Science Flashcards
What are the two parts of the nervous system?
Central & peripheral nervous system
What’s the nervous system made up of?
Nerves
What kind of message do the nerves send?
Electric signals
What are the 3 main types of nerve cells?
Sensory, relay, motor
What is the nervous system?
Something the brain can send messages to, to control our body
What’s the order of stimulus response pathway?
Stimulus – Receptor – Control Centre – Effectors – Response
What are examples of effectors?
muscles or glands
What are the parts of nerves?
Cell body, dendrites, axon, myelin sheath
What’s the endocrine system made up of?
Made up of ducts and glands
What’s a hormone?
A chemical messenger which travels in the blood
What are glands?
An organ that produces useful substances that is needed somewhere in the body
What hormone does the pancreas produce?
Insulin & glucagon
What’s homeostasis?
A process to maintain the body temperature when there’s a sudden change in the external environment.
What’s a disorder of the endocrine system and what’s the cause?
Addison’s disease - when adrenal gland doesn’t product enough hormones
What’s a disorder of the nervous system and what’s the cause?
Multiple sclerosis - when immune system mistakenly attacks the brain and nerves
What’s 2 use of kidneys?
Get rid of waste and extra fluids, balance water and salt and remove acids
What are ways to look after kidney?
Don’t smoke, don’t drink, healthy diet, regular exercise
What’s the role of renal dialysis
To help people with kidney failure clean their blood
How does dialysis work?
Blood remove from patient – blood passes through the dialyzer – get all the waste out – blood return to patient
What are the 4 main groups of microorganisms?
Virus, bacteria, protozoan, fungi
What is the difference between infectious and non-infectious diseases?
Infectious diseases spread from person to person, non-infectious diseases can’t spread from person to person, it’s because of everyday habits or was born with it
Define disease:
When there’s something wrong with your body because of microorganisms
Define pathogen:
A harmful microorganism to your body
Examples of the 4 microorganisms:
Virus: covid-19
Bacteria: Salmonella
Protozoan: malaria
Fungi: athlete’s foot
What’s the first and second line defence?
First-line defence - barriers to keep microorganisms out of body
Second line defence – inflammation & get more phagocytes (white blood cells) to engulf foreign particles
What are parts of body that acts as barriers to diseases?
Skin – low hp, doesn’t let microorganisms get into body
Cilia – hair-like projections to get mucous/microbes out of body
Mucous membranes – trap microorganisms
Chemical – tears (enzyme – kill microorganisms)
What is some evidence of the inflammation response?
Swollen – more fluid (blood) in area, more phagocytes (white blood cell) engulf foreign particles, more heat – helps kill pathogen
(Occurs when tissues are damaged)
What’s the role of B-cell
Create antibodies, kill pathogens, remember virus so create antibodies faster next time
What’s active immunity?
Someone’s body creates their own antibodies - lasts for a long time (basically forever), memory cell is produced
What’s passive immunity?
Injections of antibodies, not created by the body - lasts for a short period so have to take multiple injections, no memory cell is produced
What’s vaccine and how does it work?
An injection that contains a weaker/dead version of the virus so your body would create antibodies and memory cells
Which way does transverse transfer?
Transverse waves move particles up and down, energy to the left
Which way does longitudinal waves transfer?
Longitudinal waves move particles left and right, energy moves to the left
Define: Wavelength
The distance between two adjacent crests or throughs on a wave
Define: Frequency
The number of vibrations that pass through a point in a second, measured in Hz
Define: Speed
How fast the wave is going in a direction
Define: Amplitude
The height of the wave
Memorise the wave equation/triangle
Search online
How is sound produced?
By the vibration of matter
(by the vibration of stuff)
Why does sound need a medium to travel?
It cannot travel without a medium as there’re no particles to make the sound wave travel
How are pitch related to frequency for sound wave?
Higher the pitch the higher the frequency, the lower the pitch the lower the frequency.
How are volume related to amplitude for sound wave?
Higher the volume the higher the amplitude, the lower the volume the lower the amplitude
Memories echo equation/triangle
Search online
What are the 7 radiation types on the electromagnetic spectrum?
- Gamma ray
- X-ray
- Ultraviolet
- Visible
- Infrared
- Microwave
- Radio
Identify key trends in frequency and wavelength and relate to energy in the EM spectrum
The shorter the wavelength, the higher the energy and the frequency
What is the law of reflection?
The angle of reflection equals to the angle of incidence (θr = θi)
Memorise concave, convex and plane mirrors
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What is the process of refraction?
The bending of light as it changes direction when it travels from one medium to another
Search online refraction and memorise
OKKKK
What is the absorption of light?
When light is absorbed by matter and converted into energy.
What is the Doppler effect?
The change in frequency of sound or light waves as the source and observer move towards/away from each other
What is an example of the Doppler effect?
The ambulance drive towards ‘me’ the sound would get bigger and there’s an higher frequency but as it starts to move away from me the sound would get deeper and slower
What is the difference between red shift and blue shift?
If something is moving away from us it’s called the red shift. If it is moving closer to us it’s called the blue shift
How can the Doppler effect show that the universe is expanding?
All the stars, planets look a bit red, which means it’s moving further away from Earth. If things are moving further away it’s evidence that the universe is expanding
What are the 4 sphere’s on Earth?
- Biosphere
- Lithosphere
- Hydrosphere
- Atmosphere
Describe the interactions of the Earth’s spheres and how these create and/or influence climate
- Atmosphere currents (wind) drive surface currents in oceans
- Lithosphere shapes ocean and wind movement which affects temperature and rain fall
- Humans (biosphere) cause global warming which affects atmosphere and hydrosphere
- The climate is changed because of the ocean and that’s the hydrosphere
How can volcano eruption effect the Erath’s spheres
- Atmosphere is affected by the ashes that went into the air
- Lava kills plants and animals which affects the biosphere
- Lava would cool and turning into land/rocks which affect the lithosphere
- Affect the hydrosphere as water is polluted by the toxins released
What is the cause of El Nino?
Weakening trade winds, result in warm surface water to the west and less cold water to the east
What is the effect of El Nino?
- Surface water of the Pacific Ocean warm up near Peru
- Water-laden clouds develop, bringing heavy rains in South America
- Often bring drought and dry conditions to eastern Australia and Indonesia
What is the cause of La Nina?
- Equatorial trade winds become stronger, changing ocean surface currents
- Surface of Pacific Ocean near Australia is warm
What is the effect of La Nina?
Water evaporates from the warm ocean and heavy rain clouds develop
What is the word equation for photosynthesis?
Carbon dioxide + water –> glucose + oxygen
Where does photosynthesis occurs?
Photosynthesis is endothermic reaction that occurs in plants
What is the word equation of respiration?
Glucose + oxygen -> carbon dioxide + water
Where does respiration occurs?
In all living things
Memorise carbon cycle
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Why is carbon essential to life?
It is the molecule around which the molecules of life such as proteins, carbohydrates and fats are built
What gases can cause acid rain and where did it come from?
Sulphur dioxide, nitrogen dioxide and they come from burning of fossil fuels or from volcano
How does acid rain occur?
Acid rain forms when sulphur dioxide, nitrogen dioxide are emitted in the air and is transported by wind and air currents
What are the effects of acid rain
Destroys plants, pollutes water sources and soils and erodes buildings
What and where is the ozone layer?
It’s in the atmosphere and it absorbs almost all of the sun’s harmful UV rays, protecting us from skin cancer
What impacts has human activities have on the ozone layer?
Refrigerants and aerosols that has CFCs, HCFCs and VOCs damages the ozone layer
What is the greenhouse effect?
Trapping most of the energy that the sun gives us instead of releasing it back into space to keep us warm
What is the enhanced greenhouse effect?
An increase in greenhouse effect because of human activities
What are some greenhouse gases?
- Carbon dioxide from fossil fuels and deforestation
- Methane from farm animals
- Nitrous oxide from vehicles
What are the impacts of global warming?
Burning fossil fuels, driving cars, flying planes, factories
What is ecosystem?
Where all living things come together with the environment to form life on earth
Give examples and differences of biotic and abiotic components of an ecosystem
Biotic components are all living things such as animals and plants while abiotic components are the non-living things such as water and air
How is matter travelling through food chains/webs?
Producers take the nutrient from the soil and the 1st order consumer takes the energy when they eat the producers…etc then when the consumers died they get decomposed and turn into energy for the producers
Why are decomposers important in ecosystems?
They break apart the dead organisms and turn it into energy for the producers so the cycle can continue
Describe the flow of energy in food chains/webs
Producers get their energy from the sun and/or ground, then 1st order consumer eats and take 10% from the producers, and the 2nd order consumers…etc
Memorise nitrogen cycle
Search online
Why is nitrogen important for plants and animals?
It is the most important part to create protein and other important body materials
What is all matter compose of?
All matter is compose of atoms and has a mass
Describe states and changes of state of matter:
- Solid –> Melting –> Liquid –> Evaporating –> Gas
- Gas –> Condensing –> Liquid –> Freezing –> Solid.
Define: Element
A pure substance made up of only 1 type of atom
Define: Atom
A very small particle that makes up all thing. It can be written as symbols in the period table
What are the metals in the first 20 element?
- Lithium (Li)
- Beryllium (Be)
- Sodium (Na)
- Magnesium (Mg)
- Aluminium (Al)
- Potassium (K)
- Calcium (Ca)
What are the metalloids in the first 20 elements?
- Boron (B)
- Silicon (Si)
What are the non-metals in the first 20 elements?
- Hydrogen (H)
- Helium (He)
- Carbon (C)
- Nitrogen (N)
- Oxygen (O)
- Florine (F)
- Neon (Ne)
- Phosphorus (P)
- Sulphur (S)
- Chlorine (Cl)
- Argon (Ar)
What are the features of a metal?
- Shiny
- Very hard/hard
- Malleable
- Ductile (can be turn into wire)
- Good heat conductor
- Good electricity conductor
- Solids
- Higher density
What are the features of a non-metal?
- Dull
- Brittle (easy to break)
- Non-malleable
- Non-ductile (can’t be turn into wire)
- Bad heat conductor
- Bad electricity conductor
- Solids/liquids/gases
- Lower density
What are the 7 diatomic elements?
- Hydrogen (H2)
- Iodine (I2)
- Nitrogen (N2)
- Oxygen (O2)
- Fluorine (F2)
- Chlorine (Cl2)
- Bromine (Br2)
- CHINFOB !!!!
Define: Compound
More than one type of atoms
Define: Mixtures
More than one type of molecule is present
Define: Chemical changes
A change where new substances are formed. Cannot or hard to reverse.
Define: Physical changes
A change where no new substance is formed. It can be reversed.
What are the factors that affect the speed of reaction?
- Temperature
- Particle size/surface are to volume ratio
- Concentration of reactants
- Stirring
Define: Ionic compounds
Composed of a metal and a non-metal
Define: Covalent compounds
Composed of 2 or more non-metals
What are the formula/scientific name for covalent compounds?
- Mono = 1
- Di = 2
- Tri = 3
- Tetra = 4
- Penta = 5
- Hexa = 6
- Ending must change to ‘ide’
How to write a formula for ionic compound?
- Write the metal first then the non-metal
- Ending in ‘ide’
- DO NOT use prefixes
- Uses valency – drop and swap, then check if valency can be cancelled
How to draw an atom?
- 2 electrons in the 1st shell
- 8 in the others
- Protons = atomic number
- Neutrons = atomic mass – atomic
What is a mole?
6.02 x 10^23
Define: Acid
pH lower than 7
Define: Base
pH higher than 7
What are the properties of acids?
- H+ - hydrogen ions (have H in formula)
- Taste sour
- Corrosion on metal
- Good conductors
- Turns red on litmus paper and universal indicator
- Products metal + SALT + HYDROGEN gas
- Producing salt + water when reacting with base – Neutralisation Reaction
What are the properties of bases?
- Taste bitter and touches soupy
- Corrosive – causes chemical burn
- Good conductor
- Have OH- in formulas
- Turns litmus paper blue
- Turns universal indicator blue or purple
- Producing salt + water when reacting with acid – Neutralisation Reaction
What is the general word equation for the reaction of an acid on a metal?
Metal + Acid –> Salt + Hydrogen gas
What are the ways to increase the rate of reaction between a metal and an acid?
- Higher concentrated acid
- Larger surface area – in small pieces
Define: Neutralisation reactions
Bases balancing out the pH in an acid (turning to neutral)
What are the 3 general word equations for neutralisation reactions?
Metal carbonate + Acid –> Salt + Water + Carbon dioxide
Metal hydroxide + Acid –> Salt + Water
Metal oxide + Acid –> Salt + Water
How to name a salt?
First name of the base + First name of the acid
- Hydrochloric acid + Potassium hydroxide = Potassium chloride
- Sulfuric acid + Calcium oxide = Calcium sulphur
- Nitric acid + Magnesium carbonate = Magnesium nitric
What are 3 examples of fuels?
- Coal
- Wood
- Petrol
What is the general word equation for combustion of a fuel?
Hydrocarbons + Oxygen –> Carbon dioxide + Water
What characteristics does respiration have?
- Controlled
- Happen in cells
- Uses glucose
- Involves food
- Involve enzymes
What characteristics does combustion have?
- Uncontrolled
- Produces light
- Produces sound
What are the similarities between combustion and respiration?
- Chemical reactions
- Both make products
- Uses oxygen
- Release energy
- Release carbon dioxide
- Release water
- Release heat
Define: Exothermic reactions
Release energy
Define: Endothermic reactions
Don’t release energy
