Page 26 - Genius PBD Science Year 4

ANSWERS

Medium rate of breathing:
UNIT 1 Scientific Skills
SUMMATIVE PRACTICE 1 Walking, jogging, going up
the stairs
1.1 Science Process Skills
Objective Questions High rate of breathing:
1. (a) Ear Running, cycling, swimming
(b) Tongue 1. B 2. C 3. B 4. B 5. C (b) Activities that are more
vigorous (running quickly
2. Can absorb Cannot absorb Subjective Questions and swimming) cause the
water water rate of breathing to increase
1. (a) The grasshoppers in glass K
die faster compared to the compared to other activities.
Towel Mirror 5. Student’s answer
grasshoppers in glass M.
Handkerchief Plastic bag (b) The grasshoppers in
Sponge Eraser glass K receive lesser 2.2 Excretion and Defecation
oxygen compared to the
Socks Buoy grasshoppers in glass M. 6. (a) waste products
(c) (i) Lifespan of grasshoppers: (b) faeces, anus
3. (a) The circuit is not connected 7. (a) skin
properly. / The bulb has Responding variable (b) carbon dioxide
burned out. (ii) Size of glass: Manipulated (c) water vapour
(b) The plant is not watered / variable (d) kidneys
does not get enough sunlight. (d) The bigger the size of the (e) urea
4. (a) The larger the size of the glass / the amount of air, (f) water
magnet, the more paper clips the longer the lifespan of a (g) mineral salts
it can attract. grasshopper. (h) undigested food
(b) (i) Size of paper clips (i) anus
(ii) Size of magnet UNIT 2 Humans 8. (a) (i) To prevent illnesses
(iii) Number of paper clips because through
attracted 2.1 Human Breathing Process excretion and defecation,
(c) The operational definition for we can eliminate
the strength of a magnet is 1. (a) (i) Nose products of excretion
the number of paper clips (ii) Trachea and faeces that are not
attracted to the magnet. (iii) Lungs needed by our body.
(d) More than 18 (b) (i) two (ii) Through defecation, we
(e) (ii) lungs can eliminate faeces that
(iii) nose can be poisonous when
5. (a) Shoot responds to sunlight. (iv) trachea accumulated in our body.
(b) (i) direction of light (v) lungs (iii) To prevent diseases such
(ii) direction of shoot growth 2. (a) (i) Draw from the nose to as gallstone, blood in
(iii) type and size of plant, the lungs through the urine or cancer which are
amount of water used to trachea caused by incomplete
water the plants (ii) Draw from the lungs to excretion and defecation
(c) Seedlings, black box, soil, pot, the nose through the process.
water trachea (b) It is important to eliminate
(d) 1. Two seedlings of similar (b) Inhalation: Nose → Trachea waste products that are
size are placed in two → Lungs not needed by the body so
black boxes with holes Exhalation: Lungs → Trachea that it will not accumulate in
cut at different places. → Nose the body and become toxic
2. The apparatus was put 3. Inhalation: or poisonous. A balanced
aside for 5 days. (a) upwards, enters diet intake especially food
3. The condition of the (b) more, less that contains fibre such
seedlings is observed Exhalation: as vegetables and fruits
after 5 days. (a) downwards, leaves are needed to prevent
(e) The seedlings grow towards (b) more, less constipation.
the holes. 4. (a) Low rate of breathing: 9. Student’s answer
(f) Shoot responds to sunlight. Sleeping, studying, watching
television

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13 Jawapan Genius PBD SCIENCE YR4.indd 1 19/10/2022 5:13 PM