(skema)koleksi Trial Science Pmr Form 2

55/2 SCIENCE PMR

PENILAIAN MENENGAH RENDAH

SCIENCE KERTAS 2 PERATURAN PEMARKAHAN

UNTUK KEGUNAAN PEMERIKSA SAHAJA

Peraturan pemarkahan ini mengandungi 10 halaman bercetak

m/surat 2.

skema

markah

7

3.

4. 5.

6.

7.

a) b) Pain receptor c) The arm have thick epidermis // The arm have fewer receptor d) Touch receptor a)K-pain receptor L-touch receptor M- pressure receptor b) P – made up of dead cells Q- contains receptor, blood capillaries and sweat glands/detect temperature that better than normal a)Nose – garbage lorry Hand –hot kettle Ear – radio b)A – chocolate B – bitter groud C – dried fish a) P- semicircular canal Q –cochlea R – ear ossicles b) Q – convert sound vibration to nerve impulses R – amplifies sound waves c) Microphones / loudhailer / earphones / loud speaker a) P- auditory canal Q – cochlea R – semicircular canal b) P –transmits sound waves to the eardrum Q – detect and changes sound vibration into impulses R – helps to balance the body a)P-ossicles Q –cochlea R –ear drum b)detects vibrations and converts them into nerve impulses

5 6 6

6

6

8.

d) semicircular canals a) P-semicircular canal Q – cochlea R – eardrum b) P-helps to balance the body //detect movement of head// to maintain the body equilibrium. Q – converts sound vibration into nerve impulses // transform sound vibration into impulses R- vibrates and transfer sound waves to the ossicles//separates outer ear from the inner/magnify sound vibration.

5

9.

6

10.

b) P- collect sound waves Q-carries / sends nerve impulses to the brain C) Eustachio tube Semicircular canal a)P- ossicles Q –cochlea R- ear drum b)P – to magnify / amplify sound vibration Q – to change sound vibration into pulses R – to vibrate when receives sound wave Structure P,Q,R must be stated

5

11.

5

12.

Ear drum – vibrates according to the frequency of the sound waves. Cochlea – convert the sound waves into nerve impulses a)P – ear Q- ossicles R – auditory nerve

5

13.

14.

c) Q – amplifies the sound vibrations R – send impulses to the brain a) M- lens K – retina b) pupils  lens c) M – focuses light K – receives light stimulus and send impulses to the brain a)M – lens N – retina P – vitreous humour b)M – focuses the light onto the retina N – formed image

6 5

15.

a)(i) (ii)Retina / yellow spot b)(i) Y : short sightedness (ii) Eye ball is too short / the lens is too thin

16.

(iii) a)X – monocular vision b)X- at the side of the head c)X – wide field of vision d)Owl & monkey – vision Y

Z: long sightedness

Y – stereoscopic vision Y – in front of the head Y – can determine the distance of object/ can see 3d Cow & fish – vision X 4 pair correct – 2 marks 2–3 pairs correct – 1 mark 0-1 pair correct – 0 mark

5

8

17.

5

18.

a) b)Phototropism c)Shoot d)To obtain sunlight for photosynthesis a)(i)Phototropism / Hydrotropism / Geotropism (ii)Phototropism – to get sunlight for photosynthesis //Hydrotropism – to get water from the ground Geotropism – enable the roots to grow deep into ground The imports must follow the answer in a)(i) b)(i)Anhydrous calcium chloride – absorb water from atmosphere

7

19.

20.

21.

(ii)Water – to stimulate the roots towards water c)(i)Gravity d)To carry dissolved minerals salt into the plant a)(i) Protein (ii) Milk // Egg // Fish // Any suitable answer b)Brick red precipitate is formed c)Kwashiorkor d) (i) Stomach (ii) amino acids a) X- glucose Y- protein b) glycogen c)(i) X : to provide energy Y ; repair / build new tissues d)diabetes (mellitus) kwashiorkor e)small intestine Mouthoesophagusstomachsmall intestineanal/rectum

6

8

5correct – 2m, 3 correct -1m b)Q will contract and relax c)carbohydrates : glucose protein : amino acid fats : glycerol and fatty acid d)(i)visking tube (ii)the enzyme in saliva functions best at body temperature

8

22.

5

23.

24.

25.

26.

27.

b) Absorption of digested food // food digestion ends here. c) Protein – brick red precipitate Starch – dark blue // blue black d) B- oesophagus G - anus a) P - stomach Q – pancreas R – small intestine b) (i)protein ii) S (liver c) carbohydrates – glucose Protein - amino acid Fats – fatty acid and glycerol d) small intestine a)(i)The enzyme in saliva functions best in body temperature 37oC. (ii)Mouth (iii)Salivary gland b)Carbohydrates – bread/ rice/bananas Proteins – milk/fish/eggs Vitamins - fruits a)(i)glucose // simply/tiny/small molecules//simple sugar (ii) the molecules are very small and can pass /go/diffuse through the visking tube// the visking tube is porous/has very tiny holes (iii) glucose was not found in the distilled water//starch is not digested//no change in color b)(i) iodine solution (ii)Benedict solution or vice versa c) carbohydrates a)Because it is body temperature / because it is optimum temperature Reject if body temperature 27oC b)To test the presence of stach c) (i)glucose / maltose (ii)amylase digested / break down starch into glucose/maltose d) i)small intestine (ii)blood a)(i)Organism B (ii)Because it makes its own food. b)(i) Four// 4  Paddy plant→Grasshopper→Lizard→Eagle - Paddy plant→Rat→Snake→Eagle  Paddy plant→Rat→Eagle -Paddy plant→Rabbit→Eagle 1 mark (either one answer) c)The other animals in the food chain will starve and reduce in numbers d)There will be a decrease in the paddy population// There will be an increased in snake population e)The sun

9

6

6

6

7

28.

29.

(a)Plantmothpraying mantislizard plantgrasshopperpredator buglizard plantgrasshopperpraying mantislizard plantherbivorous bugpredator buglizard any 2 or other suitable food chains b)sun//sunlight//solar(energy) c)lizard d)prey-predator e)plant/tree//green plants f)(the population of)the consumers(e.g.: grasshopper, lizard, moth, herbivorous bug) decrease/die//move to another place a)(i)Several type of population that interact together in a habitat. (ii)consist of all populations of organism in a habitat

7

6

30.

31.

b) c)(i)Producer-s (ii)Secondary-R d)Some energy is lost as heat when the organism carries out its life processes / respiration / excretion / growth a)P: secondary consumer Q:tertiary consumer b) 200 c) insects will be reduced/ less incest / insects go away d)(i) it makes its own food/produces its own food/ by photosynthesis (ii) birds/chickens and other suitable answer. a) Caterpillar Sparrow Paddy

6

Snake Grasshopper

Frog 7

32.

33.

34.

b) Snake c)(i) Grasshopper // Caterpillar // Sparrow (ii)Biological control The population of frog decrease . Caterpillar and Grasshopper or Sparrow and frog. i)rat / small bird ii)eagle/snake padiratsnakeeagle padismall birdssnakeeagle padirateagle padismall birdseagle i)population of snake increases/population of eagle increases/population of padi decreases ii)population of rat decreases/population of snake decreases/population of small bird decreases rat biological control/pelihara owl Commensalism Remora fish got benefit while shark does not gain anything or unharmed by it. Picture 3 i)using biological control ii)low cost/does not cause pollution//does not destroy or kill other organism(an two) a)Parasitism/parasitisme b)The rafflesia benefit and host is negatively or adversely affected c)tapeworm in human intestine//ticks and dog//mistletoe and tree//ice on human head any suitable answer d)biological control//oes not cause air pollution//cheap/not costly//the pest is not resistant to predator v) predator does not kill orgasinm other than its specific prey. Any two answer

8

6

6

35.

i)to show the sunlight is needed for photosynthesis// to investigate whether sunlight is required /needed/necessary for photosynthesis ii)to avoid /prevent/block the leaf from (exposure) to sunlight

6

36.

ii)the ethanol/alcohol used )to remove the chlorophyll from the leaf//decolourised the leaf /dissolve chlorophyll -sustaining/ maintain the carbon dioxide and oxygen in the air. -helps to absorb excess carbon dioxide in the atmosphere and replace the oxygen that is use during respiration. (accept any suitable answer) a)To absorb carbon dioxide b)To remove starch from the leaf // To destarch the leaf. c)(i)Leaf from plant Q (ii)Plant Q is able to carry out photosynthesis in the presence of CO2. Carbon dioxide

Water

Chlorophyll

Glucose

Oxygen

7

Sunlight ( 4 correct = 3 marks ) ( 3 correct = 2 marks ) ( 2 correct = 1 mark ) 37.

38.

a)P: electrolysis Q:filtration R:evaporation b)P:to separate break down compound into its element Q:to separate an insoluble solid from liquid R:to separate a dissolved solid from a liquid a)X:condensation Y:boiling b)i_colourless//tasteless//odourless//boiling point at 100oC//has density of 1gcm-3//a poor conductor of heat/poor conductor of electricity c)(i)boiling point higher (than 100oC)

6

7

39.

ii) iii)heat is absorbed a)Distillation

9 c)To cool down the hot water vapour d)Condensation e)Distilled water f)It has no mineral salts g)Filtered water has microorganisms and dissolved substances while distilled water does not h)Boiling condensation

40.

a)(i)Oxygen (gas) : Odorless // Colourless // Support the combustion (glowing wooden splinter rekindles) // soluble in pyrogalol solution Note : accept any suitable answer

Water Air

41.

42.

43.

44.

45.

46.

Notes : level of water for N must be higher than L level of water for both test tube must be lower than level of water in the beaker. (iii) Burning wooden splinter extinguishes // Bicarbonates indicator turns from red to yellow // lime water turns into cloudy Notes: Should have name of material and observation b) Carbon + Oxygen  Carbon dioxide + energy P1 P2 Note: P1 and P2 correct award 2 marks P1 correct P2 wrong award 1 mark P1 wrong, P2 correct award 0 mark c)(i)The condition of the bread remain the same (ii)The container does not contain water and microorganism a)(i)add water (ii)soap/detergent/toothpaste/baking powder/any other alkaline substances b)(i)boiling point (ii)liquid to gas (iii)the boiling point increase (iv) higher than point Q) a)M:oxygen N:hydrogen b)(i)Sulphuric acid//hydrochloric acid//nitric acid (ii)To speed up the reaction / (electrolysis)process of water c)Hydrogen & oxygen d)M-lighted the glowing splinter N-produce a ‘pop’ sound a)electrolysis b)(i)(dilute) sulphuric acid/(dilute) hydrochloric acid (ii) to conduct electricity better/to enable electric current to flow in water c) produces a ‘pop’ sound d) 2:1

a)(water) electrolysis b)(i) anode (ii)cathode c)electrical energy to chemical energy d)oxygen e)2:1 a)(i)oxygen (ii)a glowing splinter burst into flame //test with a glowing splinter and it will burst into flames or similar answer b)oxygen will be collected at Q/hydrogen will be collected at P c) 20cm3 d)(i) to coagulate the fine solid particle or similar answer (ii)fine suspended particles are removed or similar answer e) K:pH value decreases / becomes dilute/less alkaline M: pH value increases //become dilute// less acidic f)because it is too costly// too expensive/not economical or similar answer a)(i)to determine the end/neutral point of the mixture (ii) the (green) colour at the end/neutral point can be clearly observed b)hydrochloric acid + sodium hydroxide sodium chloride + water all must be correct – 2marks

Acidic Lime juice Vinegar solution Carbonated drink Fresh milk

Alkali Soap solution Bleach solution Tooth-paste solution Magnesia of milk 5-6 correct – 3marks 3-4 correct – 2marks 1-2 correct – 1marks

47.

48.

49. 50.

A reaction between an acid and alkali to form salt and water Acid + Alkali Salt + Water Solution K : Hydrochloric acid // Sulphuric acid // Nitric acid Solution L : Sodium hydroxide // Potassium hydroxide // Ammonium hydroxide (i) Green (ii) Acidic solution (i) A dilute alkali is used to reduce pain caused by insect bite (ii) Alkali in toothpaste helps to neutralise the acid around our teeth (iii) Slake lime (Calcium hydroxide) is used to neutralise acidic soil (iv) Milk of magnesia (antacid) is used to neutralised the excess acid in the stomach *Choose any two suitable answers a)(i)Green (ii)Neutralization (iii)Sodium chloride Water acidic Alkaline Lemon//apple//tomato Toothpaste//milk of magnesia//soap pH7 toothpaste is an alkaline, it can neutralize acid in mouth Q:sedimentation tank R:chlorination tank (i)Slaked lime: to reduce the acidity of the water Reject: to neutralize water (ii) Alum: coagulate sediments/impurities into large particles. i)educate the public on the importance of controlling water pollution ii)detergents that are biodegradable should be used iii)enforment of laws to prevent the dumping of rubbish into the river.

51.

52.

53.

Accept any suitable answer a)to measure air pressure b)pressure of the air increases c)temperature increases, air pressure increases d)(i)siphon (ii) rubber sucker e) volume of air a)S- to suck liquid from container b)(i)pressure inside the drinking straw decreases (ii)pressure decreases/pressure inside air decreases Water can be suck/air do not decreases/pressure inside straw do not decreses Bicycle pump/spraying pump. a)(i)to remove the air inside the flask//similar answer (ii)the coloured water shoots/rushed/enter/moves into the flask//similar answer (iii)the air pressure outside is higher than the pressure inside the flask// the pressure inside the flask is lower than the air pressure outside the flas//similar answer (iv)air exerts pressure b)(i)blow into the packet//put the packet into hot water//any logical answer

Both diagram must be correct

54.

55.

56.

57.

58.

59.

60.

a)The box has move in a certain distance b)work done=force X distance =500N X1.2m =600Nm c)force is decreased, thus the work done is decreased d)(i)situation Q (ii)the box has to overcome gravitational force Spring balance To measure weight//force 6N Work done=force X distance=70N x 3.5m =245N a)pulling force b)magnetic force newton work done=force X distance = 500 x 8 = 4000J Power= work done /time taken =4000/40 =100watt a)(i)gravitational force (ii)550N (iii)550 x 1.2=660J (iv)Power = work done / time =660/6 =110 watt b)work done will be the same c)frictional force a)(i)roller, wheel, putting oil between contact surfaces, using air as crushion between the surfaces and any other suitable answer. (ii) disadvantages(slows down moving objects, wears out tyres, machine parts, shoe,produce heat, produce noise pollution. b) gravitational force, electrostatic c)(i) (ii)work done=force x distance=(30 x 10)N x 50m =15000Nm =150kJ (iii)power=work done / time =15000/(2x60s) =125W a)Endoskeletal / Endoskeleton system b)(i) Exoskeletel / Exoskeleton system (ii) Hydroskeletal / Hydroskeleton system c)Buoyancy // Buoyancy of water d)(i) -Its skeletal system not able to support its huge body weight. -Its weight will crush its internal organ J = Exoskeleton K = Endoskeleton L = Hydrostatic (skeleton) Reject: Wrong spelling K – Cat, Crocodile (any vertebrate) L – caterpillar / leech Note: accept any suitable answer. p1- Contains air sacs / air space (inside the stems and leaves) p2 – Supported by water bouyancy // make it light and float

61. X

Cupboard R Cupboard S Cupboard T * the ‘X’ must be located at the top, middle and lower part of cupboard S, R and T

62.

63.

64.

respectively. (i) (Cupboard) T (ii) (It has the) lowest centre of gravity (iii) T  S R (i) (It) spreads out its legs The stability is increased by increasing the base area (when the giraffe spreads out its legs) a)(i)Model P (ii) the centre of gravity is lower

c)(i)spread out his leg/with his legs wide again (ii)to lower the centre of gravity / to increase base area a)(i) second // 2 (class lever) (ii)the load is between the fulcrum and the effort / the load and effort act in opposite direction. b)Q need less effort than P to pull out the nail c)30kg x X = 25kg x 11.2m 30X=30 X=1m

(i)first class lever / first class/ 1 Reject one class (ii)less effort is needed/less energy is used/make the work easier b)stapler – 3rd class lever tin opener – 2nd class lever c)600N x 1.6m = distance x 400N 600N x 1.6m = distance 400N Distance = 2.4m