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