforestation, hunting and global warming are negatively impacted

habitats and making it harder for organisms to survive.

Chapter 17-Interdependence

Chapter 18 – Plant Reproduction

Section 1 – Parts of a Plant

Section 2 – Plant Cycle

Pollination:

Pollination occurs when

the pollen from the

anther (male part) is

transferred onto the

stigma (female part).

There are three ways

plants can be pollinated

• Wind Pollination

• Animal Pollination

• Water Pollination

Fertilisation:

Once the pollen has landed on the

stigma, it travels down the style into

the ovary. In the ovary the pollen

mixes with the egg to produce new

seeds.

Seed Dispersal:

In order to stop related plants

competing with one another seeds

are transported to grow in another

area. This can be done through the

following methods:

• Wind / Water dispersal

• Animal Dispersal

• Spinning Dispersal

Germination

If a seed lands in an

area where conditions

are good the seeds will

begin to develop new

shoots and roots. The

three conditions

required are:

• Water supply

• Oxygen

• Warmth

Section 1 – Keywords

• Species: A group of living organisms consisting of similar

individuals capable of producing fertile offspring.

• Variation: The differences within and between species.

• Continuous variation: Where differences between living things

can have any numerical value.

• Discontinuous variation: Where differences between living

things can only be grouped into categories.

• Interspecific variation: Differences between individuals of

different species.

• Intraspecific variation: Differences between individuals of the

same species.

• Habitat – The place where plants and animal live. Animals and

plants can find food, shelter and reproduce here.

• Environment - The surrounding in which plants and animals live.

Section 2 – Where does Variation come from?

Characteristics can be either inherited or environmental.

Inherited characteristics are features that we get passed down to

us from our parents. These characteristics are controlled by little bits

of DNA called genes. We get half of our genes from our mother and

half from our father.

E.g. Blood Group

Environmental characteristics are features that are determined by

how we live and the choices we make, for example what we eat and

where we live.

E.g. Hair Colour

Some characteristics can

be both e.g. Weight

Section 3 – Adaptations

Adaptations are features which allow an organism or species to

become better suited to its environment and habitat.

Adaptations can fall into 3 categories

• Anatomical adaptations are physical features such as an

animals shape.

• Behavioural adaptations can be inherited or learnt and

include tool use, language and swarming behaviour.

• Biochemical adaptations are those chemical processes that

occur within living organisms e.g. ability to regulate

temperature.

Section 4 – Natural Selection

Natural selection is differences in survival and reproduction

between individual of the same or different species based on their

individual adaptations. Those animals which survive and reproduce

are able to pass their DNA onto the next generation providing the

key mechanism of evolution of a population over time.

Animals and plants are now having to adapt to human caused

changes in the environment, especially the climate. Some animals

have undergone changes in their behaviour or anatomy, however

the most common change is where animals live. Many habitats like

the arctic and the rainforest are shrinking as a result of human

involvement meaning that many animals are increasingly

endangered.

Chapter 19 -Variation

Section 1 – Fertilisation Section 2 – Development of a baby

1. Once the gametes have fused, the joint cell is known as a

zygote.

2. The zygote begins to divide forming a ball of cells. These cells

are known as stem cells and have the potential to become any

type of cell.

3. Over the next couple of days, the zygote will reach the uterus

and will implant in the soft lining. It is now an embryo and

pregnancy begins.

4. After 8 weeks the embryo is called a foetus.

5. Finger–like projections grow into the uterus forming a plate like

structure called the placenta. In the placenta food and oxygen

diffuse from the mother’s blood to the fetus’ blood, and carbon

dioxide and waste products diffuse the other way.

6. The umbilical cord joins the fetus to the placenta.

7. The embryo continues to develop till it is, on average, 40 weeks

old, where the baby is born.

Section 3 – The menstrual cycleThe menstrual cycle is a series of events occurring in the females

reproductive system which last between 28-32 days approximately.

1. Day 1 to 7 - Menstruation (a period) occurs, where the soft

uterus lining breaks down and passes out of vagina with blood.

2. Day 7 to 14 - After menstruation, an egg starts to mature in the

ovary and the uterus lining starts to build up again.

3. Around Day 14 the – Ovulation (egg is released)

4. Day 14 to 28 - The egg is swept along the oviducts

towards the uterus.5. If the egg meets a sperm and is fertilised the woman

becomes pregnant and the cycle stops. If there is no

sperm cell the egg is not fertilised and the cycle starts

again with another ‘period’.

Section 4 – Fertility and contraception

Fertility is the ability to reproduce naturally as a result of sexual

intercourse. Not every is fertile and in 25% of cases of infertility a

reason cannot be identified.

The most common cause of infertility in men is poor-quality

semen, the fluid containing sperm that's ejaculated during sex.

Infertility in women is most commonly caused by problems with

ovulation. Fertility treatments e.g. IVF are used to increase the

chances of pregnancy, although they are not always successful. On

the other hand, because the treatment boosts the production of

mature eggs, multiple conceptions sometimes occur, with twins or

triplets being expected.

Contraception is the term given to all methods used to artificially

prevent pregnancy. There are hormonal forms of contraception

including the contraceptive pill, the implant and the injection, whilst

there are non-hormonal methods such as condoms and vasectomy.

Chapter 20 – Human Reproduction

Fertilisation is where DNA of

the sperm and ovum fuse

together creating a zygote

with a mix of the parents

DNA.