Science Flashcards
1
Q
What are the two parts of the nervous system?
A
Central & peripheral nervous system
2
Q
What’s the nervous system made up of?
A
Nerves
3
Q
What kind of message do the nerves send?
A
Electric signals
4
Q
What are the 3 main types of nerve cells?
A
Sensory, relay, motor
5
Q
What is the nervous system?
A
Something the brain can send messages to, to control our body
6
Q
What’s the order of stimulus response pathway?
A
Stimulus – Receptor – Control Centre – Effectors – Response
7
Q
What are examples of effectors?
A
muscles or glands
8
Q
What are the parts of nerves?
A
Cell body, dendrites, axon, myelin sheath
9
Q
What’s the endocrine system made up of?
A
Made up of ducts and glands
10
Q
What’s a hormone?
A
A chemical messenger which travels in the blood
11
Q
What are glands?
A
An organ that produces useful substances that is needed somewhere in the body
12
Q
What hormone does the pancreas produce?
A
Insulin & glucagon
13
Q
What’s homeostasis?
A
A process to maintain the body temperature when there’s a sudden change in the external environment.
14
Q
What’s a disorder of the endocrine system and what’s the cause?
A
Addison’s disease - when adrenal gland doesn’t product enough hormones
15
Q
What’s a disorder of the nervous system and what’s the cause?
A
Multiple sclerosis - when immune system mistakenly attacks the brain and nerves
16
Q
What’s 2 use of kidneys?
A
Get rid of waste and extra fluids, balance water and salt and remove acids
17
Q
What are ways to look after kidney?
A
Don’t smoke, don’t drink, healthy diet, regular exercise
18
Q
What’s the role of renal dialysis
A
To help people with kidney failure clean their blood
19
Q
How does dialysis work?
A
Blood remove from patient – blood passes through the dialyzer – get all the waste out – blood return to patient
21
Q
What are the 4 main groups of microorganisms?
A
Virus, bacteria, protozoan, fungi
21
Q
What is the difference between infectious and non-infectious diseases?
A
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
22
Q
Define disease:
A
When there’s something wrong with your body because of microorganisms
23
Q
Define pathogen:
A
A harmful microorganism to your body
24
Q
Examples of the 4 microorganisms:
A
Virus: covid-19
Bacteria: Salmonella
Protozoan: malaria
Fungi: athlete’s foot
25
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
26
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)
27
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)
28
What's the role of B-cell
Create antibodies, kill pathogens, remember virus so create antibodies faster next time
29
What's active immunity?
Someone’s body creates their own antibodies - lasts for a long time (basically forever), memory cell is produced
30
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
31
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
32
Which way does transverse transfer?
Transverse waves move particles up and down, energy to the left
33
Which way does longitudinal waves transfer?
Longitudinal waves move particles left and right, energy moves to the left
34
Define: Wavelength
The distance between two adjacent crests or throughs on a wave
35
Define: Frequency
The number of vibrations that pass through a point in a second, measured in Hz
36
Define: Speed
How fast the wave is going in a direction
37
Define: Amplitude
The height of the wave
38
Memorise the wave equation/triangle
Search online
39
How is sound produced?
By the vibration of matter
(by the vibration of stuff)
40
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
41
How are pitch related to frequency for sound wave?
Higher the pitch the higher the frequency, the lower the pitch the lower the frequency.
42
How are volume related to amplitude for sound wave?
Higher the volume the higher the amplitude, the lower the volume the lower the amplitude
43
Memories echo equation/triangle
Search online
44
What are the 7 radiation types on the electromagnetic spectrum?
* Gamma ray
* X-ray
* Ultraviolet
* Visible
* Infrared
* Microwave
* Radio
45
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
46
What is the law of reflection?
The angle of reflection equals to the angle of incidence (θr = θi)
47
Memorise concave, convex and plane mirrors
Search online
48
What is the process of refraction?
The bending of light as it changes direction when it travels from one medium to another
49
Search online refraction and memorise
OKKKK
50
What is the absorption of light?
When light is absorbed by matter and converted into energy.
51
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
52
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
53
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
54
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
55
What are the 4 sphere's on Earth?
1. Biosphere
2. Lithosphere
3. Hydrosphere
4. Atmosphere
56
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
57
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
58
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
59
What is the effect of El Nino?
1. Surface water of the Pacific Ocean warm up near Peru
2. Water-laden clouds develop, bringing heavy rains in South America
3. Often bring drought and dry conditions to eastern Australia and Indonesia
60
What is the cause of La Nina?
1. Equatorial trade winds become stronger, changing ocean surface currents
2. Surface of Pacific Ocean near Australia is warm
61
What is the effect of La Nina?
Water evaporates from the warm ocean and heavy rain clouds develop
62
What is the word equation for photosynthesis?
Carbon dioxide + water --> glucose + oxygen
63
Where does photosynthesis occurs?
Photosynthesis is endothermic reaction that occurs in plants
64
What is the word equation of respiration?
Glucose + oxygen -> carbon dioxide + water
65
Where does respiration occurs?
In all living things
66
Memorise carbon cycle
Search online
67
Why is carbon essential to life?
It is the molecule around which the molecules of life such as proteins, carbohydrates and fats are built
68
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
69
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
70
What are the effects of acid rain
Destroys plants, pollutes water sources and soils and erodes buildings
71
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
72
What impacts has human activities have on the ozone layer?
Refrigerants and aerosols that has CFCs, HCFCs and VOCs damages the ozone layer
73
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
74
What is the enhanced greenhouse effect?
An increase in greenhouse effect because of human activities
75
What are some greenhouse gases?
1. Carbon dioxide from fossil fuels and deforestation
2. Methane from farm animals
3. Nitrous oxide from vehicles
76
What are the impacts of global warming?
Burning fossil fuels, driving cars, flying planes, factories
77
What is ecosystem?
Where all living things come together with the environment to form life on earth
78
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
79
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
80
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
81
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
82
Memorise nitrogen cycle
Search online
83
Why is nitrogen important for plants and animals?
It is the most important part to create protein and other important body materials
84
What is all matter compose of?
All matter is compose of atoms and has a mass
85
Describe states and changes of state of matter:
1. Solid --> Melting --> Liquid --> Evaporating --> Gas
2. Gas --> Condensing --> Liquid --> Freezing --> Solid.
86
Define: Element
A pure substance made up of only 1 type of atom
87
Define: Atom
A very small particle that makes up all thing. It can be written as symbols in the period table
88
What are the metals in the first 20 element?
- Lithium (Li)
- Beryllium (Be)
- Sodium (Na)
- Magnesium (Mg)
- Aluminium (Al)
- Potassium (K)
- Calcium (Ca)
89
What are the metalloids in the first 20 elements?
- Boron (B)
- Silicon (Si)
90
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)
91
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
92
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
93
What are the 7 diatomic elements?
- Hydrogen (H2)
- Iodine (I2)
- Nitrogen (N2)
- Oxygen (O2)
- Fluorine (F2)
- Chlorine (Cl2)
- Bromine (Br2)
- CHINFOB !!!!
94
Define: Compound
More than one type of atoms
95
Define: Mixtures
More than one type of molecule is present
96
Define: Chemical changes
A change where new substances are formed. Cannot or hard to reverse.
97
Define: Physical changes
A change where no new substance is formed. It can be reversed.
98
What are the factors that affect the speed of reaction?
- Temperature
- Particle size/surface are to volume ratio
- Concentration of reactants
- Stirring
99
Define: Ionic compounds
Composed of a metal and a non-metal
100
Define: Covalent compounds
Composed of 2 or more non-metals
101
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’
102
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
103
How to draw an atom?
- 2 electrons in the 1st shell
- 8 in the others
- Protons = atomic number
- Neutrons = atomic mass – atomic
104
What is a mole?
6.02 x 10^23
105
Define: Acid
pH lower than 7
106
Define: Base
pH higher than 7
107
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
108
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
109
What is the general word equation for the reaction of an acid on a metal?
Metal + Acid --> Salt + Hydrogen gas
110
What are the ways to increase the rate of reaction between a metal and an acid?
1. Higher concentrated acid
2. Larger surface area – in small pieces
111
Define: Neutralisation reactions
Bases balancing out the pH in an acid (turning to neutral)
112
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
113
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
114
What are 3 examples of fuels?
- Coal
- Wood
- Petrol
115
What is the general word equation for combustion of a fuel?
Hydrocarbons + Oxygen --> Carbon dioxide + Water
116
What characteristics does respiration have?
- Controlled
- Happen in cells
- Uses glucose
- Involves food
- Involve enzymes
117
What characteristics does combustion have?
- Uncontrolled
- Produces light
- Produces sound
118
What are the similarities between combustion and respiration?
- Chemical reactions
- Both make products
- Uses oxygen
- Release energy
- Release carbon dioxide
- Release water
- Release heat
119
Define: Exothermic reactions
Release energy
120
Define: Endothermic reactions
Don't release energy
