Science
Grade 8
Revision
i. Answer all questions
ii. Underline the most suitable answer
1.
2.
Diseases caused by bacteria and virus respectively are
i. Malaria, Dengue
ii. Typhoid fever, Common cold
iii. AIDS, Leprosy
iv. Pityriasis, Leishmaniasis
Animals with a muscular foot,
i. Mollusca ii. Arthropoda
3.
4.
iii. Annelida
iv. Cnidarian
A is a zone of a Bunsen flame
i.
Non Luminous zone
ii. Dark blue zone
iii.
Invisible zone
iv. Light blue zone
A. Interaction between the receptors and the effectors is known as
coordination.
B. Coordination the body organs by hormones is known as endocrine
coordination.
C. Coordination by nervous system is known as chemical coordination.
Correct answers are,
i. A and B
ii. B and C
iii. A and C
iv. A, B and C
5.
Which of the following pairs correctly gives an adaptation in
plants to minimize the rate of transpiration and an example plant (1) Leaves
reduced to spines - Kasa
(2) Presence of thin leaves
- Valisnaria
(3) Presence of thick waxy cuticle - Temple trees
(4) Leaves arranged in spiral manner around stem - Kanda
6.
When a food item is preserved by deep freezing the temperature is
maintained
i. Below 0 0 C
ii.Below -4 0 C
iii. Below -18 0 C iv. Below -80 C
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7.
8.
An example for a food preservative
i. Pectin ii. Benzoic acid
iii. Citric acid
iv. Saccharin
Which of the following type of microbes is used to make ethyl alcohol
(i)
9.
Lactobasillus (iii)
Acetobactor (iv)
Methano bactor
The brightest star in the sky
(i)
10.
Yeast (ii)
Venus (ii)
Pollux
(iii)
Sirius (iv) Proxima centaury
Answer the following question based on the following two statements
A- Sea anemone is a fish
B- It bisexual
(i) Both A and B are correct
(ii) Both A and B are incorrect
(iii)A is correct but B is incorrect (iv) B is correct A in incorrect
11. Given below are five statements given by five students .What are the correct
statements.
a. The sky you see is known as celestial sphere.
b. We cannot see both hemispheres of the celestial sphere at the same time.
c. When you want to observe the night sky, we must select a night with a cloudy
sky and no lights at all
d. Arrangement of stars across the celestial sphere could be identified as star
patterns.
e. The star pattern which seems to be moving in the celestial sphere is known as
Zodiac.
(1) a, and b only
(2)
a, b and c only
(3)
a, c, and d only (4) all
12. The type of microbes used to make bread is
(i)
Yeast (ii)
Acetobacter (iii)
Lacto bacillus
(iv) Ethano bacter
13. Which of the followings is incorrect?
1) Seasonal changes occur due to the revolution of the earth and tilt
2) Mercury and Venus have no sub-planets.
3) Phases of moon occur because of the revolution of the earth
4) Lunar eclipse occurs on a full moon day
14.Which of the following is incorrect about guttation
i. Water released in the form of liquid
iii. . Only water is released
ii. Occurs through hydathodes
iv. Mostly occurs during night
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15. Which of the following statements is incorrect regarding the circuit shown in
figure?
(1) X is an ammeter used to measure the electric current.
(2) Y is a voltmeter used to measure the potential difference.
(3) Voltmeter is connected in series to the circuit.
(4) This circuit has one dry cell connected.
16.
Which of the followings is incorrect?
(i) When number of dry cells connected in series is increased the brightness of
bulb increases
(ii) When number of dry cells connected in parallel is increased the
brightness of the bulb doesn’t change
(iii) Brightness of the bulbs increases, with the increase of bulbs connected in
series
(iv) Bulb can be lighted for a longer time when cells are connected parallel
17. Our environment consists with matter and energy. Correct statement related to
matter,
i. According to the Aristotle matter made of small particles.
ii. Matter made up particles.
iii. According to Democritus matter do not made of particles.
iv. According to modern experiments Aristotle’s idea is correct.
18. Substance which have highest melting point,
i. Lead
ii. Ice
iii. Aluminum
iv. Copper
19. Material with high resistance
i. Lead
ii.Copper
iii. Aluminum
20. Factor that do not need for combustion,
i. Carbon Dioxide
ii. Fuels
iii. Oxygen
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iv. Heat
iv. Nichrome
Paper II
1. (A) Given below shows the steps followed by a group of students to show that
starch is produced by the photosynthesis?
a) Explain the reason why the leaf is boiled in water?
b) What is the reason for boiling the leaf in alcohol?
c) When boiling the leaf in alcohol it is done by putting in a water bath.
Explain.
d) What is the reason for washing the leaf in water?
e) What is the colour change of iodine if the leaf contains starch?
(B). Given below shows an experiment carried out by a group of student in grade 8
i.
What is shown by this experiment?
ii.
Name a suitable aquatic plant for this
experiment
iii.
What is the observation when this set up is kept
in sun light?
iv.
What is the gas released by the aquatic plant?
v.
What is the experiment to test the above gas?
vi.
Mention 2 importance of the process of photosynthesis?
(C). Given below is an experiment done by a group of students study how a certain
process.
(a)
(d)
What is the process that they have planned to
study?
(b) Why did they fix a cellophane membrane to
the bottom of thistle funnel?
(c) Name a suitable living membrane for the
same practical
Name a suitable liquid to be filled in thistle funnel?
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(e)
(f)
(g)
What will be the observation after few minutes?
Explain the reason for this observation
Mention how this process is important for the plant
2) (A) Given below is a diagram of urinary system.
a) Name the parts A to H
b) What is the function of E
c) What are the excretory substances removed by this system
d) Name a disease associated with this system
e) Mention two ways to maintain this system healthy
(B) Complete the following chart reading nervous system
(a)
3) Some animals show different morphological features in the life cycle but some
do not show
i) Name an animal showing different morphological features in the life cycle
ii) Name 2 animals do not show different morphological features in the life
cycle
iii) What is metamorphosis?
iv) What are the main groups of organisms that show metamorphosis?
v) Metamorphosis of insects is of two types as complete metamorphosis and
incomplete metamorphosis
a. What is known as complete metamorphosis?
b. Name two insects that show complete metamorphosis
vi) Mention two importance of learning the life cycles.
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4. (A) Identify the following instruments
a. What is the direction of conventional current?
b. What is the instrument used to identify the direction of current?
c. A student set. an ammeter or center-zero millimeter, an electric motor, a dry
cell and a switch as in the following diagram
i. What is the observation when the circuit is
switch on and operated?
ii.
iii.
What happens when Inter change the terminals of the cell and observe
again.
(B)
There are number of effects of current electricity. One such is magnetic
effect.
a. What are the materials needed for making an electromagnet in the lab?
b. Draw the diagram of electro magnet made using the above materials
c. Name three factors affecting the strength of an electromagnet
d. Write two other effects of current electricity
5. (A) . Given below shows how a lunar eclipse occurs.
(a)
(b)
(c)
(B)
What are the types of eclipses occurring at A,B, C respectively
On what day a lunar eclipse occur?
What is the reason for occurrence of phases of the moon?
Since ancient time celestial bodies were venerated as Gods. Later ancient
Greeks observed various imaginary pictures through the star patterns which
they have heard in Falk tales or in mythology.
(i)
Name the constellation to which the Polaris belongs, and mention the
month in which this star can be observed in the night sky.
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(ii) Given below is a constellation.
(a) What is name of this constellation?
(b) What is the time duration this can be clearly visible to Sri Lanka
(i)
(C)
Mention two uses of known the star patterns.
Natural disasters are naturally occurring destructive incidents, without the
mediation of man, causing harm to human lives, property, environment and
economy.
(a) What is known as drought?
(b) Natural reasons as well as human activities may affect the drought to
cause. Mention two natural reasons for causing drought
(c) Mention two human reasons for causing drought
(d) Write two things that can be done for drought disaster management
6.
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7.
9. There is a vast diversity of organisms. They are classified in to various groups by
considering different criterion
i. What is known as classification?
ii.What are the two main groups of animals
iii. Match the correct features to the relevant group of organisms and examples
Features
Examples
have radially symmetrical body
Earthworm, leech
Group of
organisms
Annalida
They are bilaterally symmetrical. Butterfly, Crab, Insects
Soft bodied animals.
Possess a muscular foot.
Mollusca
body possesses an external
skeleton, have jointed
appendages
Vermiform, Body consists of
segments
sea anemones ,Hydra
Cnidarian
Snail , Slugs
Arthropoda
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