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MODULE 1: ANSWER SCHEME
PAGE 44
ANSWER SCHEME MODULE
SCIENCE SPM MODULE REMEDIAL
MODULE 1
TOPIC 2: BODY COORDINATIONTHINGS TO REMEMBER :1. (i)Relay neurone
(ii)Sensory neurone (iii)Motor neurone
(iv)Proprioceptors2. (i) cerebrum
(ii)cerebellum
(iii) medulla oblongata
(iv)spinal cordEXERCISES
1.A
2.C3.A
4.C5.A
6.B7.C
8.C9.D
10.DMODULE 2
TOPIC 2: BODY COORDINATION1. (a) X: cerebrum
Y: cerebellum
(b) Controls involuntary action/ any examples of involuntary action
(c) To store more information
// More space for neurones
(d) Become blind // Cannot see
2. (a) P: Pituitary gland
Q: Thyroid gland
(b) (i) insulin/glucagons
(ii) Insulin:
Converts excess glucose to glycogen
Glucagon:
Converts glucagons into glucose
(c) Suffers diabetes mellitus
// Sugar level cannot be controlled
MODULE 3
TOPIC 2: BODY COORDINATIONExercises1.D
2.C
3.B
4.C
5.B
6.B
7.C
8.D
9.A
10.AMODULE 4
TOPIC : HEREDITYQ1
Q2 (a) dominant, recessive
(b) monohybrid
(c) phenotype
(d) genotype
(e) Mendel
Q31.
2.
3.
4.
5.
Q4(a)46
(b)46
(c)sperm
(d)ovum
(e)44 + XY
(f)44 + XX
(g)22+X and 22+Y
(h)22 + X
Q5
(a) ( X )
(b) ( / )
(c) ( X )
(d) ( / )
(e) ( / )
(f) ( X )
(g) ( / )
(h) ( / )
(i) ( X )
(j) ( X )Q6
1. A
2. A
3. C
4. C
5. C
MODULE 5
TOPIC : VARIATION1 (a)
Height of students (cm)
146-150151-155156-160161-165166-170
Number of students
181993
(b)
Number of student
height/cm
2 (a) Continuous variation
(b) Weight, skin colour
3 (a)
CharacteristicsNumber of students
Attached ear lobe
12
Free ear lobe
8
(b)
number of students
type of ear lobe
(b) Discontinuous variation.
(c) genetic
Q4
1. Continuous variation
Height, body weight, intelligence, skin colour, length of fingers, length of sole.
2. Discontinuous variation
blood group, ability to roll the tongue, left-handedness, types ear lobe, presence of dimples, types of fingerprint.
3. Importance of variationVariation enable individuals of the same species to be distinguishable.
MARKING SCHEME MODULE 6
TOPIC : MATTER AND SUBSTANCE
6.1 Atomic StructureA
1. proton / neutron / electron2. proton and neutron
3. electronBSubatomic
particlesprotonneutronelectron
Symbolpne
Charge
+10-1
Relative mass
111/ 1840
Location
In the nucleus
In the nucleus
In the electronShells around the
nucleus
6.2 Proton Number, Nucleon Number and IsotopesA.Proton number
Same number of proton but different number of neutrons
Isotopes
Total number of protons and neutrons
Nucleon numberNucleon number proton number
Neutron numberNumber of protons
B.ElementNumber of protonsNumber of electronsNumber of neutronsProton numberNucleon number
J
3343
3 +4 = 7
K
777714
L
9
9
10919
M
111112
1123
N
1313141327
C.1. Q and SD.1. B 2. A
MODULE 7
TOPIC : MATTER AND SUBSTANCE
A.WORD PUZZLE
B. THINK AND COPY
C. Objective Questions
1.D
2.A
3.C
D. Relation Between Changes in Heat with Changes in Kinetic Energy of the Particles
in Matter Relation Between Changes in Heat with Changes in Kinetic Energy of the
Particles in Matter
ABSORBS HEAT / ENERGY
RELEASES HEAT / ENERGY
ABSORBS HEAT / ENERGY
RELEASES HEAT / ENERGY
E. Objective Questions
1.C
2.D
3.B
MODULE 8
TOPIC : MATTER AND SUBSTANCES
1.
GROUP
lllllllVVVlVllVlll
Period 112
Period 2345678910
Period 31112131415161718
Period 41920
Period 5Transition Elements
Period
6
2. B
3. A
4. B
5.
(a)
( i )P / Q / R
( ii )T
( iii )S
(b)
( i )P / Q
( ii )Q
( iii )T
( c) P and Q
( d)
P3
S5
T18
6)
a) In order of increasing proton number
b)
( i )D and F
( ii )E
( iii )A / B
( i v )F
c) From Metal -------- Semimetal --------- Non - metal
d) D
e) D / E / F
MODULE 9
TOPIC : ENERGY AND CHEMICAL CHANGES PHYSICAL AND CHEMICAL
CHANGES
Complete the table:
Physical changesChemical changes
SIMILARITIESSubstances undergo changes
DIFFERENCES
YesNew substances formedNone
YesChange in chemical compositionNo
NoChanges are reversibleYes
YesPhysical changesNo
A lotEnergy requiredVery little
1
ExampleType of changes
(a)Firewood burningChemical change
(b)Tin can rustingChemical change
(c)Butter meltingPhysical change
(d)Using chalk to write on boardPhysical change
(e)Baking breadChemical change
(f)Drying clothesPhysical change
Objective Questions
Question NoAnswerQuestion NoAnswer
2A6D
3A7A
4B8D
5B9D
10A
MODULE 10
TOPIC: ENERGY AND CHEMICAL CHANGES HEAT CHANGES IN CHEMICAL
REACTIONS
Objective questions
Question NoAnswersQuestion
NoAnswers
1A5B
2A6B
3D7D
4A
Structured questions
1(a)Solution
Thermometer reading / 0C
Distilled water
.35..
Distilled water + Ammonium chloride crystals28..
(b)Ammonium chloride crystals dissolved in distilled water will increase .
the thermometer reading because heat is released(c)(i)constant variable : Volume of distilled water
(ii)manipulated variable: Presence of ammonium chloride
crystals(iii) responding variable : Thermometer reading
(d)Endothermic reaction is a reaction which cause a decrease/ drop / fall
of temperature reading 2(a)(i)Experiment A: 210C
(ii) Experiment B : 430C(b) (i)constant variable : volume of distilled water/
initial temperature reading
(ii)manipulated variable:type of substances
(iii) responding variable : final temperature reading
(c)
Hydrochloric acidAmmonium sulphateCalcium hydroxide crystals
((
MODULE 11
TOPIC : ENERGY AND CHEMICAL CHANGES-REACTIVITY SERIES OF METALS
1(a)(i)MetalObservation
Sodium
Volume of gas released more//
5 bubbles gas is released
CalciumVolume of gas released is less//
3 bubbles gas is released
(ii)Sodium (metal) is more reactive than calcium (metal)
(b)(i)constant : volume of water// mass of metal
(ii)manipulated: type of metal
2(a)(i)X : hydrogen
(ii) Use a burning wooden splinter. Pop sound is heard
(b)(i)turns blue
(ii) Is alkaline (solution)
(c)Calcium + water
+ 3(a)(i)Hydrogen
(ii) Pop sound is heard
(b) Zinc oxide
(c)Zinc + steam
+
MODULE 12
TOPIC: NUCLEAR ENERGY Exercise Question numberAnswer
1C
2C
3D
4A
5B
6D
7B
8D
9B
10. (a) R = Beta radiation
S = Gamma radiation
T = Alpha radiation
(b) (i) (a) Alpha / T
(b) Beta / R
(ii) Alpha radiation carries positives charges, causing it to be attracted
towards the negative plate.
Beta radiation carries negatives charges, causing it to be attracted towards
the positive plate.
(c) Gamma radiation are neutral as they carry no charge.
(d) (i) Beta
(ii) Alpha
(e) Gamma
(f) Store the radioactive source in thick-walled containers made from lead.
11. (a) i. alpha
ii. beta
iii. gamma
(b) Gamma, beta, alpha radiation.
(c) (i) Gamma
(ii) Can penetrate through our body
(d) Gamma ray
(e) Store the radioactive source in thick walled containers made from lead .
12. Alpha Radiation Positive charge
Low penetrating power
A sheet of paper
Beta RadiationNegative charge
High penetrating power
AluminiumGamma Radiation Neutral
Higher penetrating power
Block by a block of lead
MODULE 13TOPIC: LIGHT1.
2.
3.
a)Object distance
b)Image distance
c)Thickness of the lens4.
a) i) Object at infinity
ii) Characteristics of image formedi) real
ii) Inverted
iii) Diminished
iii) Image distance
formed at F (opposite side)b)i) Object distance
Beyond 2F
ii) Characteristics of image formedi) Real
ii) Inverted
iii) Diminished
iii) Image distance
Between F and 2F (opposite side)
c) i) Object distance
At 2F
ii) Characteristics of image formedi) Real
ii) Inverted
iii) Same size as object
iii) Image distance
At 2F (opposite side)d) i) Object distance
Between 2F and F
ii) Characteristics of image formedi) Real
ii) Inverted
iii) Magnified
iii) Image distance
Beyond 2F (opposite side)
e) (i) Object distance
Between optical centre and F
ii) Characteristics of image formedi) Virtual
ii) Upright
iii) Magnified
iii) Image distance
On the same of object but farther awayf) Concave lens
Characteristics of image formedi) Virtual
ii) Upright
iii) DiminishedMODULE 14TOPIC: LIGHT
1.
2.
i) Redii) Blueiii) Green3.
i) Magentaii) Cyaniii) Yellow4.
a)
b)
c)
5.
a)
b)
c)
6.
7.
MODULE 15TOPIC: LIGHT1 and 2 .
3.i and ii
4.
5.
SIMILARITY
CAMERAEYE
Use convex lensUse convex lens
Image formed is real, inverted and diminishedImage formed is real, inverted and diminished
Amount of light entering the camera is controlled by controlling the size of aperture. This is done by diaphragm.Amount of light entering the eye is controlled by controlling the size of pupil. This is done by the iris.
DIFFERENCES
CAMERAEYE
Lens made of glassLens is made of gel
Focusing is done by changing the position of lens; lens moves further away from film for the near objects and moves towards the film for distant object.Focusing done by the ciliarys muscles change the shape of the lens; thicker lens for near objects and thinner lens for distant objects
Focal length of the lens is fixed.Focal length of the lens varied
Image formed on film is permanent.Image formed on retina is only temporary.
6.
MARKING SCHEME MODULE 16TOPIC: CHEMICALS IN INDUSTRY
A.AlloyCompositionUses
Steel
Iron + carbonConstruction building, bridges and machine
Pewter
Tin +
( antimony & copper)
Making household articles / decorative item / tableware / teapots /plates / spoons / *
Bronze
copper + tin Making art objects such as statues, cups, medals
and knives
Brass
Copper + zincMaking musical instruments and food container
DuraluminAluminium + copper +
Magnesium + ManganeseMaking aircrafts / boats / bicycle / *
( * Accept any possible answer)
B.
1. Alloy
2. Superconductors
3. a) Substance B
b) Substance B
c) Substance B
d) because added metal has atoms of different size / atoms stops the rows from
sliding each other.
e) bronze, brass, steel
f) bronze / duralumin
A.
Nitric acid / Fertilisers / Nylon production / Explosives / Refrigerants / Pharmaceuticals / Household cleaners.
B.a) Coolerb) 1 : 3
c) Iron catalyst
d) Temperature- 4500 C / Pressure -200 atm
e) Sulphuric acid
C.Ammoniasolution+Nitric acidAmmonium Nitrate +Water
Ammoniasolution
+Sulphuric
AcidAmmonium Sulphate+Water
Ammoniasolution
+Phosphoric
AcidAmmonium phosphate+Water
Ammonia
+Carbon
Dioxide Urea
D.
1 C
2 C
3 B
4 AMODULE 17
TOPIC: MICROORGANISM AND THEIR EFFECTS ON LIVING THINGSIMPORTANT POINTS
1. X : Alga Y : Protozoa
CharacteristicsVirusesBacteriaProtozoaAlgaeFungi
ShapeRod,cubic,
spherical
Spherical,
Spiral,rod,
vibrioRound,
Spherical,
spindleRound,
Filamentous,
colonialSpherical,
Filaments
Size0.5 m
or smallest0.2 -10 m5 - 250m
1 - 1000 m10 -100 m
NutritionParasite
Autotrophic
Saprophyte / ParasiteAutotrophic/
Parasitic,Make their own foodSaprophyte / Parasite
HabitatLiving cells
Air,water,soil
Food,living
organism,
decaying matterinside bodies of living things,sea,fresh water,damp soilFresh water,sea water,damp soil, barks of treesDecaying organisms matter,outside/inside living organisms
Method of rerroductionUsing materials
In living cellsBinary fission,
conjugationBinary fission,
conjugationBinary fission,spore formation,
conjugationBudding,spores,
conjugation
2.3. light, temperature, humidity
5.
Pathogens
(Microorganisms that cause disease)Diseases
BacteriaCholera, tuberculosis,diphtheria,gonorrhoea,
syphilis
VirusesInfluenza,dengue fever,hepatitis A &B,poliomyelitis
ProtozoaDysentery,malaria,sleeping sickness
FungiRingworm,athletes foot,oral thrush
6. Through contact,vectors,water,contaminated food
7. Vector control, immunity
EXERCISE
1A
2B
3B
4D
5C
6C
7B
8A
9A
10B
MODULE 18
TOPIC : MICROORGANISM AND THEIR EFFECTS ON LIVING THINGS
(b) When the time increase, the number of bacterial colonies increase.
(c) 222 (a) Petri dish with the pH 7 has the most bacteria colonies // Petri dish with the pH
2 has the least bacteria colonies.
pH valueNo. of colonies
25
610
107
(b)
(c)pH 7
MODULE 19TOPIC: MICROORGANISM AND THEIR EFFECTS ON LIVING THINGSIMPORTANT SCHEME
1
DiseasePathogenWays to spreading
CholeraBacteriaThrough contaminated food,water
DiphtheriaBacteriaAir
GonorrhoeaBacteriaContact
TuberculosisBacteriaThrough air
SyphilisBacteriaThrough contact
DysenteryProtozoaContaminated water & contaminated food
MalariaProtozoaThrough vectors
InfluenzaVirusThrough air
Dengue feverVirusVectors
Hepatitis BVirusThrough contact
Hepatitis AVirusThrough contaminated food
ChickenpoxVirusAir & contact
AIDSVirusThrough contact
RingwormFungiThrough contact
1(a) Y : larva Z : Pupa
(b) W : Use insecticide aerosol spray on adult mosquitoes// Put up mosquito nets/repellents to prevent from being bitten by adult mosquitoes Z : Destroy breeding grounds of mosquitoes by cleaning /draining
swamps,ponds & containers filled with water(c) When a person is bitten by a mosquito, the pathogens(virus dengue
fever) in the saliva of the mosquito enter the bloodstream of the person.2(a) R : larva S: Pupa
(b) because the flies only carry the pathogens
(c) destroy the breeding ground of houseflies by disposal waste food,decaying
matter & rubbish// burying //dispose//wrapping garbage properly
(d) When a housefly lands on food,pathogens are transferred from its legs or body to the food.
(e) Patient are treated with antibiotic / tetracycline/chloramphenicol3(a) Virus ; Fungi
(b) (i) Anopheles mosquito
(ii) When a person is bitten by a mosquito, the pathogens/protozoa in the saliva of the mosquito enter the bloodstream of the person
(c ) (i) Tuberculosis
(ii) To stimulate the production of antibodies by white blood cells
(d) Through sexual relationship
MODULE 20TOPIC: NUTRITION Question numberAnswer
1A
2D
3C
4D
5A
6A
7A
8D
9. 1. Malnutrition 2. Kwashiorkor
3. Rickets
4. Arteriosclerosis
5. Anorexia nervosa
6. Scurvy
MODULE 21TOPIC: NUTRITIONQuestion numberAnswer
1A
2A
3C
4A
5D
6C
7.
Part (A)
SHAPE \* MERGEFORMAT
Part B
(a) To study the effect of nitrogen on the plant growth.
(b) (i) Manipulated variable : type of solution
(ii) Respond variable : the colour of the leaves
(iii) Controlled variable : the size of seedling
(c) Test tube P : normal growth
Test tube Q : leaves turn yellow
(d) To synthesis protein/chlorophyll/help plants growth
8. (a) Nitrates
(b) Lightning, volcanic eruptions
(c) Nitrogen fixing bacteria, leguminous
(d) Decay bacteria, ammonium compound
(e) Nitrifying bacteria, nitrification
(f) (i) Denitrifying bacteria
(ii) Leaching
MODULE 22TOPIC: PRESERVATION AND CONSERVATION OF THE ENVIRONMENT1(a)Carbon dioxide // any greenhouse gases
(b) Combustion of fossil fuels// respiration// open burning
(c) Global warming
(d)Cause Glaciers and ice caps in the Artic & Antarctic to melt/ sea level will rise causing coastal flooding
// changes of normal weather patterns
2(a)depletes// become thinner
(b) ultraviolet rays
(c) To filter the ultraviolet rays// to protect the organisms from ultraviolet rays
(d) Cause cataract eye// skin cancer// weakened the immune system
(e)Mark picture show refrigerator and aerosol
MODULE 23
TOPIC : CARBON COMPOUND- ALCOHOL
Question NoAnswer
1B
2D
3C
4A
5D
6A
Living thingsSourcesMineral substances
Carbon, hydrogen, oxygen and nitrogenElements presentCarbon, oxygen ,
Metallic element
Combine with oxygen
Release a lot of heatEffects of heatOxides- unchanged
Carbonates of metals - decompose
Soluble in organic solventsSolubilitySoluble in inorganic solvents
ANSWERS FOR MODULE 24
TOPIC: CARBON COMPOUND- ALCOHOL
Objective Questions:
Question NoAnswerQuestion NoAnswer
1C9C
2D10C
3A11B
4A12B
5B13D
6C14D
7B15D
8A
(a)(ii)28 + 0.5 (cm3)
(b)The longer the time taken, the higher the volume of carbon dioxide gas
released
(d) 32(cm3)
ANSWERS FOR MODULE 25
TOPIC: CARBON COMPOUND SOAP
Question NoAnswer
Question NoAnswer
1D5D
2D6D
3D7A
4C8B
Structure Question: Section A
1(a)Substance X: Palm oil / Fat Substance Y: Soap
(b)To make the soap float to the surface
(c)
(d)
Sea waterMineral waterRain water
(
2(a)
(b)(i) the part that dissolve in water: I / hydrophilic/ head/ ionic head
(ii)the part that dissolve in oil : H / hydrophobic/ hydrocarbon tail
(c)saponification
(d)Soap can reduce the surface tension of water.ANSWERS FOR MODULE 26
TOPIC : MOTION -- INERTIA
Objective Questions
Question NoAnswerQuestion NoAnswer
1B4A
2C5D
3A6C
Structure question(a)(i)Wooden block A falls (vertically) on wooden block B and C(ii) The stationary inertia of the coin maintains its stationary condition
(b)(i)Drivers body thrown forward
(ii)By fastening seat belt
Section C - Experimenting
Find
Manipulated :
Mass of objectResponding
Motion of object
1HYPOTHESIS
Eg:
The greater the mass of the object, the difficult the object to move //
The more the mass of the object, the harder/difficult //
If the mass is more , so the object is hard to move
1m
2AIM OF EXPERIMENTTo study the effect of mass of object on the motion of the object
1m
3VARIABLES(a) Constant : Size of tin// the height of tins hang 1m
(b) Manipulated: Mass of tin 1m
(c) Responding : Motion of object/tin 1m
max 2 m
4APPARATUS AND MATERIALSTins, rope/ string, sand, retort stand // any place to hang the tins
Note : Must have all 1m
5METHOD1. Prepare two tins with the same size and hung up using rope
at the same height - pt 1 (1 m) 2. Fill one tin with sand and leave the other tin empty -pt 2 ( 1 m)3. Push the tins (with the same force) at the same time-pt3
4. The tin that is harder to swing is observed -pt4
maximum 3 marks
6TABULATION OF DATA 1m
7CONCLUSIONEg:
The greater the mass of the object, the difficult the object to move //
The more the mass of the object, the harder/difficult
1m
MODULE 27
TOPIC : MOTION
1.
WEIGHT ( Newton )
Block in AirEmpty BeakerBeaker + Water DisplacedBlock in WaterWater displaced
W
( N )B0
( N )B1
( N )W1
( N )B2 = B1 B0
( N )
a)10
16.54.55.5
b)14
21068
c)18
41359
d)20
314.58.511.5
Check out : W = W1 + B2
2. A ( 0.5 N )
3. D ( 7.0 N )
4.
a) The up thrust acting on iron block is equal to weight of water displaced .
b) W 2 W 1 = up trust @ W 3 W 1 = up trust
c ) ( i ) The up trust
( ii ) The volume / weight of water displacement / water level risen
d) Up trust equal ( = ) loss of iron block in water MODULE 28TOPIC: MOTION (THE CONCEPT OF SPEED, VELOCITY AND ACCELERATION) Objective Questions
Question NoAnswer
1B
2B
3B
4B
5A
MODULE 29TOPIC: FOOD TECHNOLOGY AND PRODUCTION
Q1 (i ) Instant coffee powder
(ii) Vacuum powder
(iii) Canned food
(iv) UHT milk
(v) Pasteurised fresh milk
(vi) Dehydration
Q2
1. Sweeter
2. Colouring
3. Anti-oxidants
4. Bleach
5. Flavouring
Q3
1. ( / )
2. ( X )
3. ( X )
4. ( / )
5. ( X )
Q4
1. D
2. A
3. B
4. B
5. B
6. D
7. D
8. C
9. A
10. C
MODULE 30
TOPIC :SYNTHETIC MATERIALS IN INDUSTRY
Synthetic Polymers
A.
Nylon / Polyvinyl chloride (PVC) / Polyesters ( Terylene) / Polyethene
PlasticsA.
1. Polymerization
2. Ethene /Ethylene
3. Polythene does not conduct electricityB.
Thermoplastics Perspex / polyethene / polystyrene / polypropene / Nylon / Terylene
Thermosets Teflon (PTFE) / Bakelite / Epoxy polymer / Melamine
C.
(i). The characteristics are:
( Hard and not flexible
( Do not soften or melt easily when heated
( Do not burn easily
( Do not conduct electricity
(Accept any suitable answer)
(ii). The four ways are:
( Recycling of plastic materials
( Cleaning and reusing plastic items
( Burning plastics in an incinerator
( Compressing and burying the plastic waste
(Accept any suitable answer)
MODULE 31TOPIC: ELECTRONIC
A: Wave length,
B: Amplitude, A2.
CHARACTERISTICS OF WAVES
ExplanationCharacteristics
The number of complete waves generated per second.Frequency, f
The distance moved by the wave in one second.Wave velocity, v
The distance between two successive crests or two successive troughs on the transverse wave.Wave length,
The maximum displacement of a wave particle from its equilibrium position or resting position.Amplitude, A
3.
Figure A Figure B
Frequency: HighFrequency: Low
Wavelength: ShortWavelength: Long4
5.
TYPE OF RADIO WAVEWAVELENGTH RANGEFREQUENCY RANGEAPPLICATIONS
Long waves, LW or Low Frequency, LF1000m 10000m30kHz 300kHzRadio communications
Medium waves, MW or Medium frequency, MF100m 1000m300kHz 3MHzRadio communications, AM radio broadcasting
Short Waves, SW or High Frequency, HF10m 100m3MHz 30MHzRadio communications
Very High Frequency, VHF1m 10m30MHz 300MHzRadio communications, FM Radio and TV broadcasting.
Ultra High Frequency, UHF10cm 1m300MHz 3 GHzRadio communications, TV broadcasting
Microwave1mm 10cm3GHz 30 GHzTV broadcasting, mobile phone, satellite communications
6.
EXPLANATION AEXPLANATION BEXPLANATION C
Long waves
Frequency up to 2MHz.
Travel along the Earth surface following its curvature. Medium waves
Frequency between 3 and 30MHz.
Reflected by ionosphere to the ground. Short waves and microwaves
Frequency above 30MHz.
Travel in straight lines and can pass through the ionosphere and out to space.
GROUND WAVESSKY WAVESSPACE WAVES
SKY WAVESSPACE WAVES GROUND WAVES
MODULE 32TOPIC: ELECTRONIC
1.
ELECTRONIC COMPONENTSSYMBOLFUNCTION
Aerial
To pick up all available radio waves with different frequencies within the range.
Inductor
Works with a variable capacitor to form a tuning circuit.
Variable capacitor
Works with an inductor to form a tuning circuit. Its capacitance can be adjusted to change the frequency of the radio in order to match the frequency of the radio waves transmitted from the station.
Diode
To act as a rectifier separating the a.f. signals from the amplified modulated r.f signal through demodulation.
Capacitor
To channel the flow of r.f. carrier waves into the Earth.
Transistor
To amplify the a.f. signals before sending them to the loudspeaker or earphone.
Resistor
Works with a transistor to amplify the a.f. signals
Transformer
To change the voltage of an alternating current.
2.
A: microphone
B: amplifier
C: oscillator
D: modulator
E: amplitude modulated radio waves
F: transmitting aerial
3. A: The function of microphone is to produce audio frequency signals.
B: The function of amplifier is to amplify the audio signals.
C: The function of oscillator is to generate radio frequency, r.f, signals.
D: The function of modulator is to combine audio signals and radio waves4.
A: receiver aerial
B: tuner circuit
C: amplifier
D: demodulator / rectifier / detector
E: loudspeaker5.
A: The function of receiver aerial is to receives modulated waves.
B: The function of tuner circuit is to select transmission channels.
C: The function of amplifier is to amplify the audio signals.
D: The function of is demodulator / rectifier / detector to separate audio signals from radio waves.E: The function of loudspeaker is to change audio signals to sound waves.Zinc oxide
Hydrogen
Calcium hydroxide
Hydrogen
CONDENSATION
BOILING
FREEZING
MELTING
SUBLIMATION
GASES
LIQUID
SOLID
MALE
FEMALE
44 + XY
44 + XX
ovum
22+X
It involved in fertilization contain chromosomes.
Gametes
Meiosis
A DNA unit which functions to code the heritable characteristics.
The process of cell division to produce gametes with half the number of chromosomes of the parent cell.
Gene
Mitosis
The process of cell division which takes place only in somatic cells (body cells).
A thread-like structures found in the nuclei of animal and plant cells.
Chromosome
Time/day
Explanation
The steps in Scientific Investigation
Aim
Hypothesis
Manipulated variable
Responding variable
Controlled variable
Observation: test tube P
Observation : test tube Q
type of solution
the colour of leaves
to study the effect of nitrogen on the plant growth
leaves turn yellow
normal growth
the size of seedling/place of experiment
The growth of plants will be affected when the plant lack in nitrogen.
Inorganic compounds
Organic compounds
Contains carbon elements
Similarities
Differences
(a)(i)
Hydrocarbon tail
Ionic head
hydrophobic
hydrophilic
Manipulated
The motion of an object is affected by its mass
Responding
Mass of tin/objectMotion of objectLess (empty tin)More (tin fill with sand)
Gamma rays
Ultraviolet
Infra-red
Microwaves
Radio waves
STF Science Remedial ( SPM ) ANSWER SCHEME
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