Science Yr 10 Yearlies

7/30/2019 Science Yr 10 Yearlies

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Science Notes

Managing the Planet

Environment is made up of:BIOTIC refers to all the living things present in an ecosystem. E.g. trees, fungi, birds,insects etc.ABIOTIC refers to all the non-living factors.

Human ImpactUrbanization Loss of habitat for animals, natural habitat

loss adds to greenhouse effect, morepeople, less space

Introduce new species Loss of native animals, competition forfood, can be pests

Farming Salinity, plants cant keep up with water,use of pesticides/other chemicals

Removal of species Affects food chain/webs, loss of otherspecies

Mining Air pollution excess waste comes outlandslides earths surface loose movement, salinity

Mining and the Environment

Some forms of mining can leave large holes in the ground and removing

vegetation.

Damage to an ecosystem can threaten the habitats of animals and plants,

pollute water and air and leave piles of waste soil.

Rehabilitation seeds are collected and grown until they are mature enough to

be replanted in the holes left from earlier mines.

Air/water quality Environment Includes things like oxygen, CO2 H2O, temperature, soil, plants,

animals and foodBiotic living parts of an environment eg organismAbiotic Non living parts of an environment eg temp, oxygenEcosystem The non living and living parts of an environment make up an

ecosystemCycle A single complete execution of a periodically repeated phenomenon.Resource Its anything that we useRenewable A natural resource that can be used againNon-renewable

A natural resource that can eventually run out.

Fossil fuel something we burn that has been made from the remains of dead organisms overmany years.

Pollution It the contamination by unwanted substances.Greenhouseeffect

carbon dioxide, methane, and water vapour prevent heat from leaving the earth inthe same way glass prevents heat from leaving a greenhouse. As we add to thesegases, so the earth warms.


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Science Notes

The water cycle:

The carbon cycle:

Temperature Water Soil

Thermometer

Wind Speed Direction

Wind vane, anemometer

pH Water Soil

Universal indicator

Moisture Rainfall In soil

Hygrometer, wet and dry thermometer(humidity)Moisture meter

Air pressure BarometerRock type Observations and descriptionSalt level Dissolve in soil, evaporate in water %Pollution Oil spill, radiation, dioxins in water, gas

composition

TRANSPIRATI

CONDENSAT

PRECIPITAT

RUN

EVAPORATIO

INFILTRATI

GROUND WATER CYCLE

CO2

PLANTSS

ANIMALS

DECAY

RESPIRATION

PH

OTOSYNTH

ES

IS

RE

SPIRATIO

N

DEATH WITHOUTFOSSIL

BURN

COMBUSTION

EAT


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Science Notes

Radiation Not all types of radiation are harmful; examples include radio waves,

microwaves, and infrared.

Radiation is energy (waves or particles) radiating out from a source.

Bioaccumulation

Builds up in an organism

It will increase the substance as it moves up

in the food chain

Can affect the behaviour and physical health

of organisms

Over farming

Loss of top soil

Soil erosion

High levels of salinity

Mining

Cause deforestation

Loss of habitat

Trees cut down

Noise and air pollution

Chemicals can leak into water

Impacts of human activities on ecosystem:Introduction of a new species

Invasive plants can be weeds

Animals can consume native species

Reduce water quality

Increase soil erosion

Compete with native animals for food

Removal of a species

Can affect food web, distort it

Cause some species to over populate

Extinction of some species

Energy is important because we are totally reliant on it. We mainly use fossil fuels like coal,

oil to fuel our cars and to generate electricity.

Changes to protect the environment: taken lead out of petrol, most cars burn E10- burn

more efficiently, recycling, registration or laws to prohibit the dumping of materials, clean

water + air act.

94% of our energy comes from fossil fuels, non-renewable resources will run out.


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Science Notes Light, radiant heat (IR) and radio are all examples of radiation that is relatively

safe

Dangerous radiation is of the kind called ionising radiation. Examples are UV,X-rays and gamma rays.

Waves are carriers of energy. Earthquake waves carry a lot of energy.

Waves may be transverse or longitudinal.

TRANSVERSE (a) eg light and all other types of electromagneticradiation.

(b) the energy carried travels at right angles to thedirection of the vibration causing the wave.

(c) can travel through a vacuum does not need matter(d) all forms of electromagnetic radiation travel at the

same speed as light 300 000 km/sec.

LONGITUDINAL (a) eg sound which travels at 330 metres/second(b) requires matter ie particles are needed to vibrate(c) vibrations are along the direction of energy transfer(d) sound waves travel as a series of alternating

compressions and rarefactions.

Waves

Water waves carry energy, shown in the experiment with the cork.

Its also true for light and sound waves.

Earthquakes waves carry energy, which transmits from the focus to the

epicenter. (Primary, Secondary and Longitudinal).

Crest is the top of the wave, highest point

Trough is the bottom of the wave, lowest point

Amplitude is half the wave height Wavelength is the distance between two crests, measured in meters

Frequency The number of waves past a certain point in 1 second. (Measuredin hertz) High frequency = high pitch

Criteria Light Waves- electromagnetic Sound WavesWaveform Transverse waves (Matter moves

up and down which is right angle tothe direction the energy is moving)

Longitudinal waves (Movebackwards and forwards in the samedirection as the energy)

Speed 300 000 000 m/s 330 m/s 350 m/s depending ontemp.

Medium Light cant travel through opaqueobjects

Sound waves cant travel through avacuum, the need particles.

Light only travels in straight lines, can only be seen when it is reflected off an

object, can travel through a vacuum.

Reflection from the experiment, we discovered that the angle of incidence was

the same as the angle of reflection, within experimental error.

Internal Reflection: when light passes from one medium to another, not all

the light is refracted and some are reflected.

Total Internal Reflection: means that the light which strikes the surface istoo great of an angle and therefore no light is refracted (if angle is bigger than

critical angle)


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Science Notes

Lasers and optic fibers both require total internal reflection.

Uses ofconvex mirrors include: magnify objects; focus light onto a screen e.g.

projectors, cameras, telescopes, and microscopes.

Uses ofconcave mirrors include: often used with convex mirrors to give a

sharper image, torches, car headlights, make-up mirrors.

Refraction is the bending of waves. When light moves from one substance to

another at an angle the speed it is travelling at is changed, causing it to bend.

Moving from a less dense substance to a denser one slows light; this bends it

towards the normal. When it moves into a more dense substance it bends away

from the normal.

Moving from a dense substance to a less dense one slows light, this itbends towards the normal (line perpendicular to the flat surface

White light can be dispersed into a spectrum by passing it through a prism.

The electromagnetic spectrum is made up of all the types of radiantenergy. These vary in wavelength, frequency and amount of energy. Alltypes of em radiation travel at the same speed as light.

Lowest energy highest energy

Radioactive Elements

Radioactivity involves emission of particles and energy from nuclei.

Alpha: can be stopped by thick piece of paper, contains 2 protons and 2

neutrons, positively charges

Beta: can be reduced by piece of paper, or denser material, can be stopped by

thin aluminum sheet, high energy electrons, negatively charged

Gamma: almost stopped by thick pieces of lead sheets, high energy waves

Isotopes have an unstable nucleus, it can be either naturally or artificially made

Naturally occurring include: uranium-235 and carbon-14

Users: tracers to follow the movement of substances through liquid, (GAMMA)preserve food, kills microorganism in food. Natural radioisotopes can be used to

calculate the age of artifacts (radio-carbon dating), smoke detectors, soil

analysis, pollution testing, measuring thickness of objects, criminology.

Geiger counter can be used to measure radioactivity


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Science Notes Half-life: the time it takes for half the amount of radioactive isotopes to decay.

Some naturally radioactive elements are uranium, radium and polonium.

Uranium is used as a fuel in nuclear reactors.

Isotopes are atoms of the same element that have the same number ofprotons but different numbers of neutrons.

Radioisotope technology is used in the metal fabrication industry for

determining thickness of metals, in the energy industry to detect leaks ingas and petroleum pipelines and in medicine.

Uses of the electromagnetic spectrum in communicationEvery wireless technology has their own radio band. (e.g. Baby monitors: 49,

Garage door openers: around 40)

Microwaves are good for transmitting information from one place to another

because microwave energy can penetrate haze, light rain, snow, clouds andsmoke

Infrared is used in most TV, stereo and garage door remote controls. The con is

that you can only use it in direct line of sight to communication and you can

only connect one to one but its reliable as it is cheap, less chance ofinterference and it cant be intercepted.

Wave Type Wavelength

Uses Source Detectedby

Danger

Radio 2.8 to600m

Radio AstronomyListening to musicand radio

SunAstronomical objectsAM/FMtransmitters

AM/PMradiosGround-basedradiotelescopes

Noneknown

Microwaves

1mm to1m

MicrowaveastronomyCookingRadarCommunications

Gas cloudscollapsinginto starsMicrowaveOvensRadarstationsCell phones

Food(heated)CellphonesRadarsystemsMicrowavetelescopes

Highintensitiescan heatup livingcells andkill them.

Infrared 0.8 to10 microns

RestaurantsHospitals(sterilisation)Security cameras

PhotosynthesisLooking for youngstarsCommunication

FoodwarminglightsEverything

above roomtemperatureLasersBody heatSun, stars

TV remotes

Rattle-snakeseyes

Your skin

Nightvisiondevices

TVsDigitalcamerasPrinterswithinfraredreceivers

Highintensitiescan heatliving

tissuesand killthem.

Light micronto 0.6

Solar observationsLasers

VisionPhotography

SunLaser

PointersLight bulbs

CamerasHuman

EyeAnimaleyesPlants

Telescope

NoneCan cause

blindnessor burntissue athighintensity


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Science Notess

Ultraviolet 0.29 to 0.4microns

Attracting insectsStudying stars

TanningMineralidentification

Black LightBulbs

TanningBoothsSun

FlyinginsectsBlack andWhite filmUVcameras

CancerSkinburns

Tissuedamage

X-ray Length ofwatermoleculeto largeproteinmolecule

AstronomicalobservationsMedical DiagnosisSecurity Scanning

CAT scanmachinesRadioactivematerialsAirportluggagescanners

Space-based x-raydetectorsX.ray filmCCDdetectors

DNAmutationsHighdosescausedeathCan causecancer

GammaRays

< 0.0001nanometers

DetectingradioactivityDetecting nuclearweapon explosionsMedical treatments

RadioactivematerialsExplodingnuclearweaponsSolar flares

GammadetectorsonsatellitesMedicalimagingdetectors

CancerRadiationsickness

How the Eye Works

Light moves from an object to your eye and it passes through the cornea, which

is refracted by the lens and is focused at the retina. Also refracted by two fluids,then the image is upside down and it carried to the brain by optic nerves.

Note: Iris is a muscle that controls how much light enters the eye by expanding

and contracting. Muscles connected to the lens also expand and contract tocontrol the focus of image.

Choroid Most sensitive part of the retinaCornea Black layer with lots of blood vesselsVitreous humour Made of stiff jelly and can change shape to focus lightRetina Clear part that lets light into the eyeAqueous humour Contains light sensitive rod and cone cells

Fovea Transparent jelly that supports the back part of the eyeLens Carries nerve impulses to the brain

Iris Opening in the iris through which light passesBlind spot Watery liquid filling the front part of the eye

Optic nerve Controls the amount of light entering the eyeSclera Part of the retina where the optic nerve enters the eye (no light sensitive

cells)

Pupil Fibres supporting the lens

White Light

Mixture of colors with different frequencies.

When it passes through a prism the colors are bent different amounts by the

glass.

Red, orange, yellow, green, blue, violet.

Dispersion: process of spilling light

Higher frequency waves bend more than those of lower frequency.

Rainbows

Light is dispersed by water droplets Enters water droplets and is refracted according to their wavelengths

Its reflected off the back and refracted when it leaves the drop.

Only one color is observed depending on your line of sight.

A rainbow is always seen directly opposite the sun.


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Science Notes

Scattering of Light

Light from our Sun hits atmosphere the gas particles scatted the blue light as

more particles is scattered through more atmosphere then more light isscattered until it appears red.

Transparent Materials

Some colors may be absorbed and some may be transmitted If color pass through the material, it is colorless

If some pass through and some are absorbed, the material is the color of lightthat passed through

Opaque Objects

Depending on the material some colors are absorbed and some are reflected.

If all colors are reflected: smooth surface will reflect light in a regular way and

will appear silvery (mirror), rough surfaces will scatter light in all directions andthe surface will appear white.

If all colours are absorbed then it will appear black.

It some colours are absorbed and some are reflected, the object will appear tohave a mixture of the colours being reflected.

Optic Fibres and Lasers

Advantages of fibre for telecommunication: ability to carry large amount of data

and for a longer distance

Other uses include for medicine, thin strands for insertion into blood vessels,

lungs etc.

Advantages of optic fibres include: cheaper, thinner, more capacity for

information, wont interfere with other fibres, non-flammable, light weight,

flexible. Lasers are concentrated beams of light of the one colour. They can be used in

medicine (eg eye surgery), in dentistry to remove decay, in cosmetic surgery, incommunications (eg telephones and CD players). In communications they oftentravel through optical fibres.

Lasers: Light Amplification by Stimulated Emission of Radiation.

Laser light travels in the same wavelength and is the same colour

(monochromatic)

They are coherent meaning that each photon follows the same course as

another; its compact and directional with a tight beam.

Uses: tumour, tattoo, hair removal, in optic fibres, DVD and CD, light shows,supermarket scanners, cutting.

Fission and Fusion

Energy from nuclear reactions can be harnessed

Fission: neutrons are fired at uranium causing it to split, releasing neutrons,

radiation and heat. The neutrons collide with each other causing a chain

reaction. Note: the heat can be used for electricity.

Fusion: Occur in hydrogen nuclei are pushed together to form helium nuclei, itreleases a large amount of energy and is the reaction that fuels the sun.

Problems associated with production of radioisotopes: toxic waste is difficult to

store safely, may damage the environment; transportation of waste is a

problem (leakage).


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Science Notes ANSTO irradiates silvers of silicon that are components of computers,

televisions, air-conditioners, cars and video cameras.

CARBON

There are more substances containing carbon than any other carbon

Carbon atoms can link to each other and other elements Simple carbon compounds can join up to form long molecules called

polymers

Hydrocarbons are compounds that contain only carbon and hydrogen

Alcohols

Alcohol has the same structure as a hydrocarbon with one or more of its

hydrogen atoms replaced by a hydroxyl (OH)

Uses of alcohol: drinks, fuels, solvents

Alcohols are soluble in water

An alcohol is an organic compound with the structure of a hydrocarbon exceptone is a OH

Renamed by replacing the e with ol

Good solvents able to dissolve other substances placed in them

Methanol is poisonous. It is used as a solvent and in the making of varnish,

plastics and drugs

Ethanol (C2H5OH) is present in beer, wine and spirits. It is the most common

alcohol. Also used as a solvent and a fuel.

Alcohols burn in oxygen to produce carbon dioxide, water and energy

Ethanol is formed when sugar from fruits is reacts with yeast and bacteria

(fermentation)

Alkanes

Hydrocarbons which contain only single bonds

Alkanes single bond, alkenes double bond, alkynes triple bond

First four alkanes are methane, ethane, propane and butane. Next four are

pentane, hexane, heptane and octane

Burn easily and are valuable as clean fuels

Burn to form water and carbon dioxide when there is oxygen.

Methane + oxygen carbon dioxide + water +energy

Ethane + oxygen carbon dioxide + water +energy

Incomplete combustion when not enough oxygen they burn to produce soot

(black carbon) and carbon monoxide (poisonous)

Petroleum

Consists of both natural gas and rude oil

Made up of many different carbon compounds

Formed by oil and natural gas formed over millions of years from remains of

algae and animals, the remains were buried and covered then heat and

pressure caused the remains to be turned into hydrocarbons

Crude oil is refined by a process called fractional distillation (possible

Complete


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11/25

Science NotesBig Bang TheoryWhat is the BIG BANG THEORY?

The Big Bang Theory is a theory that states:

Most astronomers believe the Universe began in a Big Bang about 14 billion years

ago.

The Big Bang Theory states that the universe exploded in all directions from a single

point called a singularity containing an enormous and concentrated amount ofenergy.

At the instance of creation, the universe must have been very hot with energy being

converted.

In a fraction of a second, the Universe grew from smaller than a single atom tobigger than a galaxy filled with variety of particles at one hundred trillion trilliondegrees and it kept on growing, it is still expanding today.

As the Universe expanded and cooled, energy changed into particles of matter and

antimatter. These two opposite types of particles largely destroyed each other. Butsome matter survived. More stable particles called protons and neutrons started toform when the Universe was one second old.

Over the next three minutes, the temperature dropped below 1 billion degreesCelsius. It was now cool enough for the protons and neutrons to come together,forming hydrogen and helium nuclei (chemical elements).

After 300 000 years, the Universe had cooled to about 3000 degrees. Atomic nuclei

could finally capture electrons to form atoms.

As the universe expanded, radiation took the form of heat, radio waves andmicrowaves

A billion years later, swirling gas clouds compacted to form galaxies, within these

galaxies clouds of gas collapsed to give birth to the first stars made of hydrogenand helium.

What are the major evidences which support the Big Bang theory?

We are reasonably certain that the universe had a beginning. Galaxies appear to be moving away from us at speeds proportional to their

distance. This is called "Hubble's Law," named after Edwin Hubble (1889-1953) who discovered this phenomenon in 1929. This observation supports theexpansion of the universe and suggests that the universe was once compacted.

If the universe was initially very, very hot as the Big Bang suggests, we shouldbe able to find some remnant of this heat. In 1965, Radio astronomers ArnoPenzias and Robert Wilson discovered a 2.725 degree Kelvin Cosmic MicrowaveBackground radiation (CMB) that pervades the observable universe. This isthought to be the remnant, which scientists were looking for. Penzias and

Wilson shared in the 1978 Nobel Prize for Physics for their discovery. Finally, the abundance of the "light elements" Hydrogen and Helium found in

the observable universe are thought to support the Big Bang model of origins.

Epicenter - the point on the Earth's surface directly above the focus of anearthquake.

Focus - refers t the site of an earthquakeRenewable Energy:

These include: tidal power, wave power, solar power, wind power, hydroelectricity,radiant electricity, geothermal power, biomass, compressed natural gas and nuclearpower.Global Warming

Global warming is the term we use for the gradual increase in the averagetemperature at the Earths surface that has occurred over the past century or

so. Why is this happening? First, we need to understand some of the natural

processes that have occurred on Earth for millions of years.

The greenhouse effect is the process whereby greenhouse gases trap some


12/25

Science Notesof the infrared radiation from the Earths surface, which helps moderate the

temperatures at the Earths surface. The natural greenhouse effect has enabled

life to evolve on this planet. Without it, the temperatures experienced on Earth

would be like those on the Moon, which is the same distance from the Sun as we

are far too hot by day and far too cold by night for us to survive. The average

ground temperature on the Moon is 17C. On Earth it is 16C. The difference

arises because the Moon has no atmosphere and hence no greenhouse gases to

help moderate the temperatures at its surface.

What might be the consequences of global warming?

Rising sea levels, mostly from expansion of the upper layers of the seawater, wouldresult in the flooding of low-lying coastal areas. A large number of people would losetheir homes and livelihoods.

There would be damage to marine ecosystems due to the loss of species thatcannot survive in the warmer water.

Much of the polar ice caps would melt, resulting in the loss of specie andcontributing to rising sea levels.

There would be significant changes to climate around the world, including anincrease in the frequency and severity of cyclones, typhoons and other extremeweather events. This may also lead to a wider spread of tropical diseases such asmalaria.

The enhanced greenhouse effect is not the only factor contributing to global warming.The vast amount of heat radiated out by our big cities and big industrial complexesalso contributes to the problem.

Definitions and functions

Current: Electric current measures the amount of charge flowing around the

circuit every second. A large current involves more charge passing through acircuit each second than a small current does.

Voltage: Voltage is a measure of the amount of energy available to push

charges around a circuit and is supplied by batteries, power points and powerpacks.

Resistance: Resistance is a measure of how much an object opposes the

passage of electrons.

Conductor material that allows current to flow easily

Cells batteries, source of electricity

Globe omits light

Switches turns on the flow of electricity

Resistors a device having resistance to the passage of an electric current.

Ammeters instrument that measures current

Voltmeters instrument that measures voltage

ELECTRICITY

Circuits


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Science Notes Current (I) Amps (p)

Voltage (V) volts (v)

Resistance (R) Ohms ()

Conductors are substances hat allow electricity to flow through them easily

(metals & graphite)

Insulators are substances that do not allow electrons to flow through them

easily (plastics, glass, wood)

Current (I) - amount of electrons flowing through a conductor. Ammeter isused to measure current.

Voltage (V) the amount of electrical pressure the power pack gives the

electrons. Voltmeter is used to measure voltage.

Resistance (R) a measure of how hard it is for electrons to flow through aconductor (like water flows through a large smooth pipe more easily thanthrough a narrow, rough sided pipe)

Ohms Law

Ohms law describes the relationship between current (I),resistance (R) and voltage (V)in a circuit.Voltage = current x resistance; V= IR

Parallel Circuit If the globes are arranged next to each other but on separate branches, this is a

parallel circuit.

The voltage used by each globes is the same but current is split between each

branch.

If a globes in this circuit is removed or blows, the other globe will remain lit

Series Circuit

If two or more globes are arranged one after the other

in a line then they said to be in series.

The voltage is split between 2 globes but the current

passing through is the same. Globes will glow dimmer

than a circuit with one globe.

If a globe in this circuit is removed or blows the

circuit is broken so the other globes dont light either.

GENES

V

I R


14/25

Science Notes All living things are made up of cells

Plant and animal cells have 3 parts in common: A cell membrane, cytoplasm and

nucleus

The nucleus contains all the genetic material of an individual, inside the nucleus

theres chromosomes

A gene is a hereditary unit that controls a particular characteristic

Genes determine eye colour, body size, skin type etc.

Each gene is made up of a chemical called deoxyribonucleic acid (DNA)

Genes are located of structures called chromosomes, these are found in the

nucleus.

Humans have 23 pairs of chromosomes, total of 46.

Females have XX chromosomes and males have XYchromosomes

DNA

DNA is the keeper of all our genetic information

Instructions to make a human or animal are contained within molecules of DNA

coiled inside the chromosomes of a cell

DNA is a molecule that contains information our cells require to grow, perform

functions

DNA is found in the nucleus of all cells

A molecule of DNA consists of two strands joined together by cross pieces in a spiral

shape called a double helix.

The rungs of this ladder are chemical units called bases

There are 4 types of bases which are represented by A (adenine), T (thymine), G

(guanine), C (cytosine)

In every base A is always opposite base T and base C is always opposite base G

The sides of the DNA ladder are made up ofsugar and phosphate molecules

Meiosis Meiosis is a type of cell division that takes place in the ovary or testes for

reproduction.

Ovaries produce eggs and testes produce sperm. Lol tadpoles

When a perms meets an egg, the resulting cell will have the correct number of

chromosomes

During meiosis the chromosomes are duplicated once

In the first division, each chromosome of each homologous pair (matching

similar pairs) separates to form two cells. Each cell only has one copy of each kind


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Science Notesof chromosome

In the second division, the duplicated chromosomes separate to produce total of

four daughter cells

Mitosis

A type of cell division that occurs for 3 reasons: growth, maintenance andrepair.

Organized series of steps that result in two daughter cells which are exact copies

of the parent cell

Takes place in all body cells

There is only one division during mitosis

The Human Genome ProjectThe project was an international project to determine the complete genetic code forhumans. It identifies every gene that codes for each characteristic. Findings from theproject:

Genetic code that makes each person unique is 99.9% the same for all people

6% of DNA codes for genes, the rest is junk DNA

Dominant & Recessive inheritance

In each cell there are two genes for each characteristic, each gene can be

dominant or recessive.

A dominant gene over-rites the effect of a recessive gene

Allele is a member of a pair of genes

Homozygous having two identical allele for a single trait

Heterozygous having two different allele for a single trait

A pure bred had identical genes for a particular characteristic

A hybrid had two different genes for a characteristic

Genotype refers to the genes carried by an individual eg. BB, Bb, bb

Phenotype refers to the appearance of the individual eg, brown eyes, blue eyes

etc.

Punnet Square

B B

b Bb

Bb

b Bb

Bb

Mother


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Science Notes

Pedigrees

Pedigrees are simple ways of showing how characteristics are inherited for

several generations.

They are used today to follow a characteristic through generations to discover aninheritance pattern.

Enables us to predict the possibility of producing offspring with genetic diseases.

Mutations

A mutation is any spontaneous change in a gene or chromosome that may

produce an alteration in the related characteristic.

Mutations in normal body cells (not sex cells) affect the organism but will not be

inherited. Only mutations in gametes will be inherited.

Helpful mutations: eg. Granny smith apples and breeders use mutations to

develop new and improved varieties in dogs, cats etc.

IONS/FROM ATOMS TO COMPOUNDS

A charged atom is called an ion

When two elements combine to form an ionic compound the last shell must be

filled

Positive ion is a cation, negative ion is a anion

Ionic bonds occur between metal ions and non-metal ions

Compounds that consist of a positive and negative ion are called ionic

compounds

Dalton:

All matter consisted of tiny particles called atoms which cant be divided into

even smaller parts.

Atoms of the same element were alike and they combined in simple whole

number ratios.

Thomson:

Atoms were positively charged spheres with negatively charged electrons

embedded in them.

Rutherford:

He proposed that atoms had a dense nucleus with positively charged protons

Negatively charged electrons orbited the nucleus.

Bohr:

Electrons orbit the nucleus at different energy levels.

It can move from one level to another by gaining or losing energy.

Precipitation Reactions

Precipitation is the formation of insoluble solid from solution.

All these solutions contain both positive and negatively charged ions.

Sometimes when two solutions are mixed, the positive ions from one solution isso strongly attracted to the negative from the other that a insoluble solid is

formed (precipitate).

Acids and Alkalis

Father Zygotes


17/25

Science NotesAcids:

Liquid state

Corrosive; eat away skin/metals

Weak acids; not corrosive e.g. vinegar

Acid test; turns blue litmus paper red and is 0-6 on the pH scale

Common acids are sulfuric acid (H2SO4), nitric acid (HNO3)

Alkalis:

Aka bases

Turns blue litmus paper pink, turns phenolphthalein (indicator) magenta, 8-14

on the pH scale

Can burn skin

Most are solids but in labs, usually used in aqueous solutions

Common alkalis are sodium hydroxide (NaOH), potassium hydroxide (kOH)

Neutral solutions:

Substances that do not effect the color of litmus paper, 7 on pH scale

E.g. water, sugar solutionpH scale:

Numbers go from 0-14

Acids have a pH number less than 7 and bases have a number greater than

7

You can find the pH of any solution using universal indicator and matching color

change to the pH chart

Atoms

They are the smallest unit of an element.

The atomic number is the number of protons and the number of electrons

The mass number is the number of neutrons and protons. The mass of

electrons is negligible.

Nucleus which contains protons and neutrons

Protons positive charge

Electrons negative charge, found in different energy levels

Neutrons have no charge; neutral

Periodic Table

Elements arranged in order of increasing atomic number

The atomic number equals the amount of electrons, hence no. of protons an

atom has. The atomic mass is the sum of protons and neutrons added together.

The columns are groups and the rows are periods.

The last column of the periodic table are noble gases, they react very rarely and

have full outer shells.

The non-metals extend from boron down to astatine in a zig-zag shape.

Compound: two of more elements chemically bonded together. The rearranging ofatoms, not by the creating of new ones, forms them.Molecules:Two or more same/different non-metals joined together by chemicalbonds.Element: a substance only made up of one type of atomChemical reaction: when reactants combine together chemically to form newproductsSynthesis is when elements combine to form a compound.Decomposition is when a single compound breaks down into its elements or simpler


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Science Notescompounds (eg. Passing an electrical current through water to separate oxygen fromhydrogen)Combustion is when a substance reacts with oxygen to form an oxide and energy isgiven out as heat and light. (Magnesium + oxygen= Magnesium oxide)Corrosion is when a metal reacts with substances such as oxygen, water or othersubstances in its environment

Tests for Gases Hydrogen will make a popping sound when held over a naked flame

Oxygen will relight a glowing splint

Carbon-dioxide turns limewater milky

A physical change is when no new substance is formed. A chemical change is whena new substance is formed. A chemical change involves the rearranging of atoms.

The bond between atoms with full shells is called ionic.

INTELLIGENCE

The human body is multicellular and the cells need to be coordinated.

Define and give examples of the following terms:

The five sense organs, which the body receives information from the external

environment includes: sight (eyes), smell (nose), touch (skin), and hearing (ears),

taste (tongue).

Messages travel from the senses to the brain through nerves.

Stimulus response pathway for the nervous system:

stimulus receptor messenger effector responseStimulus endocrine gland produces a hormone hormone carried around the

body by the blood hormone sensitive tissue respond (heart, blood vessels, liver,sex organs)

Nerve cells with different functions are different shapes.

Each nerve consists of a bundle of nerve cells called neurons

Cells Tissues OrgansDefinitions smallest unit of

living things boundby cell membrane.

groups of cells ofthe same type

groups of differenttissues and cells thatcomplete a specificfunction

Examples Cartilage. heart, liver, etc

EndocrineSystem

It is made up of glands that produce and secret hormones.These hormones regulate metabolism, digestion, blood

pressure and growth.Hormone Chemical messenger made by a gland. It is released into the

bloodstream.Target organ Hormones control the actions of certain cells or organs,

known as target cells/organs.


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Science Notes

Endocrine SystemCommunicationmedium

Bloodstream

Transmission HormonesTime of response Slow

Area effected Response effects many partsof the body

Controlled by PituitaryType of stimulus Usually internal

Nervous impulses travel along the nerve fibres in only one direction.

Movement of information along a nerve is electro-chemical

Reflex arc: nervous pathway where a sensory response travel to the spinal cord

and this initiates a motor action or response without the control of the brain. It

protects the body. Eg. drawing hands away from hot objects, blinking

Receptor A nerve cell that transmits a impulse from a relay nerve cell to an effectoreg. Muscle

Stimulus Information from the environment eg. Light, sound, heat etc.Sensory nerve Action made by an organism after receiving a stimulus

Effector An organ that responds to a stimulus eg. Salivary glandResponse Cells or organs that can detect a stimulus and pass information to a

sensory nerve

Diseases of the endocrine system: Diabetes

Symptoms are glucose in the urine, extreme thirst, hunger and loss of weight

Caused by the body not producing any or enough of the insulin hormone Type 1 diabetes occurs when the body stops making insulin

Type 2 diabetes occurs to those who are overweight and inactive, have high bloodpressure or heart disease

High levels of glucose in the blood cause serious problems

The endocrine and nervous systems work togetherNERVOUS SYSTEM

The major functions of the nervous system in humans are as follows:(i) It keeps us informed about the outside world through the sense organs.(ii) It enables us to remember, think and to reason out.(iii) It controls all voluntary muscular activities like running, speaking etc.(iv) It regulates several involuntary activities such as breathing, beating of theheart, movement of food through the food canal, etc.

Thus, the nervous system makes our body parts work together in proper coordination,as one single integrated unit.

The nervous system is made up of the brain, the spinal cord, and nerves. One of themost important systems in your body, the nervous system is your body's controlsystem. It sends, receives, and processes nerve impulses throughout the body. Thesenerve impulses tell your muscles and organs what to do and how to respond to the

environment. There are three parts of your nervous system that work together: thecentral nervous system, the peripheral nervous system, and the autonomic nervoussystem.

The central nervous system consists of the brain and spinal cord. It sends outnerve impulses and analyzes information from the sense organs, which tell your


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Science Notesbrain about things you see, hear, smell, taste and feel.

The peripheral nervous system includes the nerves that branch off from thebrain and the spinal cord. It carries the nerve impulses from the central nervoussystem to the muscles and glands.

The autonomic nervous system regulates involuntary action, such as heart beatand digestion.

OUR DYNAMIC PLANET

The shape of the continents and fossil evidence suggest that all the continents werejoined together (Pangaea) around 250 million years ago.

The shapes of the continents seem to fit together

Age of Rocks, age is the same on both sides of the continental margin

Similar fossils and rocks are found on different continents

All continents in the southern hemisphere have a flightless bird (Ostrich, Cassowary,

emu, kiwi, (extinct) Moa, rhea and the penguin)

Sea floor spreading on divergent boundaries.

Climate change, fossil evidence shows that vegetation grew on snow-covered

landscapes, suggesting that they were once at a lower latitude Polar Reversal evidence in rocks

The movement of the plate is said to be caused by convection currents in the mantleand to gravitational forces.

This theory states that the lithosphere is made up of twelve rigid plates, which slideover a semi-molten layer of the mantle (Asthenosphere). They interact at their plateboundaries and these results in earthquakes, volcanoes and mountain ranges.

There are three types of plate boundaries:

1. Divergent- move apart2. Convergent- plates collide3. Transform- slide past each other

Tectonic Plate TheoryPlate tectonics is the main current theory in Earth Sciences regarding the developmentof our planet Earth. It is, therefore, appropriate to dedicate some space to explain howthe Earth Science community, step by step, has built this theory, from earlyspeculations, through the gathering of proof and severe debates, up to the refinementand quantification, and still ongoing confrontations with alternative ideas.

What evidence suggests the continents were once joined?

Many fossil comparisons along the edges of continents that look like they fit togethersuggest species similarities that would only make sense if the two continents were

joined together at some point in the past.

Outline the evidence for continental drift and plate tectonicsContinental drift was a theory proposed in 1912 by Alfred Wegener which involvedthe movement of continents. This theory is a part of the concept of plate tectonics.Continents have been drifting for hundreds of millions of years. In the theory of platetectonics the outermost part of the Earths interior is made up of two layers, the outerlithosphere and the inner asthenosphere. Plate tectonic theory arose out of twoseparate geological observations: seafloor spreading and continental drift.

Volcanoes

A volcano erupts when magma escapes from inside the earth. As magma is

escaping from a confined space, a lot of energy is released with it, as happenswith any other explosion. This is why many eruptions also produce hugequantities of gases and dust. Magma sometimes rises under enormous


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Science Notespressure, so it not only finds cracks in the earths crust, it can also create them.When magma reaches the earths surface it is called lava.

Earthquakes

A sudden and violent shaking of the ground, sometimes causing great

destruction, as a result of movements within the earth's crust or volcanic action.The intensity ofearthquakes is expressed by the Richter scale

Tectonic plate movement causes earthquakes. Beneath the surface of the earth

is what is called tectonic plates. These plates, made up of molten lava from themantle and parts of the crust, are constantly moving, converging or diverging.When two plates converge, they are pushing against each other with incrediblestrength. As these two plates push, one might slide over the other. This makesan upheaval of the earth's crust. Tremors are felt on the surface of the earth;depending on the strength, earthquakes can cause significant damage tobuildings, bridges, homes, and roads.

The Mercalli Scale is a measure of the ground shaking from earthquakes.

Impact of Volcanos on the environment

Atmosphere: Poisonous gases are released (Sulphur dioxide, carbon monoxide) Can

cause acid rain. Build-up of ash can lead to a global winter. Lithosphere: New land is formed, volcanic structures and new metamorphic rocks

Hydrosphere: Courses of rivers are changed due to new material, water can be

heated, changing the environment. Dissolved minerals can change pH (acidity)of the water.

Biosphere: Destroy living things (trees), cause of death can be suffocation,

asphyxiation. Bacteria, micro-organisms that live near volcanic vents.

Impact of Earthquakes on the environment

Lithosphere: Rocks break, plates move, fault lines occur, movement of rocks.Folding of rocks,valleys and mountains form. The landscape change

Hydrosphere: Courses of river change due to shift near faults. May cause tsunami ifbeneath the ocean floor.

Biosphere: Trees roots upended, tsunami destroy living things. People are trapped

and buried underneath the rubble. Habitat destruction, food webs, chains andsources disrupted

Alfred Wegner- Explained theory of continental drift with the similarities of rocks, fossils and other

geographical structures.

- Suggested that continents moved sideways as well as up and down.

Tsunami Large ocean wave caused by submarine earthquake that occurred < > 50 km

beneath sea floor

Has a magnitude of less than 6.5 on the Richter scale.

Volcanic eruptions also cause tsunamis.

Faults and FoldsRock layers break and slip under pressure of the earths movement, resulting crack isa fault. Sudden movement is an earthquake.

Normal Fault: pulling apart, fatter piece slides down

Reverse Fault: pushing together, fatter piece moves up

Transform Faults: slide past each other.

More than one faults occur, rift valleys and block mountains can be formed

Compression forces push inward on hot rock causing it to buckle.


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Science Notes

Anticline is a fold where it forms an ant hole like shape. Syncline is a fold where itmakes a bowl like shape. Monocline is a downward slope fold. Over fold is a S shapefold

Fossils Are found in sedimentary rocks

Knowing when an organism lived is important because it helps us place them on theevolutionary family tree

Accurate dates allow us to create sequences of evolutionary change and work outwhen species appeared and became extinct

There are two methods of fating fossils:

Absolute dating

Tells the actual age in years

There are many absolute dating methods e.g. radioactive dating

Nearly all these methods use radio active elements that occur naturally in mineralsRadioactive dating (type of absolute dating)

Uses radioactive isotopes

Useful for igneous and metamorphic rocks which cannot be dated by methods used

for sedimentary

Relies on the fact that certain elements (uranium, carbon, potassium) contain a

number of different isotopes whose half life is exactly known and therefore therelative concentration of these isotopes within a rick or mineral can measure theage

A whole rock or single grain can be dated

Relative dating Can only tell us if something is older or younger than another cannot pinpoint an

actual age in yrs.

Can be applies to fossils found on a particular site and can be used to make

comparisonsStratigraphy

To work out the order the layers were formed in

The oldest rocks and fossils are at the bottom and the youngest at the top

Scientists recognize fossils that have characteristics of various rock layers

They can then place fossils into chronological sequences

These known sequences can be compared with other rocks and fossil form other

sites to provide relative datingCorrelation

Is the matching up of rock columns in different locations to find relative age

Rocks in different areas can be matched up because of the rock and fossil type

Radio telescopes

Many objects in space emit radio signals (stars, sun)

Radio waves travel at the same speed of light waves; 300,000km/s

Radio astronomy is the study of astronomy using radio signals from object in the

universe

There are 8 dishes in NSW (Narrabri, Coonabarabran and Parkes)

Natural selection

Process that results in the alteration of characteristics of a population

Based on the assumption that variation exists in a population

Natural selection selects the most favorable variation while eliminating less


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Science Notesfavorable

Individuals with favorable variation are more likely to survive and reproduce

therefore passing on favorable genes

The characteristics of any population may therefore change overtime to suit itsenvironment, aka Survival of the fittest

Charles Darwin presented his theory of evolution through natural selection in his

book the origin of species (1859).

He visited and kept a journal of his observations whilst travelling from England toSouth America and Australia. During this time, Darwin observed that many speciesthat were clearly related, differed slightly depending on where they were found

Fun Park Physics: Forces A force is a push, pull or twist that causes an object to either increase its speed

(accelerate), decrease its speed (decelerate), change its direction orchange its shape.

Mass is the amount of matter in an object.Types of forces:

Friction acts between any two surfaces that try and slide over one another. Acts in

opposite direction to the movement of attempted movement e.g. slides

Electrostatic force repulsion of like charges or attraction of unlike charges

Magnetic force repulsion of like poles or attraction of unlike poles

Gravity attracts matter to other matter. Every particle in the universe has its own

gravity, the strength depending on mass

Centripetal/centrifugal center seeking force e.g. the rotor

Newtons First Law states two main points:1. An object at rest will stay that way unless a force acts on it2. An object in motion will continue to move in he same direction at the

same speed unless a force acts on it

Inertia is the name for the tendency of an object in motion to remain inmotion or an object at rest to remain at rest, unless acted upon by a force.

Newtons Second Law states:1. Something will happen if a force is applied: the object will accelerate

and he acceleration will depend on the mass of the object.

The force needed to accelerate an object equals the mass of the object multiplied

by its acceleration.

Gives a formula telling us how much force is needed. It takes more force to

accelerate a more massive object. The bigger the force, the bigger the acceleration

If the same force is applies to a big object and little object, thesmaller one will accelerate more

Force = Mass x AccelerationF


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Science NotesF = ma

F stand for force, measured in Newtons (N)

M stands for mass of object in Kg

A stands for acceleration in meters per second (ms^-2)

Matter of balanceThere is usually more than one force acting on any object. Some of these forces maybalance by cancelling each other out. If cancellation is complete then the overall force

is zero.

Newtons Third Law states:1. That for every action there is an equal and opposite reaction. When an

object applies a force to a second object, the second object applies anequal and opposite force to the first.

E.g. When an athlete pushes back and down on the starting block, the starting blockpushes the athlete forwards and upwards.

Machines

Gears Allow for the transfer of movement

Wheels with teeth that lock together with another or connected by a belt/chain

If wheels are the same size then both turn at same speed

Using different sized gears can speed up or slow down movement or

increase/decrease forceLevers

Help lift loads by increasing the original force used

E.g. wheelbarrow, hammers, golf clubs

Three tings in common: fulcrum (pivot), load and forcePulleys

Change the direction of the force making it easier to lift/pull heavy items Reduces amount of force needed to lift

A wheel with rope around it

E.g. raise a flag, escalators

Wedge

Two inclined planes joined together

Used for cutting, splitting or pushing through

Inclined Plane

Sloping flat surface

E.g. a ramp

m a

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