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Transcript of Andrew Newbound © Andrew Newbound 2013. Universe Huge space which contains all of the mater and...
© Andrew Newbound 2013
Science Study Notes 2011
Andrew Newbound
© Andrew Newbound 2013
Universe◦ Huge space which contains all of the mater and
energy in existence Big Bang
◦ Theory that universe started in a big explosion from a single point
Steady state◦ Theory that universe has always existed and matter
is being created all the time Cosmology
◦ Scientific study of theories about history & future of universe
Definitions
© Andrew Newbound 2013
Evidence◦ Something that helps you form a conclusion
Organisms◦ Living things
Darwin◦ Created the theory of evolution and explained it
through the mechanism of natural selection Evolution
◦ Slow change in a population of living things over many generations
Definitions
© Andrew Newbound 2013
Comparative anatomy◦ Study of similarities and differences in body
structures Fossils
◦ Remains/impressions of living things, mostly found in rock
Geographical Isolation◦ Natural arrangements of plants and animals in
particular regions Homo sapiens
◦ Scientific term form modern humans
Definitions
© Andrew Newbound 2013
Lamarck◦ Suggested that evolution was caused by
organisms acquiring variations as they lived their lives, that were then inherited by their offspring.
Natural Selection◦ When only organism best adapted to their
environment will survive and transmit their genes to their offspring
Hominid◦ Early human-like fossils that walked upright on 2
legs and were more like humans than apes
Definitions
© Andrew Newbound 2013
1929
• Edwin Hubble• Red Shift
1933
• Big Bang Theory
1948
• Steady state theory
The Big Bang
© Andrew Newbound 2013
1965
• Robert Wilson & Arno ]]• Discovered microwave radiation in the
universe
1992
• COBE• (Cosmic Background Radiation
Explorer)
The Big Bang
© Andrew Newbound 2013
Astronomer◦ Studies objects in space & info that can be derived
from them Cosmologist
◦ Studies theories about the universe Formation, history & future of universe
Astronomers & Cosmologists◦ Use telescopes + satellites + space probes◦ Computer simulations & models
Big Bang◦ Before = nothing◦ Started space, energy & time
The Big Bang
© Andrew Newbound 2013
Origin of Universe Theory
For Against
Big Bang • Microwave energy detected from Big Bang (background radiation)
• Red shift (universe expanding)
• Ripples in universe
• Starting point
Steady state • Starting point explained
• Galaxies can’t be made of nothing
The Big Bang
© Andrew Newbound 2013
Universe runs out of energy
Stops expanding
Universe shrinks
Back to size of Big Bang
The Big Crunch
© Andrew Newbound 2013
1924
• Aleksanr Oparin• Life originated in pools of water
1953
• Stanley Miller• Showed how earth could have started• Wrong quantities of gases
• Fred Hoyle• Life originated in space• Molecules that make up life – on comets & dust of nebulae
The Beginnings of Life
© Andrew Newbound 2013
1969
• September• Meteorite flashed across sky in Victoria
• 4600 million years old
1997
• ALH84001• Confirmed come from mars• Microscopic patterns similar to bacteria
colonies
The Beginnings of Life
© Andrew Newbound 2013
Bacteria sent into space Spacecraft ‘STARDUST’ collected samples
from Comet Wild 2 in Jan 2004 Evidence for life on earth
◦ Fossils Oldest = bacteria
Use hydrogen sulphide as an energy source
Bacteria in harsh conditions◦ Archaea
The Beginnings of Life
© Andrew Newbound 2013
Planetary scientists◦ Bacteria that can live in other places in the solar
system Mars
◦ Most probable planet to support life◦ Evidence for water has been detected
Best place to find bacterial life◦ Moon surrounding Jupitor/Saturn
The Beginnings of Life
© Andrew Newbound 2013
Born: England 1809 Loved nature studies
◦ Large collection of beetles Sorted them
◦ Catalogued the varieties of pigeons Studied to be a doctor
◦ Left when witnessed a child in surgery Screaming with pain
Charles Darwin
© Andrew Newbound 2013
Heard father & grandfather talk about evolution
Unpaid naturalist on voyage around world◦ Survey parts of world◦ Draw biological specimens + descriptions of them
South America◦ Large fossil bones of extinct animals
Resembled bones in living animals
Charles Darwin
© Andrew Newbound 2013
After earthquake◦ Mussels moved to 3m above high tide mark◦ Showed environments change
Galapagos island finches◦ Each had different:
Shaped beak Source of food
◦ Similar to each other Like once same type of bird
Charles Darwin
© Andrew Newbound 2013
Beetles◦ Small differences between living things are important
Pigeons◦ Living things change over time
Finches◦ Populations change over time and grow apart when
separated Findings
◦ Reluctant to publish◦ Alfred Russel Wallace had same findings◦ Darwin’s theory publicised & well known
Charles Darwin
© Andrew Newbound 2013
Study of similarities & differences in body structures
Similarities◦ Determine evolutionary relationships
Limb adapted by evolution for use in different environments
Comparative Anatomy
© Andrew Newbound 2013
Embryology◦ Study of embryos
All similar during early development
Comparative Embryology
© Andrew Newbound 2013
Comparative anatomy◦ Some bones can be used for different purposes
Pentadacyl limb◦ Bones that are not used may still be around
Comparative embryology◦ Common ancestors changed to form different species◦ Split further along than embryos
Comparative DNA sequencing◦ Measuring how long ago 2 species were 1 species◦ Similarities compared
Humans & chimpanzees 5-6 million years ago (98% similar)
Evidence for Evolution
© Andrew Newbound 2013
Fossils◦ Minerals replaced by carbonates◦ Impressions/casts◦ Chemicals can’t break down
Horse evolution using fossils◦ Come from N. America◦ Had 4 digits per limb◦ Changed to graze tough grasses◦ 3rd digit’s nail = hoof
Evidence for Evolution
© Andrew Newbound 2013
Dating Fossils◦ Position in layers of rock
Law of superposition
◦ Potasium10 Argon40
Older fossils up to 1,000,000 years ago Measure amounts of argon
◦ Carbon14 dating Ratio of carbon14 to carbon12 50,000 years ago
Evidence for Evolution
© Andrew Newbound 2013
Bio-Geographical Distribution◦ Ratites (flightless birds all related)
Emu, Kiwi etc.◦ Continental drift
Evidence for Evolution
© Andrew Newbound 2013
All organisms contain chemicals that are based primarily on carbon
DNA Structural and chemical similarities between
things suggest relationships
Genetic sources
© Andrew Newbound 2013
Study of fossils Evidence of evolution because oldest fossils
are simples animals & plants As rocks get younger the fossils get more
complex
Palaeontology
© Andrew Newbound 2013
Australia has its own distinctive kinds of living things◦ E.g. waratah◦ Endemic to Australia
Explanations◦ Begin as inferences◦ Make hypothesis◦ Produce theories
Best scientific explanation at the time for the available evidence
Geographical Distribution of Related Species
© Andrew Newbound 2013
Carbon Dating = Absolute Dating◦ 1000s of years ago
Relative dating◦ Only tell whether fossil is older or younger◦ Layer of rock found in
Dating Fossils
© Andrew Newbound 2013
Artificial selection◦ Farmers selecting largest/strongest animals for
breeding Slight advantage
◦ More likely to survive◦ Natural selection
Slow◦ Many generations
E.g. Insect resistance to pesticides
Natural Selection
© Andrew Newbound 2013
Use it or lose it Acquired characteristics WRONG
Lamarck's theory
© Andrew Newbound 2013
Survival of the fittest All individuals have different characteristics
(variations) All individuals struggle to survive
◦ Find food, shelter and mates◦ Avoid danger
Some individuals born with variations help to survive◦ Survive best and reproduce to pass successful
variations onto offspring◦ Population changes so that it has characteristics that
make it best suited to the environment
Darwin’s Theory
© Andrew Newbound 2013
Hominids◦ Closer to humans than apes
Pre-hominids◦ Closer to apes than humans
Humans different to other animals◦ Large brain for reasoning & language◦ Opposable thumb
Incomplete fossil records of human evolution
In The Beginning
© Andrew Newbound 2013
Austalopithecus Homo habilis Homo erectus
NeanderthalsCro-Magnon manHomo Sapien
In the Beginning
© Andrew Newbound 2013
Hominid fossil changes◦ Brains grew◦ Face became vertical◦ Brow ridges rose◦ Teeth shrunk
Neanderthals & Cro Magnons◦ Lived in caves
Shelter & protection Preserved from elements
Lots of fossils
Super species◦ Able to destroy all other living things on earth
In The Beginning
© Andrew Newbound 2013
Gripped By Gravity (Motion)
Topic 2
© Andrew Newbound 2013
Mass◦ The amount of matter in something
Weight◦ The force of gravity pulling on a mass
Force◦ A push, pull or twist applied to an object
Acceleration◦ The rate at which an object changes its speed
Net Force◦ The directional sum of all forces acting on an
object
Glossary
© Andrew Newbound 2013
Friction◦ A rubbing force that slows moving objects
Distance◦ How far it is between 2 points
Speed◦ How quickly an object is moving
Time◦ How long it takes between 2 events
Average Speed◦ The total distance travelled divided by the total
time taken
Glossary
© Andrew Newbound 2013
Velocity◦ Speed in a given direction
Ticker timer◦ A device that produces a series of dots on paper
Inertia◦ The tendency of an object to stay still or keep moving
Momentum◦ The product of mass and velocity
Newton’s laws◦ The 3 laws proposed by Sir Isaac Newton that
describe motion
Glossary
© Andrew Newbound 2013
𝑆=𝐷𝑇
Speed Formula
© Andrew Newbound 2013
Distance◦ Measured with tape measure/trundle wheel
Trundle wheel circumference = 1m Time
◦ Measured in seconds (s), minutes (min), hours (h), days and weeks Usually measured in s for experiments
Speed◦ In car, measured in km/h◦ In lab, measured in m/s (
Measuring Motion
© Andrew Newbound 2013
Velocity◦ Important for ships at sea etc.
Instantaneous speed◦ Speed the moment you look at it◦ Measured: Speedometer, laser/radar speed gun
Average Speed◦ Speed if same speed constantly over journey
Average speed velocity, instantaneous velocity◦ Same as speed but with distance also
Measuring Motion
© Andrew Newbound 2013
m/s km/h
Measuring Motion
×3.6
÷3.6
© Andrew Newbound 2013
If go back to start, average velocity is 0
Velocity
© Andrew Newbound 2013
Gradient tells speed◦ Steeper = faster◦ Flat = 0 (object not moving)◦ Straight line = speed not changing
Time along bottom Distance along side Scale must be constant
Distance/time Graphs
© Andrew Newbound 2013
0 20 40 60 80 100 1200
50
100
150
200
250
300
350
400
450
500
Distance/time graph
Time (s)
Dis
tan
ce (
m)
© Andrew Newbound 2013
Easier studied if broken down◦ Measure time taken to walk along segments of path
Constant speed = same distance in same time Ticker timer
◦ Measure time and distance together◦ Hits carbon paper at regular intervals◦ Dots close together = slow speed◦ Dots consistently spaced = consistent speed◦ Moving apart = accelerating◦ Need to know distance & time between dots
Time = 0.02s (◦ 1 dimension (forward & backward)
Measuring Speed
© Andrew Newbound 2013
Use video camera◦ Use pause button on VCR to analyse motion
If picture contains ruler + clock Flashing light
◦ Disco – motion appears jerky Photographed = multiple images of moving dancers
◦ Stroboscopic light Flashes at regular intervals Multiple images of moving object
Multiflash photography Movement in 2 dimensions (up & down, left & right)
Measuring Speed
© Andrew Newbound 2013
Distance from start to finish = cm= m
Number of gaps between dots = number of dots = s Speed = = /
= m/s
Calculating Speed Using Ticker Tape
© Andrew Newbound 2013
Distance from start to finish =9.5 cm=0.095m
Number of gaps between dots =7 number of dots =0.14s Speed = =0.095/0.14
=0.68m/s
Calculating Speed Using Ticker Tape
© Andrew Newbound 2013
Vertical axis = distance Horizontal axis = time Straight line sloping upwards
◦ Motion at a constant speed Horizontal dine
◦ Stationary object w/ no motion Zero speed At rest
Curved line sloping upwards◦ Acceleration
Distance – Time Graphs
© Andrew Newbound 2013
Acceleration
© Andrew Newbound 2013
If a car can go from 0km/h to 60km/h in 6s, what is its acceleration?
Acceleration
© Andrew Newbound 2013
Shows acceleration◦ Slope of graph
Horizontal = constant speed Down = decelerating Up = accelerating
Speed/Time Graphs
© Andrew Newbound 2013
0 120 240 3600
2
4
6
8
10
12
14
16
18
20
Speed/time Graph
Time (s)
Sp
eed
(m
/s)
© Andrew Newbound 2013
Gravity & Acceleration Acceleration
◦ Change in motion over time Circular motion
◦ Changing direction but not speed◦ Still accelerated
Acceleration◦ Increase in speed
Deceleration◦ Decrease in speed
© Andrew Newbound 2013
Jump from aeroplane◦ Keep accelerating until hit terminal velocity
Due to air resistance Car stopping at traffic lights
◦ Decelerates until hits 0 speed Satellite orbiting earth
◦ Constant speed but accelerating due to change in direction
Weightlessness◦ No gravity
E.g. being in space
Gravity & Acceleration
© Andrew Newbound 2013
Jumping = better on moon Running = better on earth Acceleration =
◦ OR
Gravity & Acceleration
© Andrew Newbound 2013
Speed◦ How fast something is moving
Acceleration◦ Going faster, slower or changing direction
Data◦ Information in numerical form
Graph◦ Visual way of displaying data
Ticker timer◦ Leaves dot on a paper tape to record motion
Chapter Review
© Andrew Newbound 2013
Velocity◦ Speed in a given direction
Circular Motion◦ Motion of an object round and round
Harmonic◦ Motion of an object going to and fro
Pendulum◦ Swinging object that can be used to measure time
Weight◦ Downwards force due to gravitational acceleration
Chapter Review
© Andrew Newbound 2013
Gravity affects objects at the same rate◦ Heavy stone, light stone fall at same time
Moon’s gravity < earth’s gravity◦ Can jump higher
Gravity causes objects to accelerate towards earth
Air resistance slows falling objects near earth◦ Terminal velocity
Constant speed◦ Same time to travel same distance
Chapter Review
© Andrew Newbound 2013
Gravity is constant with/without air◦ Objects would fall faster due to no terminal
velocity Higher speed
◦ Shorter time to travel same distance Fall faster & faster if jump from plane
◦ Until hit terminal velocity Average speed
Chapter Review
© Andrew Newbound 2013
Closer together = slower speed
Farther apart = faster speed
Moving apart = accelerating
Moving together = decelerating
Ticker Timer
© Andrew Newbound 2013
Force◦ Push/pull/twist◦ Can change motion, shape of an object◦ Measured in Newtons (N)
Contact force◦ Push/pull/twist through touching an object◦ E.g. hammering a nail, lifting a book
Weight force◦ Movement caused by gravity
Pushes, Pulls and Twists
© Andrew Newbound 2013
Reaction force◦ Pushes against your force◦ Stops you from crashing through the floor
Friction◦ Force that slows movement◦ Pushes against moving objects◦ Ice = low friction surface◦ Need to ride bike
Pushes, Pulls and Twists
© Andrew Newbound 2013
Mass◦ Amount of matter inside an object◦ Measured in kg
Weight◦ Downwards force◦ Depends on your body’s mass + strength of gravity◦ Measured in Newtons (N)
Lift accelerates upward◦ Floor pushes upwards◦ Feet push harder against floor◦ Extra weight
Mass and Weight
© Andrew Newbound 2013
Weightlessness◦ Occurs when there is no gravity
Neutron star = 10 million x mass
Mass and Weight
© Andrew Newbound 2013
Vector◦ Arrow used to draw force◦ Longer = more force
Drawing Forces
© Andrew Newbound 2013
Upwards push of
road
Thrust
Weight
Resistance
forces
1. Law of Inertia
© Andrew Newbound 2013
Newton’s First Law of Motion states that an object will remain at rest, or will not change its speed or direction, unless it is acted upon by an outside, unbalanced force.
Constant speed = balanced forces Seatbelt
◦ Keeps passenger moving with vehicle◦ Prevents law of ineria
1. Law of Inertia
© Andrew Newbound 2013
Newton's Second Law of Motion describes how the mass of an object affects the way that it moves when acted upon by one or more forces.
Larger objects accelerate less rapidly than smaller object acted upon with the same force.
Inertia◦ Property of object that makes them resist change
2.
© Andrew Newbound 2013
Rocket accelerates◦ Loses mass yet has same force
◦ Acceleration is proportionate to force More mass = more inertia
2.
© Andrew Newbound 2013
Net force◦ Sum of forces acting upon it◦ Taking into account their direction
Same side + Different –
Net Force; Resultant Force
© Andrew Newbound 2013
‘For every action there is an equal and opposite reaction.’
OR ‘If one object pushes on another object, then the other object pushes back with equal force.’
Stand on floor◦ Weight force (downwards)=upward force of floor
action reaction Unbalanced
◦ Move in dirrection
Action/Reaction
© Andrew Newbound 2013
Slippery floor◦ Move foot, lower force reaction ∴ slip
Moving in space◦ Cylinders of compressed gas attached to space
suits
Action Reaction
© Andrew Newbound 2013
More momentum = harder to stop
Momentum
© Andrew Newbound 2013
Reducing number of accidents Reducing injuries Seatbelts
◦ Hold occupants in their seas◦ Absorb inertia
Headrest◦ Reduce whiplash from inertia
Crumple zone◦ Crumples to absorb energy
Car Safety
© Andrew Newbound 2013
Air bags◦ Absorb inertia & deceleration forces of occupants
Anti-lock brake systems (ABS)◦ Stop wheels from skidding
Friction lost with road Deep tread
◦ Maximum friction Twice as fast = 4 times longer to stop
Car Safety
© Andrew Newbound 2013
Reaction time◦ Time taken for driver to react to danger◦ Moving from accelerator to the brake
Reaction distance◦ Distance car travels during reaction time
Braking distance◦ Distance taken for car to stop when brakes are
applied Stopping distance
◦ Total distance
Car Safety
© Andrew Newbound 2013
Alcohol & fatigue ◦ Lower concentration◦ Increase reaction
time◦ Stop. Revive.
Survive.
Law 1◦ Seatbelts◦ Headrests
Law 2◦ Airbags◦ Crumple zones
Law 3◦ ABS◦ Tire tread
Car Safety
© Andrew Newbound 2013
2 cars crash at 80km/h◦ = single car crashing into solid barrier
3x speed = 9x stopping distance 4x speed = 16x stopping distance 50km/h accident
◦ Dropped from a 3 storey building 100km/h accident
◦ Dropped from a 12 storey building
Physics Crash Video
© Andrew Newbound 2013
Getting Into GenesTopic 3
© Andrew Newbound 2013
Alleles◦ The alternative forms of each gene
Chromosome◦ A length of DNA, containing many genes
Dominant◦ The one of a pair of opposite characters that
appears when both are inherited Gametes
◦ The sex cells – sperm and ova
Glossary
© Andrew Newbound 2013
Genetics◦ The study of inheritance and variation and the
factors controlling them Genotype
◦ The genetic make-up of an individual Heredity
◦ Passing on characteristics from one generation to the next
Heterozygous◦ Different alleles for a gene
Glossary
© Andrew Newbound 2013
Homozygous◦ 2 of the same alleles for a gene
Meiosis◦ Cell division resulting in daughter cells with half
the chromosome number of the parent cell. (makes the sex cells)
Mendel◦ An Austrian monk who carried out experiments on
pea plants◦ ‘The father of genetics
Glossary
© Andrew Newbound 2013
Mitosis◦ Cell division resulting in in 2 daughter cells each an exact
copy of the parent cell Mutation
◦ Results when a mistake is made in copying of DNA Phenotype
◦ How living things appear and function Recessive
◦ Appearing in offspring only when not masked by a dominant characteristic
Zygote◦ The 1st cell of a new individual, formed when a sperm
fuses with the ova during fertilisation
Glossary
© Andrew Newbound 2013
All living things made of cells/product of cells◦ Cell theory
Unicellular◦ Only have 1 cell◦ E.g. bacteria
Multicellular◦ All familiar plants & animals
Cells & Organisms
© Andrew Newbound 2013
Functions
• Take in substances (assimilate)
• Extract energy from food• Excrete their wastes• Grow• Reproduce• Respond to things
Parts
• Nucleus• Control centre
• Cell membrane• Controls what gets
in/out• Cytoplasm
• Liquid containing various structures (organelles)
Cells
© Andrew Newbound 2013
Additions
• Chloroplasts• Make food
• Cell wall• Strengthens structure
• Vacuoles• Store water & dissolved substances
• Smaller/none in animal cells
Plant Cells
© Andrew Newbound 2013
Cells Tissues OrgansBody
systems
Body System Structure
© Andrew Newbound 2013
All cells = same size◦ Just diff quantity
Cells need body systems◦ Need food, water & oxygen
Delivered by body systems
Cells to Systems
© Andrew Newbound 2013
Plant Cell
cytoplasm
© Andrew Newbound 2013
Microscope
© Andrew Newbound 2013
Eyepiece lens◦ Bends the light to make the object look bigger
Microscope tube◦ Light travels through it to the eyepiece
Coarse focus & fine focus knobs◦ Moves the lens up/down so that the object can be
seen clearly Objective lens
◦ Can be changed so that the object can be magnified more or less
Microscope
© Andrew Newbound 2013
Stage◦ Holds the slide with the object you are looking at
in place Mirror
◦ Makes light bounce through the slide into the lens Base
◦ Holds the microscope up
Microscope
© Andrew Newbound 2013
Cell tissue e.g.◦ Muscle, nerve, skin
Multi-cellular◦ Large groups of cells which specialise
Cell membrane◦ Outside of cell
Cytoplasm◦ Liquid inside cell◦ All except nucleus◦ Semi-transparent◦ Includes cytosol, various organelles
The Cell – How it Works
© Andrew Newbound 2013
Organelles◦ Nucleus = most prominent◦ Mitochondria◦ Cytoskeleton◦ Ribosomes◦ Golgi complex◦ Lysomes
Nucleus◦ Contains DNA & runs the cell
The Cell – How it Works
© Andrew Newbound 2013
Animal
Muscle cell
Muscle
Artery
Circulatory System
Horse
Plant
Epidermal cell
Epidermis
Leaf
Photosynthesis system (leaves & stem)
Whole plant
Cellular Organisation
© Andrew Newbound 2013
Cannot function without food & water Correct temperature
◦ <0°C = cell stops functioning Water freezes
Respiration◦ Burning of food w/ oxygen = energy
What Cells Need to Survive
© Andrew Newbound 2013
Energy is needed for◦ Growth◦ Reproduction◦ Other functions
What Cells Need to Survive
© Andrew Newbound 2013
Nucleus◦ Contains DNA◦ Control centre of cell
Nuclear membrane◦ Surrounds the nucleus◦ Lets in and out RNA
Chemical copy of DNA Used to make protein
Cell membrane◦ Controls entry and exit of chemicals
Cell Organelles
© Andrew Newbound 2013
Protoplasm◦ All contents of cell
Cytoplasm◦ All contents of cell except nucleus
Mitochondria◦ Produces energy from food
Ribosomes◦ Manufactures protein
Endoplasmic reticulum◦ Moves products through the membrane
Cell Organelles
© Andrew Newbound 2013
Chloroplasts◦ Contains chlorophyll
Used for photosynthesis Lysosomes
◦ Stores enzymes Microfilaments/cytoskeleton
◦ Holds organelles in place Vacuoles
◦ Stores food & minerals
Cell Organelles
© Andrew Newbound 2013
Nucleic acids◦ DNA
Deoxyribonucleic acid Stores coded instructions Double helix
Watson and Crick
◦ RNA Ribonucleic acid Allows DNA to read coded instructions
◦ Generally located in nucleus Prokaryote
It is located in an area of the cell Not in a membrane
Nuclear Matter
© Andrew Newbound 2013
Nucleus◦ Control centre
Nucleus=programmed by DNA◦ Instructions
For making all parts of cell Way cell behaves
How carry out functions Transmitting Nerve impulse Supplying energy Contracting (muscle cells) Carrying out photosynthesis
Nuclear Matter
© Andrew Newbound 2013
Nuclear membrane’s pores◦ Connect with endoplasmic reticulum◦ Transport material in and out of nucleus
Nucleus need to be stained to be visible under a microscope
Nuclear Matter
© Andrew Newbound 2013
Shorted and coiled forms of DNA made when the cell is about the divide
Only visible when stained Human cell
◦ 23 pairs◦ 46 individual◦ Sex chromosomes
Information for sexual characteristics◦ Autosomes
Non-sex chromosomes
Nuclear Matter - Chromosomes
© Andrew Newbound 2013
Process of sorting chromosomes into their matched pairs
Important in investigating chromosomal disorders
Karyotyping
© Andrew Newbound 2013
Mitosis
1. Parent cell◦ Chromosomes appear as long thin threads
2. Chromosomes duplicate (chromatid pairs)◦ Become shorter and thicker
3. Chromatid pairs line up◦ Along the equator of the cell
4. Chromatids separate◦ Move to opposite ends of cell◦ Starts to split into 2 cells
5. Daughter cells◦ Chromosomes become longer, thinner and less
distinct
© Andrew Newbound 2013
Homologous Pair◦ Chromosomes exist in pairs in each body cell. One
pair from the mother, one pair from the father Diploid
◦ 2 of each type of chromosome Haploid
◦ Genetes (ova/sperm) contain only 1 of each type of chromosome
Daughter cell◦ Cell that is an exact copy of parent cell due to
MITOSIS
Mitosis
© Andrew Newbound 2013
Occurs in all body parts except sex cells Multicellular organism purpose
◦ Growth and repair Single-celled organism purpose
◦ Reproduction
Mitosis
© Andrew Newbound 2013
Very complex form of cell division Begins same as mitosis Occurs only in reproductive organisms
◦ Ovaries & testes in humans After duplication of chromosomes
◦ From “half-cells” ½ of correct number of chromosomes for organism
Fertilisation◦ Recombine to give correct no. of chromosomes
Meiosis
© Andrew Newbound 2013
Ova23
Sperm23
Zygote
Meiosis
© Andrew Newbound 2013
1. 2 pairs of chromosomes are visible2. Chromosomes double
◦ Joined at centromere
3. Homologous pairs line up along equator4. One of each pair moves to ends of cell5. Chromosomes line up along equator6. Chromosomes separate
+ move to ends of cell7. Membranes form to produce 4 daughter
cells
Meiosis
© Andrew Newbound 2013
Made of many nucleotides◦ Joined like links in a chain◦ Made of sugar – deoxyribose + phosphoric acid
+ nitrogenous base 4 bases
◦ Adenine◦ Thymine◦ Guanine◦ Cytosine◦ Order determines chemical code
Building DNA
© Andrew Newbound 2013
Copied◦ Unzips along bases
RNA◦ Like DNA◦ In every cell◦ Sugar = ribose◦ Base uracil instead of Thymine◦ Used to make copies of DNA
Genome◦ Sequence of bases in the DNA/RNA of a living thing◦ Human = 3100 million base pairs
Building DNA
© Andrew Newbound 2013
Gene◦ Length of DNA◦ Sequence of bases
Code for 1 protein Chromosome
◦ Length of genes DNA
◦ Carries all instructions for cell to function◦ Copied onto carrier molecule
Messenger RNA M-RNA
How DNA Works
© Andrew Newbound 2013
m-RNA◦ Moves out through nuclear membrane
Into cytoplasm of cell◦ At ribosomes
Translated into protein Cells differentiate
◦ As multicellular organisms grow◦ Specialise into different roles & tasks
Stem cells◦ Cells which aren’t specialised◦ Take on any task
How DNA Works
© Andrew Newbound 2013
DNA◦ The material that genes are made of◦ Deoxyribonucleic acid
Gene◦ Coded instructions that control our development
& body function Chromosome
◦ Collections of genes◦ Wound in double helix◦ 23 from each parent
Biotechnology
© Andrew Newbound 2013
Mutation◦ Changes in the code of genes
Biotechnology◦ The exploitation of biological processes for
industrial and other prospects Clone
◦ Any organism with identical genes to their parent organism
Biotechnology
© Andrew Newbound 2013
Completely decode human blueprint Fund laps to map genes of humans
◦ Physical + gene maps Needs 15 years
◦ 3 billion bases in genome
Human Genome Project
© Andrew Newbound 2013
Pros
• Prevent genetic conditions• Testing genes early
on
Cons
• Insurance companies could use info
• Introduction of new genes could make others worse
• Parents may not want to know their condition
Human Genome Project
© Andrew Newbound 2013
Foods derived from genetically modified organisms
E.g. soybean, corn, canola & cotton seed oil
GM Food
© Andrew Newbound 2013
Advantages
• Lower price• Reduces use of toxic
chemicals• Prevents wasted crops• Solve hunger• Grow foods in different
climates• Improve vitamin & mineral
content• Faster growth
Disadvantages
• Lasting effects on other species
• Natural immunity of insects to GM plant changes
• Ownership of food• Allergens
GM Food
© Andrew Newbound 2013
1st mammal cloned from an adult cell◦ 5th July 1996
Produced 6 lambs 2003
◦ Experienced progressive lung disease + severe arthritis
◦ Euthanized Possible cause of short life
◦ Born at age of 6 years◦ Only had 6 left
Dolly – The Cloned Sheep
© Andrew Newbound 2013
Eliminate famine Eliminate STIs Social discrepancy
◦ Only few able to achieve
Cloning
© Andrew Newbound 2013
Born Feb 2 1958 Discovered in 1990
◦ Treatment of cultivating skins from patient= ineffective Requires 14-21 days
◦ Scaring likely to occur Burn wounds taking 21+ days to heal
◦ Scaring less likely to occur <10 days
Dr Fiona Wood AM
© Andrew Newbound 2013
Skin sheets produced in 10 days◦ More could be done
Spray on skin◦ CellSpray◦ Aerosol delivery system◦ Apply cultivated skin to larger burn areas
Treat burns victims quicker◦ Noticeable during Bali Bombings
Dr Fiona Wood AM
© Andrew Newbound 2013
DNA◦ Carries code for making proteins
Form our bodies Made from proteins/products made by proteins
◦ Makes 20 diff amino acids 3 bases code for each amino acid
+ start and stop RNA/m-RNA
◦ Opposite to code for DNA Complementary
Occurs during mitosis
Reading the Code
© Andrew Newbound 2013
Genetic fingerprinting◦ Using someone’s DNA to establish their identity◦ Relies on enzymes
Break DNA into short lengths Separated by Chroma typing
◦ Uses: Forensic work Confirming pedigree of valuable animals Checking genetic diversity of endangered animals
Reading the Code
© Andrew Newbound 2013
Figure thing
© Andrew Newbound 2013
Spontaneous change in gene/chromosome◦ Alteration in related characteristic
Increased rate due to mutagens◦ Mutation-causing agents◦ E.g.
X-rays Gamma rays Ultraviolet light Range of chemicals including benzene
Responsible for genetic variation we see today
Mutations
© Andrew Newbound 2013
Discovered + made detailed investigations of base principals of heredity◦ How traits are inherited
Used pea plants◦ Started w/ pure breeding
Hybrids◦ Plants produced by crossing contrasting breeding
plants
Gregor Mendel
© Andrew Newbound 2013
Dominant characteristic◦ Strong form
Recessive characteristic◦ Weak characteristic
Genes◦ Small factors that controlled inheritance
Alles◦ Diff forms of a gene◦ E.g. purple and white colours in flowers
Gregor Mendel
© Andrew Newbound 2013
Phenotype◦ Appearance of new offspring
Genotype◦ Combination of genes that determine a
phenotype
Gregor Mendel
© Andrew Newbound 2013
P generation (Breeding Parents)
F1 generation(first filial generation)
F2 generation(2nd generation)
Gregor Mendel
© Andrew Newbound 2013
S s
s Ss ss
s Ss ss
Punnett Square
Short hair hybrid dog (Ss) and long haired hybrid dog (ss) with long hair being recessive
© Andrew Newbound 2013
Heterozygous◦ Different alles
Homozygous◦ Same alles
Heterozygous/Homozygous
© Andrew Newbound 2013
23 pairs of chromosomes 100,000 diff genes Linked genes
◦ Lying near each other on the same chromosome Particular characteristic
◦ Determined by 1 dominant/recessive genes Incomplete dominance
◦ Halfway between 2 genes
Human Inheritance
© Andrew Newbound 2013
Females◦ 22 normal pairs of chromosomes
+ XX pair of sex chromosomes Males
◦ 22 normal pairs of chromosomes+ XY pair of sex chromosomes
Sex Determination
© Andrew Newbound 2013
X Y
X XX XY
X XX XY
Sex Determination
Genotype: XX : XY 50% : 50%
Phenotype: Female : Male
© Andrew Newbound 2013
Sex linked◦ Genes found on the X and Y chromosome
Y chromosome only has a few genes compared to the X chromosome
Sex linked genetic diseases◦ Caused by defective genes on X chromosome and
occur more frequently in males than females E.g. colour blindness
Sex Determination
© Andrew Newbound 2013
Females◦ Must contain 2, reate faulty genes to be colour
blind X`X`
◦ 1 faulty gene = carrier Dominant normal gene = proper vision
Males◦ Need only one faulty gene to be colourblind
X`Y
Colour Blindness
© Andrew Newbound 2013
X` Y
X XX` XY
X XX` XY
Colour Blindness
Normal mother and a colour-blind father
Genotype XX`:XY
Phenotype Female MaleCarrier Normal
© Andrew Newbound 2013
X` Y
X` XX` X`Y
X XX` XY
Colour Blindness
Normal mother and a colour-blind father
Genotype XX`:X`X`:XY:X`Y
Carrier Carrier: Colour blind: Normal: colour blind
Phenotype Female:Female:Male:Male
© Andrew Newbound 2013
Chemical ChangesTopic 4
© Andrew Newbound 2013
Chemistry◦ Scientific study of matter, its properties and its
interaction with other matter and energy Model
◦ A representation of something based on a set of assumptions, usually determined through experiments
Charge◦ The net effect of losing or gaining atoms
Spelling List
© Andrew Newbound 2013
Atom◦ The smallest particle of an element
Element◦ A substance made up of only 1 part of an atom
Molecule◦ A group of atoms joined by bonds
Compound◦ A group of different atoms that are joined in a
fixed ratio
Spelling List
© Andrew Newbound 2013
Periodic table◦ The arrangement of elements into a table of
groups and periods Electron shells
◦ The arrangement of electrons around the nucleus, based on energy levels
Chemical formula◦ A shorthand way of writing the name of an
element or compound
Spelling List
© Andrew Newbound 2013
Word equation◦ Shows the changes that occur in a chemical
reaction using words Chemical reaction
◦ Interactions in which atoms exchange or share electrons forming new chemical compounds
Reactant◦ The chemical compounds that combine to start a
chemical reaction Products
◦ The chemical compounds that are produced during a chemical reaction
Spelling List
© Andrew Newbound 2013
All Substances
Pure Substances
Element
Compound
Mixtures
Chemistry Revision
© Andrew Newbound 2013
Element◦ Cannot be broken down into simpler substances◦ E.g. oxygen, argon and helium
Compound◦ Pure substance that can be broken down◦ E.g. sodium chloride◦ Combined elements
Molecule◦ Joined atoms
Chemistry Revision
© Andrew Newbound 2013
Element◦ Not made of anything except self◦ 92 in nature
Many too unstable Can’t look at atoms
◦ Too small◦ Everything we look with is made of atoms◦ Indirect evidence
How it affects what is around it
What are Atoms Made of?
© Andrew Newbound 2013
Proton◦ Define the element◦ Positively charged◦ In nucleus
Neutron◦ No charge◦ Create diff isotopes of element
Electron◦ Negatively charged◦ Orbiting nucleus
What are Atoms Made of?
© Andrew Newbound 2013
Ion◦ Charged atom◦ Different number of protons to electrons
Isotype◦ Atoms of element with different number of
neutrons Nucleus
◦ Makes up 1/10,000 of space in atom Mostly empty space
What are Atoms Made of?
© Andrew Newbound 2013
Rutherford◦ Fired alpha particles at gold leaf
2 protons + 2 neutrons Positive charge
Expected to steer away & he would measure how much they changed direction Actually didn’t change direction very much Many came back at him
What are Atoms Made of?
© Andrew Newbound 2013
Niels Bohr◦ Electrons occupy own orbitals
Colours in emission spectra◦ Represent element giving off light◦ Represents energy level
Outer shell◦ Valance shell◦ Occupied by high energy electrons◦ Predicts properties & reactivity
What are Atoms Made of?
© Andrew Newbound 2013
The Periodic Table◦ Discovered by Mendeleev◦ Patterns appeared periodically◦ Gaps would be filled by elements
Predicted properties
What are Atoms Made of?
© Andrew Newbound 2013
Chemical symbol◦ Unique 1-3 letters◦ E.g. C=carbon, Cl=Chlorine
Atomic number◦ Number of protons in 1 atom of element
Atomic weight◦ Average weight of 1 atom of element◦ Different isotopes◦ Carbon = 12.0107
What are Atoms Made of?
© Andrew Newbound 2013
Group Number of electrons in outer shell (Valence electrons)
Alkali metals 1
Alkali Earth metals 2
Noble gases 8
Halogens 7
What are Atoms Made of?
© Andrew Newbound 2013
Period◦ Row of elements
Number of electrons in shell
What are Atoms Made of?
© Andrew Newbound 2013
Only 1 electron in outer shell
•Very reactive•Can be easily lost•Wants to lose•E.g. Lithium, sodium
Needs 1 electron in outer shell
•Strongly attracts elements to fill shell•E.g. Iodine, bromine, chlorine, fluorine
What are Atoms Made of?
© Andrew Newbound 2013
◦ Sodium donates 1 electron to chlorine Makes stable
◦ Compound Not mixture
Not similar properties to reactants
What are Atoms Made of?
© Andrew Newbound 2013
Ionic Bonding
•1 positive (cation) & 1 negative (anion)
Covalent Bonding
•Share electrons•Not as reactive
What are Atoms Made of?
© Andrew Newbound 2013
~ 400BC◦ Democritus
All substances consist of indestructible particles called atoms
1808◦ John Dalton
All matter consisted of atoms Could not be divided Same element = alike Combined in whole number ratios
Chemical Building Blocks
© Andrew Newbound 2013
1897◦ Sir J.J Thomson◦ Plumb pudding
1911◦ Lord Rutherford
Nuclear model for atom 1913
◦ Niels Bohr Electrons orbit at different energy levels
1932◦ Sir James Chadwick
Discovered neutrons
Chemical Building Blocks
© Andrew Newbound 2013
Protons
• +• In
nucleus
Electrons
• -• Orbit
nucleus• of proton
Neutrons
• Neither +/-
• In nucleus
• About same size as proton
Chemical Building Blocks
© Andrew Newbound 2013
Mass number◦ No. of protons + neutrons
Looking into Atoms
© Andrew Newbound 2013
Shows trends in properties between elements
Predict properties of elements Most elements are solids 2 elements are liquid at room temp (25º)
◦ Some melt just above 11 elements gases at room temp Heaviest natural = uranium
The Periodic Table
© Andrew Newbound 2013
Electrons◦ Determine chemical properties of element◦ Orbit in layers/shells◦ Same number as protons◦ 2 fill 1st shell◦ 8 fill 2nd shell◦ 8 fill 3rd shell (1st 20 elements)◦ 4th shell = partly filled◦ Jump to higher energy level when heated
Electrons and Atoms
© Andrew Newbound 2013
Electron configuration◦ E.g. aluminium = 2.8.3
Electrons and Atoms
© Andrew Newbound 2013
Periodic table◦ Chart showing all elements in order of atomic
number Element
◦ Pure substances made of billions of same type of atom
Compound◦ Pure substance made of billions of same type of
molecule Symbol
◦ Short way of writing chemical name
Chemical Changes
© Andrew Newbound 2013
Formula◦ Way of writing type & ratio of atoms in a compound
Molecule◦ Group of atoms joined in a fixed ratio
Electrolysis◦ Using electricity to cause a chemical change
Decomposition◦ Breakdown of compound into simpler substances
Proton◦ Part of nucleus of atom that determines identity of atom
Electron◦ Orbits nucleus of atom in energy shell
Chemical Changes
© Andrew Newbound 2013
OPTIONAL CONTENT MAY GO
HERE
© Andrew Newbound 2013
Chemical equation ◦ Shows more than word equation◦ Ratios and types of atoms present
Balanced equation◦ Shows even more◦ Atoms only change positions
Not created/destroyed Not shown in chemical equation
◦ Energy changes◦ Rate (speed) of reaction◦ How reactants change into products
Reading Equations
© Andrew Newbound 2013
𝐴𝑐𝑖𝑑+𝑏𝑎𝑠𝑒→𝑠𝑎𝑙𝑡+𝑤𝑎𝑡𝑒𝑟Reactions With Acids
© Andrew Newbound 2013
Salts◦ Ionic compounds
Hydrochloric acid◦ Chloride salts
Sulphuric acid◦ Sulphates
Reactions With Acids
© Andrew Newbound 2013
𝑀𝑒𝑡𝑎𝑙+𝑎𝑐𝑖𝑑→ 𝑠𝑎𝑙𝑡+h𝑦𝑑𝑟𝑜𝑔𝑒𝑛Reactions With Acids
© Andrew Newbound 2013
𝑀𝑒𝑡𝑎𝑙𝑜𝑥𝑖𝑑𝑒+𝑎𝑐𝑖𝑑→𝑠𝑎𝑙𝑡+𝑤𝑎𝑡𝑒𝑟Reactions With Acids
© Andrew Newbound 2013
𝐴𝑐𝑖𝑑𝑠+𝐶𝑎𝑟𝑏𝑜𝑛𝑎𝑡𝑒𝑠→𝑆𝑎𝑙𝑡+𝑊𝑎𝑡𝑒𝑟 +𝐶𝑎𝑟𝑏𝑜𝑛𝐷𝑖𝑜𝑥𝑖𝑑𝑒Carbonates
© Andrew Newbound 2013
Common acids◦ Hydrochloric◦ Sulphuric
Corrosive = harmful◦ Damage/eat away material it touches
Acids & Bases in the Home
© Andrew Newbound 2013
Acid•Sour•Corrosive•Lose hydrogen in water
Base•Bitter•Slippery•Eat away proteins•Lose hydroxide in water
Acids & Bases in the Home
© Andrew Newbound 2013
Indicator◦ Changes colour in different conditions
Acids & bases◦ Litmus
Red = acid Blue = base
◦ Water = neutral Neutralisation reaction
◦ Acid + base
Acids & Bases in the Home
© Andrew Newbound 2013
Acids•Citric acid•Cola drinks•Milk•Shampoo
Bases•Laundry powder•Soap•Dishwashing detergent•Oven cleaners
Acids & Bases in the Home
© Andrew Newbound 2013
Change of chemical partners Cloudy mixture formed
Precipitates
© Andrew Newbound 2013
Soluble•Sodium salts•Potassium salts•Ammonium salts•Most sulfates•Calcium sulfate = slightly soluble
•Sodium carbonates•Potassium carbonate•Ammonium carbonate
Insoluble•Sulfates•Lead•Barium•Most carbonates
Precipitates
© Andrew Newbound 2013
Ionic◦ Type of compound made from attraction of metal
and non-metal ions Covalent
◦ Type of compound made from two non-metals that share electrons
Ion◦ An atom that has lost or gained electrons and now
carries an electrical charge
Chemical Changes
© Andrew Newbound 2013
Lattice◦ Large array of atoms or ions that repeats itself
millions of times Flame test
◦ Where the colours of the flame are used to identify the types of atoms present
Equation◦ A written record of the reactants and products in
a chemical reaction
Chemical Changes
© Andrew Newbound 2013
Limewater◦ Reagent used to test for presence of carbon
dioxide Limestone
◦ Type of rock dissolved away by carbon dioxide gas dissolved in rainwater
Precipitate◦ An insoluble substance that forms when ions
come together Suspension
◦ An insoluble substance shaken in water
Chemical Changes
© Andrew Newbound 2013
Element◦ A pure substance made of only one type of atom
Decomposition◦ When a group of atoms breaks apart into smaller
groups Neutralisation
◦ Reaction where an acid and a base react and destroy each other
Precipitate◦ An insoluble substance made from the reaction of
any two soluble substances
Chemical Changes
© Andrew Newbound 2013
Covalent◦ Groups of compounds formed from atoms of
non-metals Ionic
◦ Groups of compounds formed from metal andnon-metal ions
Compound◦ A pure substance made of 2 or more different
atoms joined in a fixed ratio
Chemical Changes
© Andrew Newbound 2013
Electron◦ The outermost part of an atoms that can be lost
or gained in chemical reactions Calcium carbonate
◦ The chemical compound present in lime, limestone, caves, chalk and cement
Flame test◦ Procedure where atoms are heated and the
colours they produce are recorded
Chemical Changes
© Andrew Newbound 2013
Hydrochloric acid chloride salts Sulfuric acid sulfate salts Nitric acid nitrate salts Phosphoric acid phosphate salts
Chemical Changes
© Andrew Newbound 2013
Combustion (burning)◦ E.g.
Corrosion◦ E.g.
Chemical Reactions
© Andrew Newbound 2013
Acids + metals
◦ E.g.
Acids + carbonates
◦ E.g.
Chemical Reactions
© Andrew Newbound 2013
Neutralisation◦ Acids are neutralised (cancelled) bases
pH 7 (neutral)
◦ E.g.
Chemical Reactions
© Andrew Newbound 2013
Decomposition◦ Single compound is broken down/decomposed
Form 2 products◦ E.g.
Combination◦ 2 elements combining to form a single compound◦ E.g.
Chemical Reactions∆≡h𝑒𝑎𝑡
© Andrew Newbound 2013
Oxygen◦ Glowing split will burst into flames in oxygen
Carbon dioxide◦ Burning splint is put out◦ Limewater turns milky
Hydrogen◦ Pop test
Chemical Reactions - Tests
© Andrew Newbound 2013
Moisture◦ Often visible around top of a test tube when
heating a substance that contains water Nitrogen dioxide
◦ Brown-orange coloured gas
Chemical Reactions
© Andrew Newbound 2013
Waves & EnergyTopic 5
© Andrew Newbound 2013
Waves & radiation◦ Carries energy◦ Formed when particles are pushed from
normal/rest position Springs back to where they were
Pushes on near particles
Sound waves◦ Longitudinal wave motion
Move to and fro in the same & opposite direction to the wave
Move in direction of wave & return to original position Energy is pushed
Waves & Energy
© Andrew Newbound 2013
Compressions◦ Particles move closer together
Rarefactions◦ Spread further apart
Longitudinal waves e.g.◦ Sound waves◦ Explosions◦ Some earthquake waves
Force of explosion◦ Pushes air away
Transferred energy Strong enough to break windows
Waves & Energy
© Andrew Newbound 2013
Water waves◦ Ripples travel outwards◦ Transverse waves
At right angles Transverse waves
◦ Boat over water◦ E.g.
Water Pulse in spring Some earthquake waves
Waves & Energy
© Andrew Newbound 2013
Progressive waves◦ Move energy from one place to another◦ Moving forwards◦ E.g. soundwaves
Standing waves◦ Identical waves in opposite directions◦ E.g. pulse in rubber tube
Travel through substance◦ E.g. water, sound
Don’t need substance to travel through◦ Electromagnetic
Light, radio
Waves & Energy
© Andrew Newbound 2013
Waves & Energy
displacement
© Andrew Newbound 2013
Waves & Energy
rarefaction
© Andrew Newbound 2013
Crest◦ Top of wave
Trough◦ Bottom of wave
Amplitude◦ Distance from normal position to crest/trough
Waves & Energy
© Andrew Newbound 2013
Displacement◦ Distance from crest to trough
Wavelength◦ Length of 1 wave◦ Distance between 2 crests/2 troughs
Frequency◦ Number of waves in a certain time
Waves & Energy
© Andrew Newbound 2013
Vibrating particles◦ Carry the energy in a wave
Atoms◦ Gain energy◦ Absorb it◦ Re-emit it
Travel at m/s◦ Differ in wavelength & frequency
No sharp boundaries between types of waves◦ Overlap
Electromagnetic Waves
© Andrew Newbound 2013
Gamma•Shortest wavelength•Can go through lead and concrete•Medical
X-Rays•Affect photographic film•Medical
Ultraviolet
•Beyond violet•‘Black light’•Cause skin cancer & sunburn•Sunbeds
Types of Electromagnetic Waves
© Andrew Newbound 2013
Light
•Visible light
Infrared•Beside red light•Heat radiation•Passes through some gases and glass•Greenhouses•Trap•Heating
Types of Electromagnetic Waves
© Andrew Newbound 2013
Microwaves
•Telecommunications•Make water molecules in food vibrate
Television & Radio Waves•Longest wavelength•TV & radio signals
Types of Electromagnetic Waves
© Andrew Newbound 2013
Laser Light◦ Surgery
Intense heat Cut away unwanted tissues Burn off skin blemishes
◦ Shopping Read barcodes
Photonics◦ Using light in electric appliances
Waves & Technology
© Andrew Newbound 2013
Satellites◦ cheaper than fixed lines◦ 35880km above the earth◦ Energy comes from solar cells◦ Remote areas
Receive all TV, radio and Internet services
Waves & Technology
© Andrew Newbound 2013
Imaging◦ Being able to see where you cannot normally see
Medical Uses
© Andrew Newbound 2013
Gamma radiation
•Patient given tiny dose of radioactive atoms•Recorded through gamma camera•Different types for diff parts of body
Ultrasound
•Very rapid vibrations•Not detected by our ears•Sound is reflected (echo) off diff parts inside body•Show unborn children, heart function, blood flow, treat kidney stones & gall stones
X-Rays•More absorbed by denser parts of body
Medical Uses
© Andrew Newbound 2013
CAT Scans•CT scans•X-Rays concentrated on small slices•Computerised Axial Tomography•Detector records intensity of X-Rays
Treat Cancer
•Can kill cells•Particularly rapid growth ones
Medical Uses: X-Rays
© Andrew Newbound 2013
Medical Uses: X-Ray ProtectionPlaced close to patient•Not scattered by dust
No-one else in room at
time
Machine placed in room with thick concrete walls•Absorb X-Rays
Entry to X-Ray room is along zig-zag hallway•Stops X-Rays being reflected into busy corridors
Radiation monitoring badges•Thermoluminescent dosimeters (TLDs)•Check radiation levels
© Andrew Newbound 2013
Able to transmit energy◦ Without moving matter
Transverse waves◦ E.g. waves on the surface of water
Compression waves◦ E.g. sound waves
Vibrations◦ Cause sounds◦ Cause compressions & rarefactions
Waves
© Andrew Newbound 2013
Medium◦ Material which waves travel through
Frequency◦ Number of complete waves made in 1 second
Pitch◦ Determined by frequency
Sound◦ Travels faster in solids & liquids than gases
Electromagnetic waves◦ Travel through air at ◦ Can travel through a vacuum
Waves
© Andrew Newbound 2013
Not formed on lakes◦ Not enough space
Size of wave◦ Determined by strength + speed of wave
Diffraction◦ Waves spreading out when they approaches
shallower water Wave hits a cliff/breaks into a beach
◦ Kinetic energy sound + heat energy
Water Waves in the Ocean
© Andrew Newbound 2013
Waver blows over ocean
Energy is transferred from
wind to wave
Water Waves in the Ocean
© Andrew Newbound 2013
Breaking waves◦ Sucks up water to support itself
Not enough since gets shallower Rips
◦ Move straight out◦ Swim sideways if caught in one◦ No waves breaking◦ Used by surfers to get out quicker
Water Waves in the Ocean
© Andrew Newbound 2013
Rays◦ Lines used to show the path of light
Beam◦ Stream of light rays◦ Visible
Particles in substances scatter it Transparent
◦ Most light travels through a substance Translucent
◦ Let just enough light to detect objects on other side◦ Can’t see objects clearly
Riding on a Light Beam
© Andrew Newbound 2013
Opaque◦ Substances which absorb or reflect all light
striking them
Riding on a Light Beam
© Andrew Newbound 2013
Reflections
Convex Mirror(Diverging mirror)
Concave mirror(Converging mirror)
© Andrew Newbound 2013
Angle of incidence= angle of reflection
Reflections
© Andrew Newbound 2013
Image◦ Something that we see that is not really where we
see it Image in curved mirror
◦ Distorted Concave mirror
◦ Enlarged image Convex mirror
◦ Wide view
Mirrors
© Andrew Newbound 2013
Piece of glass/plastic with curved sides Shaped to bend light rays in new directions Shape of lens
◦ Amount of refraction of light◦ Size & type of image
Simple camera lens - convex◦ Focuses light to give sharp image on film
Convex lens at front of eye◦ Focuses light onto cells at the back of our eyes
Using Lenses
© Andrew Newbound 2013
Changes in speed at the boundary◦ Bends towards normal
Refraction of Light
© Andrew Newbound 2013
Rainbow◦ A spectrum of light
Light from sun = separated Dispersion
◦ Separation of light into its colours Filter
◦ Plastic sheet◦ Absorbs some colours but lets others pass
through
Colour
© Andrew Newbound 2013
Tiny particles of dust & water vapour◦ Scatter light
Scatter blue better than red Reflected light from objects
◦ See objects
Colour
© Andrew Newbound 2013
Red Orange Yellow
Green Blue Indigo
Violet
Colour
© Andrew Newbound 2013
Colours of Light
© Andrew Newbound 2013
Natural ResourcesTopic 6
© Andrew Newbound 2013
Allows things to happen & change Cannot be seen Can never be used and destroyed Changes into other types of energy
◦ Most can’t be used again Energy efficiency
◦ Percentage of total energy that is used & not used Joules (J)
◦ Unit of measurement for energy 1000J=1 kilojoule
Energy
© Andrew Newbound 2013
Fossil fuels◦ Non-renewable◦ Will be used up in the future
Non-renewable fuels◦ Cause many environmental problems
Renewable energy sources◦ Can be made again in the environment
Sustainable◦ Can be used in the future without problems:
Economic Environmental Social
Alternative Energy Sources
© Andrew Newbound 2013
Don’t cause pollution Cheap
Readily available
Renewable
Alternative Energy Sources
© Andrew Newbound 2013
Types of Alternative EnergyType Advantages Disadvantages
Hydroelectricity
• More rainwater is replenished in the dam
• Only sometimes suitable
• Disrupts the environment
Tidal energy • Works with environment • Expensive• Only some places are
suitable
Wave energy • Works with the environment
• Cost• Finding locations
Wind energy • Works with the environment
• Small power output per generator
Solar • Amount of suitable sites
Geothermal • Uses unutilised energy • Very limited locations
Biomass • Can make more valuable fuels
© Andrew Newbound 2013
Fuels of the Future
•Fermentation of plant matterEthanol
•Electrolysis of waterHydrogen
•Methane & bacterial decay of animal matterBiomass
© Andrew Newbound 2013
Greenhouse gases◦ Gases which trap some of the energy leaving the
Earth’s surface◦ E.g.
Carbon Dioxide Methane Chlorofluorocarbons (CFCs) Nitrogen oxides
Greenhouse effect◦ Heat from earth radiated towards surface◦ Supports life
Greenhouse Earth
© Andrew Newbound 2013
Enhanced greenhouse effect◦ Burning of fossil fuels more greenhouse gases
Increase in amount of energy trapped in the atmosphere
Rise in temp of atmosphere◦ Clearing forests
For agriculture, paper production
Greenhouse Earth
© Andrew Newbound 2013
Sources of Greenhouse GasesGreenhouse Gases
Main Sources
Carbon dioxide • Burning of coal• Burning of gas• Burning of oil
Methane • Livestock• E.g. cows
• Rice paddies• Mining
CFCs • Aerosols• Refrigerants in fridges and air-cons• Production of plastic foal• Dry cleaning
Nitrous oxides • Fertilisers• Burning of fossil fuels
• Especially petrol
© Andrew Newbound 2013
⇒𝐶𝑎𝑟𝑏𝑜𝑛𝐷𝑖𝑜𝑥𝑖𝑑𝑒+𝑊𝑎𝑡𝑒𝑟Burning Fossil Fuels
© Andrew Newbound 2013
Contained inside nucleus of atoms Fission
◦ Splitting an atom into 2 Protons and neutrons join together at random
Make 2 new atoms Not correct balance between neutrons, protons and
binding energy Eject excess ‘radioactive’
Nuclear Energy
© Andrew Newbound 2013
Radioactive atoms◦ Unstable◦ Decay into stable atoms◦ Excess energy/subatomic particles are ejected
from nucleus Can damage surrounding cells
Fusion◦ Joining atoms of hydrogen to make helium◦ Produces huge amounts of energy◦ No radioactive waste products
Nuclear Energy
© Andrew Newbound 2013
Chain reaction◦ Neutrons being thrown from an atom during
fission triggers more fission Nuclear medicine
◦ Radioactive chemicals to view tumours etc. inside the body
Nuclear radiation can cause tumours◦ Makes cells change
Including DNA
Nuclear Energy
© Andrew Newbound 2013
Chain Reaction
© Andrew Newbound 2013
Fission of a uranium-235 atom produces◦ A krypton atom◦ Barium atom◦ 3 neutrons◦ Gamma rays
Boron can absorb neutrons◦ Used in nuclear power stations
Control rods Change speed of reaction
Power from the nucleus
© Andrew Newbound 2013
Nuclear power station◦ Heat from reaction
Changes water to steam◦ Steam drives turbines◦ Turbines drive generators◦ Generators produce electricity
Power from the Nucleus
© Andrew Newbound 2013
Carbon-14 is radioactive◦ Nucleus is unstable due to extra neutrons
Compared to stable carbon-12
Radioactivity
© Andrew Newbound 2013
•2 protons and 2 neutrons•Like helium nucleus•Shoot out at high speed but slow down in air•Paper and skin can stop them
Alpha Partic
les
Types of Radiation
© Andrew Newbound 2013
•Fast electrons•Neutron breaks up forming a proton and an electron
•Pass through thin sheets of metal•Get through skin•20/30cm in air
Beta Partic
les
Types of Radiation
© Andrew Newbound 2013
•High energy rays•Through thick sheets of metal•Except lead•Can pass deep into our bodies
Gamma rays
Types of Radiation
© Andrew Newbound 2013
Geiger counter◦ Detects radiation
Half-life◦ Time taken for ½ of radioactive atoms in a sample
to decay Carbon dating
◦ Carbon atoms constantly being taken in when alive Including carbon-14
Decay slowly when die Age can be worked out
Radioactivity
© Andrew Newbound 2013
47%
28%
8%
5%
4%
3%3% 2% 1%
OxygenSiliconAluminiumIronCalciumSodiumPotassiumMagnesiumOther elements
Elements in the Earth’s crust
© Andrew Newbound 2013
Resource◦ Useful material/substance obtained from the
Earth Metals
◦ Obtained from minerals called ores Ore
◦ Economically important mineral◦ Useful quantities of a metal◦ Most are impure
Mixed with sand + other worthless materials Gangue
Earth Resources
© Andrew Newbound 2013
Concentrate◦ Concentrated metal ore◦ Carried to smelter
Refined Through heating
Refining◦ Purification of metals◦ Electrolysis
Electrical energy used to deposit pure metal onto large electrodes
Earth Resources
© Andrew Newbound 2013
Froth flotation◦ Method used to extract metals from impure
minerals◦ Make metals stick to kerosene bubbles
Earth Resources
© Andrew Newbound 2013
Stone age◦ People used stone tools and implements
Ancient Egyptians◦ 1st people to smelt copper
Iron Age◦ Began: 1500-1000BC◦ Tech used to extract iron was developed◦ Iron tools were widely used
New Materials
© Andrew Newbound 2013
Industrial Revolution◦ 1750-1800◦ Small workshops factories◦ Hand made machine made◦ Energy
No longer animals + moving water Now steam engines burning coal
Ceramics & plastics◦ Replacing metals in many uses◦ Creating new uses
New Materials
© Andrew Newbound 2013
New materials from biological molecules Ages started at diff times in diff places
◦ Availability of resources was diff New plastics
◦ Kevlar◦ Polycarbonate◦ Terram
New Materials
© Andrew Newbound 2013
• 1500-1000BC
Iron Age
• 3500BC-
Bronze Age
• 5000-2500BC
Copper Age
• 3000-5000 yrs ago
Stone age
New Materials