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science notes 2021

Unit 8.1 ecosystems
What is an ecosystem?
An ecosystem is a grouping of organisms that interact with each other and there environments.
Three major principles of ecosystem
1. Nutrient cycling (i.e., carbon cycle, water cycle and nitrogen cycle):
Movement of chemical elements from the environment into living organisms and
from them back into the environment through organisms live, grow, die and
Energy flow (producers and consumers):
– Energy is required to transform inorganic nutrients into organic tissues of an
– Energy is the driving force to the work of ecosystem.
Relationships (i.e. predation)
– It refers to the particular pattern of inter-relationships that exists
between organisms in an ecosystem.
Factors influencing organisms
Biotic factors: These are living factors such as predators, parasites, fungi,
infectious organisms, competitors for food and shelter and collaborations.
Abiotic factors: These are non-living factors such as air quality and humidity,
the amount of sunlight, rainfall, wind, tides, waves, lightning and fires.
Abiotic factors are also known as physical factors.
The main abiotic factors in an ecosystem:
Oxygen Levels
Soil Type
Main Biotic factors in an ecosystem:
animals, plants, trees, grass, bacteria, moss, or molds
The main abiotic factors in an ecosystem
Symbiosis: Symbiosis is any type of a close and long-term biological interaction between
two different biological organisms, be it mutualistic, commensalistic, or parasitic.
Competition: Competition is an interaction between organisms or species in which both
the organisms are harmed.
Predation: Predation is a biological interaction where one organism, the predator, kills
and eats another organism, its prey.
Mutualism: Mutualism describes the ecological interaction between two or more species
where each species has a net benefit.
Commensalism: Commensalism is a long-term biological interaction in which members of
one species gain benefits while those of the other species neither benefit nor are
Environmental changes and populations
The abiotic & biotic factors of an ecosystem can change over both short & long period of
time, i.e. the amount of sunlight available over 24 hours & over the 4 seasons.
Changes in abiotic factors affect the biotic factors,
These changing factors lead to changes in rates of birth, death, immigration and emigration
which then lead to changes in population size.
Emigration: Emigration means an animal leaves its home because the habitat is
no longer ideal for them
Immigration: Immigration means an animal establishes a home in a habitat
because it has resources it can utilize or because the habitat is ideal for them
What is interdependence?
All organisms in an ecosystem depend upon each other. If the population of one
organism rises or falls, then this can affect the rest of the ecosystem.
In order for plants to grow they need light water minerals and space
Why can introduced species become a problem?
Invasive species are capable of causing extinctions of native plants and animals,
reducing biodiversity, competing with native organisms for limited resources, and altering
What is global warming?
Global warming is a gradual increase in the earth's temperature generally due to the
greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants
Unit 8.2 sustainability
Food chains and food webs
All food chains begin with green plants called producers, all other organisms are called
Food chain
Energy is transferred from one organism to another in the direction of the arrow.
All food chains begin with producers; all other organisms are called consumers.
Producer  herbivores  carnivores  omnivores  decomposers
Producer  1st order consumer  2nd order consumer  3rd order consumer 
Be able to identify the effect of changes in a food chain
o e.g. an increase in 1st order consumers can lead to a decrease in the number of
o e.g. an increase in producers can lead to an increase in the number of consumers
Consumers – feeding types
Herbivores  eat producers/plants
Carnivores  eat other consumers/animals
Omnivores  eat other consumers and producers. They eat animals and plants.
Ranking consumers
producers  make their own food
primary consumer OR 1st order consumer  eat producers
secondary consumer OR 2nd order consumer  eat primary consumer
tertiary consumer OR 3rd order consumer  eat secondary consumer
4th order consumer  eat 3rd order consumers
decomposers  organism that decomposes, or breaks down
Food Web – Be able to construct food chains from a food web
Importance of producers
They can capture the suns energy and take carbon dioxide out of our atmosphere and
produce oxygen
The producers are the foundation of any ecosystem and are critical to the survival of an
entire ecosystem.
They create the matter, or biomass, that sustains the rest of the ecosystem.
Importance of decomposers
Without the decomposition of matter, nutrients cannot be recycled for new plants
(producers) to use.
1. Producer- the organisms that act as the source of food in every community
2. Consumer- organisms that must consume other organisms to obtain energy
3. first order consumer- a herbivore (plant eating animal)
4. second order consumer- animals that feed on herbivores
5. third order consumer- an animal that feeds on the second order consumers
6. Herbivore- an animal that feeds on plants
7. Carnivore- an animal that feeds on other animals
The nitrogen cycle
Nitrogen is an element that is found in all living organisms, mainly in the protein as well as in
some lipids and vitamin.
How does the nitrogen cycle work?
1. Nitrogen-fixing bacteria absorb nitrogen gas from the air in the soil and make it into
ammonia (NH3). This process is called nitrogen fixation
2. Nitrifying bacteria then convert the ammonia into nitrites then nitrates. This process is called
3. Nitrates are absorbed by plants through the roots and is used to construct protein and other
4. Animals that consume the plant takes in the nitrogen from the plant.
5. Some nitrates that are not absorbed by the plants can be turned back into atmospheric
nitrogen by denitrifying bacteria. This process is called denitrification.
Lightning can also turn atmospheric nitrogen directly into nitrates.
Nitrification: Nitrification is the process by which ammonium (NH4+) or ammonia (NH3) is
oxidized into nitrite (NO2-) and nitrates (NO3-).
Nitrifying bacteria: bacteria that convert ammonia to nitrates in the soil.
Nitrogen fixing bacteria: bacteria that convert nitrogen gas into nitrates in the soil or root
Denitrifying bacteria: bacteria that convert nitrates (NO3-)into nitrogen gas (N2).
Denitrification: This is the reverse process of nitrification. During denitrification nitrates are
reduced to nitrites and then to nitrogen gas and ammonia.
Energy flows in ecosystems
Energy does not cycle through an ecosystem like matter does
Energy flows from one organism to another when being consumed
The amount of energy decreases as we move up the food chain. That is, only 10%
of the original energy that enters the food chain gets passed on from one trophic
level (number of steps it is from the start of the food chain) to the
Most energy is lost in the form of heat which is produced during
various metabolic processes in the body e.g. growth, repair of tissues,
excretion, reproduction, breathing, etc.
Biomass: the amount off living mass in a habitat
The purpose of obtaining energy
Animals eat because they need energy to carry out all the actions and chemical reactions
necessary to survive.
They save some extra energy as chemical energy (i.e. fat for animals or starch for plants) for
the future only.
Unit 8.3 human impacts on the
Habitat destruction
3. What’s the ecological impact of this?
The habitat has been destroyed and some animals have declined in numbers.
Introduced species
Introduced species are animals and plants that have been brought into Australia from a
different country.
1. Why do introduced species usually cause a problem?
Some of these animals are predators that kill native animals. Some just compete with the
native species for food, while others destroy habitat.
Unit 9.1 moving continents
Continental drift
Alfred Wegener proposed the theory of continental drift. He described that the
continents were all once joined to form one supercontinent (Pangaea)
3 main evidences that lead to the theory:
1. Continents can fit together like a jigsaw puzzle
2. Fossils of ancient animals across many continents
3. Identical rocks and mountain structures have been found on either side of the
Rifts: cracks
Seafloor spreading: The process of new crust forming at the ocean ridges and spreading
Ocean trench: a deep channel in the ocean floor where crust is sinking downwards
Subduction: when one plate sinks below another plate during a collision
Magnetic striping: patterns of strips of rocks with alternating magnetism.
Seafloor spreading
Who proposed the theory?
Harry Hess
What is seafloor spreading?
Seafloor spreading is a process that occurs at mid-ocean ridges, where a divergent boundary
is causing two plates to move away from one another resulting in spreading of the sea floor.
As the plates move apart, new material wells up and cools onto the edge of the plates
Evidence that support his theory:
magnetic striping – two sides of the ocean ridge have identical positioning of the
magnetite particles and width
-the process of the Earth’s magnetic poles changing places is called the magnetic
age of the sea floor – older rocks are further from the ridges
sediment thickness – sediment layer becomes thicker as you move away from the
Support for harry Hesse’s theory of seafloor spreading
Evidence 1: Magnetic Striping
- Definition:
patterns of magnetism trapped in rocks on each side of plate boundaries
- Why did this happen?
The magnetite particles will align themselves with the Earth’s magnetic field when they are still
Once the molten lava solidifies, the magnetite particles are locked into positions
Evidence 2: age of the seafloor
Dating of the rocks shows:
1. The further the rocks are from the ridges, the older they are.
2. Seafloor rocks (200 million years old) are much younger than the continental rocks
(thousands of millions of years old).
The further the rocks are from the ridges, the older they are
Evidence 3: sediment thickness
The sediment layer becomes thicker as you move away from the ridges.
This supports the idea of seafloor spreading as it would require a longer time for the
sediments to be accumulating on top of the seafloor.
The sediment layer becomes thicker as you move away from the ridges
Ocean trenches and subduction
Hess proposed that the crust was sinking down into Earth, forming ocean trenches.
Ocean trench is a deep channel in the ocean floor where crust is sinking downwards.
The process of the crust sinking down and tectonic plates crashing into each
other is called subduction
At subduction zones, the edge of the denser plate subducts, or slides, beneath
the less-dense one.
The denser material then melts back into the Earth's mantle.
Tectonic plates and earths layers
Convection current theory
The semi-liquid asthenosphere layer forms convection current and
as the crusts sit right on top of it, the frictions drag the plates along
with them.
Convection currents are the result of differential heating. Lighter
(less dense), warm material rises while heavier (more dense) cool
material sinks.
It is this movement that creates circulation patterns known as convection currents in the
atmosphere, in water, and in the mantle of Earth.
Gravity theory
Slab Pull: The plates at the subduction zone is denser and is
therefore pulled downwards more by the gravity at the subduction
Ridge push: as new rocks are forming at the ridges, they are higher
above the seafloor than other areas, therefore gravity pulls it
downwards, pushing the old rocks to the sides.
Unit 9.2 plate movement
Continental crust: the crust that forms the continents
Oceanic crust: the crust that forms the ocean floor
Converging boundaries: where plates are colliding with each other
Diverging boundaries: where plates are moving away from each other in opposite directions
Transform boundaries: where plates are sliding parallel to each other but in opposite directions
GPS ground station: a receiver and computer that can detect satellite signals and calculate positions
on earths surface
Island arc: a chain of islands formed at the edges of colliding tectonic plates where one plate
Type of
movement and
crust formation
Rifting, or
spreading apart of
oceanic or
continental plates
creates new crust
East African
Convergent: Subduction of
faster moving plate
and oceanic destroy crust
volcanic island
deep ocean
Convergent: Subduction of
Continental denser oceanic
and oceanic plate destroys crust
mountain ranges
along coast
deep ocean
Plates are the same
density, so
mountain ranges
are pushed
Mountains in
mountain ranges
No characteristic
San Andreas
Fault in
crust not created
nor destroyed
plates slide laterally
beside each other;
crust not created
not destroyed
types of crust
continental crust  less dense, lighter and thicker
Oceanic crust  denser, darker and thinner
Types of plate movement
Diverging boundary
Converging boundary
Transform boundary
types of crusts:
Type of
Diverging (constructive)
Converging (destructive)
Moving apart from each
Colliding with each other
Sliding past each other
When oceanic plate converges with continental plate, the sub- ducting plate is oceanic plate
which is denser.
Some activity that might occur at a subduction zone is trench and volcanos.
Oceanic and oceanic or continental plates can collide.
When two oceanic plates collide, the faster-moving plate subducts.
A resulting feature of a collision zone is converging boundary.
Unit 9.3 volcanoes and earthquakes
Earthquake: the rapid movement of the ground, usually back and forth and up and down in a wave
motion, due to the movement of tectonic plates
Epicentre: the point on earths surface directly above the focus of an earthquake
Focus: the place below ground where an earthquake starts
Hot spots: isolated places away from plate boundaries where a lot of hot magma is collecting
Lava: molten rock that has erupted onto earths surface
Magma: molten rock below earths surface
Primary waves (p-waves): a longitudinal seismic wave that travels fast through earth.
Secondary wave (seismic waves): a transverse t\seismic wave that travels though earth
Seismic wave: the shaking wave like movement of the ground in an earthquake
Seismometer: an instrument that detects the seismic wave from an earthquake
Surface wave: a seismic wave that travels along the surface of the earth in the crust
Tsunami: a huge wave in the ocean caused by an earthquake on the seafloor
Volcano: a place where really hot material from inside the earth erupts at the surface
What is a volcano?
A volcano is a place where extremely hot material from inside Earth erupts at Earth’s
surface. This material include:
 gas such as steam and hydrogen sulfide (SH2)
 Ash (fine particles of rock)
 Lava (molten rock)
 Lumps of solid volcanic rock such as scoria
Volcanoes and plate boundaries
Most volcanoes are at or near the edges of tectonic plates.
This is because the movement of the plates creates weaknesses in the crust and also
generates intense heat that can melt rock.
Plate boundaries
Diverging plate boundaries create weaknesses in the crust because separating plates thin
the crust.
Converging plate boundaries also create weaknesses in the crust and generate a lot of heat
which causes the rocks to melt more.
The molten magma beneath is easier to find its way up through the weakness in the crust.
Hot spot volcanoes
While most volcanoes form near plate boundaries, some form well away from the edges of
the plates, this is known as hot spots.
Hot spots: isolated places away from plate boundaries where a lot of hot magma is
They can occur under oceanic or continental plates.
spot volcanoes and chains of islands
In the ocean, hot spot volcanoes occur in chains of islands.
In each chain, there is always one island with an active volcano, while all the other islands
have dormant (inactive) volcanoes.
Hot spot volcanoes and the theory of plate tectonics
As the plate moved, the island went with it and so the island no longer sat over the hot spot.
A new part of the plate was now above the hot spot, and this gradually formed a new
Detecting earthquakes
Earthquakes are measured using an instrument called a seismometer.
The trace of a seismometer is called a seismograph.
Seismic waves
The waves in Earth caused by earthquakes are called seismic waves.
Three main types of seismic waves can be detected:
Surface waves
Longitudinal waves
Transverse waves
Neither longitudinal nor transverse waves
(circular wave)
Travel fast through
Travel slightly slower than Pwaves
Travel the slowest
Cause the most destruction
Primary waves (P-waves)
Secondary waves (S-waves)
surface waves
Epicentre and focus point
Earthquakes usually happens along a fault, where Earth slips.
The place where the quake starts is called its focus
The point on Earth’s surface directly above the focus is called the
Buildings near the epicenter are usually most heavily damaged
Unit 7.1 they make us sick!
Disease: anything that causes your body to stop working properly.
Contagious: very easy to spread, used to describe a disease.
Infectious disease: a disease that can be spread
Pathogen: an organism that causes disease (disease causing agent)
Bacteria: microscopic, single-celled organisms
Pathogenic bacteria: bacteria that cause disease
Quarantine: isolation to prevent the spread of a disease
Antibiotic: a substance that kills bacteria or prevents the growth of bacteria
Penicillin: an early antibiotic
Vaccine: a chemical that causes your body to react as if it had encountered a pathogen
Infectious vs. non-infectious diseases
Immune system
Definition of immune system: The body’s defence against disease causing agents (pathogens) and
foreign particles.
Three lines of defences
First Line of Defence
The surface barriers that prevent pathogens from entering the body
Chemical/physical barriers
Second Line of Defence
Role of fever
Reduce the growth rate of pathogens
Destroy pathogens that cannot survive in extreme heat
Role of inflammation
To increase the amount of blood (carrying white blood cells) reaching an infected area.
1. Damaged or infected cells release a histamine (a chemical)
2. Histamine causes more blood to flow to the infected area, resulting in swelling and
3. The temperature of the area around the injury increases, suppressing bacterial growth
4. Attracted by chemical alarm signals, white blood cells move from the blood into the injured
area through the walls of the swollen, leaky capillaries.
5. White blood cells, such as neutrophils and macrophages, attack invading pathogens and
consume dead and infected cells.
Role of macrophages
Macrophage is a type of white blood cell of the immune system that engulfs pathogens and
destroys them via enzymes.
White blood cells (WBCs) normally circulate throughout the blood, but will enter the body’s
tissues if invaders are detected
Third Line of Defence
Most infections never make it past the first and second lines of defence
Those that do are targeted according to their type by other types of WBCs.
This is called a specific immune response.
1. When macrophages engulf a pathogen and break them up, they present fragments of
identification markers on their surfaces (antigen).
2. Macrophages then show these fragments to T-cells, who identify the pieces and tell B-cells to
make antibodies.
3. Antibody is a chemical made by the immune system that makes it easier for white blood
cells to destroy pathogens.
Once infection is dealt with, memory T and B cells remain in the body, so that the 3rd line can
be activated straight away next time.
Antibiotics fight bacterial infections either by killing bacteria or slowing and suspending its
Using antibiotics can lead to ‘superbug’ because bacteria can develop resistance.
Alex Fleming discovered antibiotics. He observed a mold formation, and no bacteria was
around it. He came to the conclusion that mould killed the bacteria.
Vaccines are chemicals that cause your body to react as if it had met a pathogen.
Case study – smallpox
o Developed by Edward Jenner
He took material from a blister of someone infected with cowpox and inoculated a
13-year-old-boy with vaccinia virus (cowpox), and demonstrated immunity to
This infestation would not be acceptable today because subjecting child a deadly
virus is unethical
Stomach ulcers
A stomach ulcer occurs when the lining of the stomach gets damaged and the gastric juice
causes pain at the damaged area. The stomach normally produces acid when it comes in
contact with this area, then this causes pain.
Immunity and immunization
What is the difference between active and passive immunity?
What is gastroenteritis.
Gastroenteritis is a short-term illness triggered by the infection and inflammation of the
digestive system.
Stomach pains-stomach ulcers
What is a stomach ulcer?
A stomach ulcer occurs when the lining of the stomach gets damaged and the gastric juice causes
pain at the damaged area. The stomach normally produces acid when it comes in contact with this
area, then this causes pain
What was previously believed to be the reason for stomach ulcers?
It was previously believed that stress, poor diet, alcohol, smoking or too much caffeine cause the
Why was the scientific community skeptical?
Because they didn’t believe that a bacterium could survive in the acidic environment in the stomach
How this discovery helped patients get relief.
This discovery of the cause of the stomach ulcers had made it now curable.
Unit 7.2 other sources of infection
Fungicide: a chemical that kills fungi
Host: the organism the parasite lives in
Host cell: a cell invaded by viruses
Spore: a single cell, used by fungi to spread
Virus: a pathogen about 100 times smaller than a bacterium
Viruses and host cells
Viruses are pathogens that are about 100 times smaller than bacteria.
Viruses can only grow and reproduce inside cells they have invaded – host cells.
A virus uses the host cell to make thousands copies of itself.
What is the difference between a cold and the flu
Flu and the common cold are both respiratory illnesses, but they are caused by different
Two types of illnesses have similar symptoms, but flu develops more quickly and can be
more severe.
Infection with the flu virus causes a high temperature, and your whole body aches. However,
your nose will not run as much as it would with a cold.
How is the cold and the flu spread?
Close contact with an infectious person (including in the 48 hours before they had
Ccontact with droplets from an infected person’s cough or sneeze
By touching your mouth, nose or eyes with fingers that picked up the virus from a surface or
object touched by someone who is sick.
What can I do to prevent getting sick?
Avoiding exposure to sick people
Washing your hands frequently
Covering your mouth when you cough or sneeze
Why doesn’t the doctor give me antibiotics?
Antibiotics are used to treat bacterial infections. They do not kill the viruses that cause colds
and flu.
Antibiotics would only be required if the flu has led to a secondary bacterial infection.
Childhood diseases-measles
Measles is a highly contagious, serious disease caused by a virus.
Signs and symptoms
Fist sign  High fever
Initial stage  Runny nose, coughing, red and watery eyes
After several days  Rash
Coughing and sneezing, close personal contact or direct contact with infected nasal
or throat secretions
The chickenpox virus causes a runny nose and a slight fever, followed by a rash of small, very
itchy blisters.
Scratching the blister can lead to permanent scarring or to secondary bacterial infections of
the blister.
After a person has been infected, the chickenpox virus can remain inactive in the nerve cells
of the body for many years.
An outbreak is a rise in disease cases over what is normally expected in a small and specific
location generally over a short period of time.
Epidemics are essentially outbreaks without the tight geographical restrictions.
A pandemic is an epidemic that spreads across many countries and many continents around
the world.
The normal circulation of a virus in a specified location over time describes an endemic
Parasitic diseases
A parasite is an organ is that lives on or in the body of another organism (the host) and takes
nutrients from it.
Malaria is an infection caused by a parasitic protozoan organism called Plasmodium.
Mosquitoes can carry the Plasmodium from one host to another.
In Australia, complete eradication was declared in 1981.
Travellers sometimes bring malaria back into northern Australia.
Wear protective clothing
Use insect repellent
Use a mosquito net when sleeping
Empty any standing water where mosquitoes could breed.
Amoebic dysentery
Amoebic dysentery is an intestinal infection caused by a protozoan parasite.
Mode of transmission  Spread through contaminated water
 drink boiled water or sealed, bottled water.
 don’t eat fruit or vegetables that may have been rinsed in tap water and not
Fungi disperse (spread) by spores.
The spores just need to find a warm, moist environment and they will start to grow.
Fungal infections are contagious.
Mode of transmission  skin-to-skin contact, the sharing of towels, or walking on floors that
an infected person has walked on.
Unit 7.3 non-infectious diseases
Asbestosis: a lung disease caused by breathing in asbestos fibers
Caffeine: a stimulant drug that acts on the brain
Carbohydrates: nutrients used as the main source of energy for the body
Chronic disease: a disease that lasts for a long time
Diabetes: a complex disease caused by a lack or insensitivity to insulin.
Diabetic: the person who has the disease diabetes
Fats: nutrients used as a source of energy, and an energy store in the body
Heart attack: when part of the heart muscle is damaged or dies because the blood supply is blocked
or severely reduced
High blood pressure: when the blood pressure in the arteries remains high between heart beats and
during rest.
Insulin: the hormone that lowers the level of glucose in the blood
Kwashiorkor: a disease caused by a lack of protein
Malnutrition: when the nutrition of the diet does not meet the needs of the body.
Minerals: nutrients required for various functions in the body
Nutrients: protein, fats, vitamins, carbohydrates and minerals
Nutrition: the food necessary for health and growth
Over-nutrition: a form of malnutrition in which the body is receiving more nutrients then required
Protein: nutrients used for growth and repair of the body
Rickets: a disease caused by a lack of vitamin d
Scurvy: a disease caused by a lack of vitamin c
Stroke: when the part of the brain is damaged or dies because the blood supply is blocked or
severely reduced
Type one diabetes: a type of diabetes in which the body stops producing insulin
Type two diabetes: a type of diabetes in which the body has become resistant to insulin
Under-nutrition: a form of malnutrition in which the body is not getting enough of the required
Vitamins: nutrients that control many functions in the body
We all need nutritional diets
Nutrients are substances essential for healthy growth and maintenance of our body.
Water is also essential in our diets
Nutrients we need:
 Protein
 Carbohydrate
 Fats
 Minerals
 Vitamins
 Iron- part of haemoglobin in red blood cells.
 Calcium and phosphorous- form strong teeth and bones
 Sodium and potassium- balance water content in your body
 Sodium- needed by your nerves and muscles (including your heart) to work properly.
Protein is used for growth and repair.
Comes from meat, fish, and dairy
Main source of energy
Grains such as wheats and oats contain starches and sugars.
Fruit and vegetables also contain carbohydrates.
Provides twice as much energy as carbohydrates
Body stores energy as fat
Fats are found in oils, meat and dairy products
Do not provide energy
Important for your health
 Iron- part of haemoglobin in red blood cells.
 Calcium and phosphorous- form strong teeth and bones
 Sodium and potassium- balance water content in your body
 Sodium- needed by your nerves and muscles (including your heart) to work properly.
Are only required in small amounts
Control many of the chemical reactions in the body.
Provides no energy or nutrition
Essential for health
More than 60% of our body is water
Chemical reactions of metabolism takes place in the watery environment of your cells
Water in the blood carries nutrients around the body.
Healthy diet
Disease can also occur when people:
don’t eat enough
Eat too much
Eat the wrong things
The Australian government has produced a guide to healthy eating.
This guides what we should eat and how much to eat in a healthy diet.
The guide classifies foods into 5 groups:
• bread, cereals, rice, pasta, noodles
• vegetables
• fruit
• milk, yoghurt, cheese
• meat, fish, poultry, eggs, nuts, legumes.
Food should be eaten from each group every day, however not in equal quantities.
Malnutrition- occurs when diet does not provide the nutrition the body needs (undernutrition)
Affects energy levels, development and normal growth
1. Kwashiorkor (kwa·shee·aw·kaw)
Caused by a lack of dietary proteins
Affects muscle and brain development
Pot belly caused by weakness in the stomach muscles and build up of fluid (oedema)
2. Scurvy
Caused by a lack of vitamin C
Symptoms include:
- Swollen & sore joints
- Teeth falling out, bleeding gums
- wounds heal slower
3. Rickets
Caused by a lack of vitamin D and calcium in children
Bones remain soft and legs bend outwards when babies begin to walk
Overweight & obesity:
Consuming more energy than the body needs will be stored as fat under the skin and around
the organs
Decrease in exercise and activity due to screens.
Leads to unhealthy increase in weight  overweight  obesity
Too much salt:
Salt is important in our diets for regulating water in our body.
Too much salt e.g., from processed food, can lead to kidney failure and is linked to high
blood pressure
High blood pressure:
The heart pumps blood into arteries it is under high pressure, but pressure decreases
between pumps.
High blood pressure is when the pressure in the arteries remain high between heartbeats
and at rest.
 Strains artery walls
 Causes fats to stick to artery walls
 Can lead to heart attack and stroke
Stimulant/ drug
Found in coffee, tea, chocolate, energy drinks, cola
May cause:
 Increase breathing and heartrate
 Restlessness
 Dizziness
 Headaches
 Sleep problems
Glucose vs. insulin
What happens when we eat?
1. Digestion of our food produces glucose
2. Glucose moves from our gut into the blood
3. The hormone insulin moves the glucose from the blood and into our cells.
4. In the cell, glucose is broken down via cellular respiration.
5. This process releases energy
6. The energy is used by muscles and other cells for growth, repair and other essential
Type one diabetes
Early onset
Not related to lifestyle, may be genetic
Body stops making insulin
Causes under-nourishment because energy can’t be released from their food
10-15% of diabetics are type 1
Regularly test blood glucose levels
Inject with insulin
Type two diabetes:
Late onset
Related to lifestyle, may be genetic
Body becomes resistant to insulin
Even though body produces insulin, it cannot use it
Blood glucose levels always high so they gain weight easily.
85-90% of diabetics are type 2.
Environmental disease:
Naturally occurring minerals and human made chemicals can be harmful to our health.
E.g. asbestos- naturally occurring mineral
Asbestos miners and other exposed to asbestos have:
Cough, shortness of breath and blue lips.
Asbestosis is a lung disease caused by breathing in asbestos.
Can cause mesothelioma (cancer) 30-40 years after exposure.
In 2003 all asbestos use was banned in Australia.
Well done, trucker
Trucken finished