Lesson Exercise 5h 13 May
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Transcript of Lesson Exercise 5h 13 May
7/26/2019 Lesson Exercise 5h 13 May
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SEKOLAH MENENGAH SERI TEMASIK
MODEL EXAMINATION
EXERCISES
IGCSE
5H
EXERCISE NO :2 DATE: 13/5/2016
TIME : 10.50a.m.-11.55 a.m.
SUBMISSION DATE: 13/5/2016
T!"#/S$%&!"# : All topics
L'a()")* O%+'#&",' : i) To help student prepare for paper 3 of middle year
examination
Nam' :
Ca :
1 Dung beetles live in places where large herbivores, such as elephants, buffaloor cattle, also live. The beetles collect dung produced by the herbivores and
make it into a ball, which they roll away and bury.
Theylay
eggsonth
PREPARED BY: BENJAMIN TEE 1
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e buried ball of dung, so that when their larvae hatch they can feed on the dung. The adultsalso feed on the dung.
Fig. 1.1 shows a dung beetle rolling a ball of dung.
Fig. 1.1
(a) Dung beetles play an important role in the carbon cycle.
sing the information above, suggest how dung beetles can help a carbon atom inanimal dung to become part of a carbohydrate molecule within a plant.
!"#
(b) The buried dung adds nitrates to the soil.
$%plain how this can help plants to grow better.
!&#
(c) Farmers may use insecticides (pesticides that kill insects) on their land.
(i) $%plain why farmers use insecticides.
!&#
PREPARED BY: BENJAMIN TEE 2
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(ii) sing the information above, e%plain why using insecticides on land where cattle gra'ecould reduce the growth of grass.
!&#
PREPARED BY: BENJAMIN TEE 3
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& Fig. .1 shows a sperm cell.
nucleus
Fig. .1
(a) n Fig. .1, use label lines to label and name two structures that are found in allanimal cells. !&#
(b) *ame the organ in which sperm are produced. !1#
(c) +n investigation was carried out into the o%ygen use and energy use of sperm while they were atrest and while they were swimming.
For each measurement, the researchers calculated the amount of o%ygen and the amountof energy used by 1
- (one thousand million) sperm.
The results are shown in Table .1.
Table .1
o%ygen use units per energy use /oules per
1- sperm per hour 1
- sperm per hour
resting sperm & 0
swimming sperm 1" 10
(i) 2uggest why the researchers measured the o%ygen use and energy use for 1
-
sperm,rather than for a single sperm.
!1#
(ii) $%plain why more o%ygen is used when the sperm are using more energy.!&#
(iii) 3alculate
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the total power output of a group of 1- swimming sperm.
2tate the formula that you use and show your working.
formula
working
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(iv) 4n order to reach an egg, a human sperm has to swim from the top of the vagina to an oviduct,through a thin layer of li5uid.
$%plain how the shape of the sperm, shown in Fig. .1, reduces the energy re5uired to swim this
distance.
!&#
3.
The smell of food cooking can cause a person6s salivary glands to secrete saliva.
(a)(i)*amethistype
ofresponsetoastimulus.
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!1#
(ii) Describe how the information about the smell of the food travels from the nose to the salivaryglands.
!"#
(b) 7hen food has been taken into a person6s mouth, it is chewed by teeth and mi%ed with saliva.
Describe how the molar teeth help in the digestion of food.
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(c) 2aliva contains the en'yme amylase.
7hatis
an en'yme8
!&#