8th Standard Basic Science Annual Exam Question Paper 2021-22 Kerala Syllabus

Practicing with Class 8 Basic Science Question Paper Kerala Syllabus and Annual Exam Question Paper 2021-22 will help students prepare effectively for their upcoming exams.

Class 8 Basic Science Annual Exam Question Paper 2021-22 Kerala Syllabus

Time: 2 hrs
Max. Score : 60

Instruction:

• The total cool off time for Physics, Chemistry and Biology is 15 minutes. Read the questions carefully and understand them during this time.
• Answers are to be written in the order Physics, Chemistry and Biology. The time for each section is 40 minute. The answer books must be returned to the teacher after writing each subject.

Physics

Time: 40 minute
Score:20

Answer any FOUR questions from 1 to 5. (Each question carries 1 score) (4 × 1 = 4)

Question 1.
Observe the relation in the first pair and complete the second pair. (1)
Electric charge:coulomb ::
Capacitance: ___________
Answer:
farad

Question 2.
How many second make one solar day? (1)
(24 s, 60 s, 86400 s)
Answer:
86400 s

Question 3.
Designing the shape of an object in order to reduce friction is ___________. (1)
Answer:
Streamlining

Question 4.
Which of the following has more susceptibility?
(Steel/ Soft iron)
Answer:
Soft Iron

Question 5.
The following figures depict, two electro-magnets made from two iron nails of same size. Which is the strongest electromagnet?

Answer:
(a)

Question 6.
a) The radius of curvature of a concave mirror is 40 cm. Find the focal length of the mirror. (1)
b) Which type of spherical mirrors are used as rear view mirror in vehicles? (1)
Answer:
a) Focal length, f = \(\frac{R}{2}=\frac{40}{2}\) = 20 cm
b) convex mirror

Question 7.
a) Draw magnetic lines of force between the given poles of magnets.

Answer:

b) Write any two peculiarities of magnetic lines of force.
Answer:
i) Magnetic lines of force do not in¬tersect one another,
ii) Magnetic lines of force bend side-ways, when like poles of magnets come near each other.

Question 8.
1 mm is the least count of a metre scale.(l)
a) What do you mean by least count? (1)
b) Arrange the following units in ascending order of their values. (1)
(μm, km, nm, cm)
Answer:
a) The smallest length that can be accurately measured using a metre scale is its least count.
b) µm < pm < cm < km

Question 9.
Observe the figure.

a) Identify the device. (1)
b) When you touch the metallic sphere of this device with a charged object, what do you observe? (1)
Answer:
a) Electroscope
b) The leaves of the electroscope repel each other.

Question 10.
Classify the following as acceleration and retardation. (2)
a) A ball rolling on a level ground.
b) A train starting from station.
c) Motion of a stone thrown up, when it goes up.
d) A coconut falling from a coconut tree.
Answer:
Acceleration – b, d
Retardation – a, c

Question 11.
The weight of the air column over unit area of earth’s surface is atmospheric pressure.
a) What is standard atmospheric pressure? (1)
b) Name the instrument used to measure atmospheric pressure. (1)
Answer:
a) The weight of an air column above unit area on the surface of earth at sea level is considered as one atmospheric pressure. This is equivalent to the weight of mercury column of height 0.76m and unit area of 1 m2. This is standard atmosphereic pressure.
b) Barometer

Question 12.
Two identical balloons one filled with water and other with kerosene of equal quantity.

a) Identify the balloon filled with water. (1)
b) Why is the expansion of balloons appear different in figures (a) and (b)? (1)
Answer:
a) b
b) Water has higher density that kerosene. As density increases, liquid pressure.

Question 13.
Two immiscible liquids A and B of densities
0. 8g/cm³ and lg/cm³ respectively are taken in a beaker.
a) Which liquid comes on the upper layer? (1)
b) Give reason. (1)
Answer:
a) Liquid A
b) Liquid having lowe density floats above the liquid having greater density.

Answer any TWO questions from 14 to 16. Each question carries 3 score. (3 × 2 = 6)

Question 14.
a) Complete the following diagram by depicting the path of reflected rays. (2)
Answer:

b) Write any two features of the image. (1)

Answer:
Inverted, Real

Question 15.
Production of sound in a manner unhealthy, to human beings is noise pollution.
a) Write any two harmful effects of noise pollution. (1)
b) Write any two methods to minimize noise pollution. (2)
Answer:
a) i) Leads to deafness
ii) Causes mental stress

b) i) Plant as many trees as possible,
ii) Ensure that silencers in vehicles work properly.

Question 16.
The following figure depicts the path of an object which takes 10s to travel from P to R through Q at uniform speed. Observe the fig¬ure and answer the following questions.
a) What is the speed of the object? (1)
b) Among velocity and speed, which one is a vector quantity. Why? (2)

Answer:
a) Speed = \(\frac{\text { Distance }}{\text { time }}=\frac{320}{10}\) = 32 m/s
b) Velocity, when velocity is stated, direction also should be mentioned along with magnitude.

Chemistry

Time: 40 minute
Score : 20

Answer any 3 questions from 1 to 5. (1 score each) . (3 × 1 = 3)

Question 1.
Boiling point of water is …………………… (1)
Answer:
100° c

Question 2.
Magnesium + Hydrochloric acid → Magnesium chloride + Hydrogen + Heat Which type of reaction is this? (1)
(Exothermic reaction, Endothermic reaction, Photochemical reaction)
Answer:
Exothermic reaction

Question 3.
Changes that are permanent and new molecules formed are called …………… (1)
Answer:
Chemical changes

Question 4.
Monomer of the polymer Rubber is ___________ (1)
Answer:
Isoprene

Question 5.
Haven’t you noticed the caption “Shake well before use” in certain medicine bottles. Which class does the substance in them belong to? (1)
(Solution, Colloid, Suspension)
Answer:
Suspension

Answer any 4 questions from 6 to 10. (2 scores each) (4 × 2 = 8)

Question 6.
Complete the table:

Element	Symbol	The basis of naming
Germanium	Ge	(a)
(b)	Cu	Latin name

Answer:
a) Name of the country Germany
b) Cuprum

Question 7.
Malleability and ductility are the properties of metals.
a) Which is the most malleable metal? (1)
b) Which is the most ductile metal? (1)
Answer:
a) Gold
b) Platinum

Question 8.
What are the changes that happen to the following properties of particles in a substance when heat is absorbed? (2)
a) Energy of particles
b) Attraction between particles
c) Distance between particles
d) Movement of particles
Answer:
a) Increases
b) Decreases
c) Increases
d) Increases

Question 9.
Following are the observations when a student added soap solution to two samples of water collected from two different sources.

Sample	Observation
Water collected from source 1	Lathes easily
Water collected from source 2	Does not lather easily

a) Which one of these is hard water? (1)
b) Which salts are responsible for the hard-ness of water? (1)
Answer:
a) Water collected from source – 2
b) Chlorides and Sulphates of Calcium and Magnessium.

Question 10.
Thermoplastics and thermosetting plastics are two different types of plastics.
a) Which one of these can be recycled? (1)
b) Give an example for thermosetting plastics. (1)
Answer:
a) Thermoplastics
b) Bakelite

Answer any 3 questions from 11 to 15 (3 scores each) (3 × 3 = 9)

Question 11.
Match the table

Mixture/ Occasion	Method of separation	Property used for separation
Mixture of water and acetone	Centrifugation	Small difference in the boiling point of components
Mixture of petrol and kerosene	Distillation	Difference in the mass of components
To separate blood cells from blood	Fractional distillation	Large difference in the boiling point of components

Answer:

Mixture of water and acetone	Distillation	Large difference in the boiling point.
Mixture of Petrol and kerosene	Fractional distillation	small difference in the boiling points
To separate blood cells from blood	Centrifugation	Difference in the mass of components.

Question 12.
NaCl is the chemical formula of common salt.
a) Which elements are represented by the symbols Na and Cl? (1)
b) Find the total number of molecules and atoms in 5H₂SO₄ (2)
Answer:
a) Na- Sodium
Cl – Chlorine

b) Molecules – 5
No. of atoms – 5 × 7 = 35

Question 13.
Two cotton pieces are soaked in Silver bromide solution. One is kept in direct sunlight and the other wrapped in a black cloth.
a) What do you observe? (1)
b) Which form of energy was responsible for this chemical change? (1)
c) What is the common name of this type of reaction? (1)
Answer:
a) One kept in direct sunlight gets darkened. Wrapped in black cloth does not undergo any change.
b) Light energy
c) Photo chemical reaction

Question 14.
Some solutions are given below.
(Brass, Sugar solution, Mixture of alcohol and water, Soda water)
a) Which among these has solid solute and solid solvent? (1)
b) Which are the solute and solvent in the mixture of alcohol and water? (1)
c) Which among these has gaseous solute? ( 1)
Answer:
a) Brass
b) Solute – alcohol Solvent – water
c) Soda water

Question 15.
Iron is a metal that corrodes fastly.
a) Write any two situations that favour corrosion of iron. (1)
b) Copper nails are preferred to Iron nails in coastal areas. Why? (1)
c) Write any one method to prevent the corrosion of Iron. (1)
Answer:
a) Presence of air, presence of water
b) Presence of salt in water speeds up the corrosion of iron. So in coastal areas copper nails are used instead of iron nails.
c) Paint, use non metallic covering

Biology

Time: 40 minute
Score: 20

Answer any 4 questions from 1 to 6. Each carries 1 score. (1 × 4 = 4)

Question 1.
Identify the word pair relation and fill. (1)
a) Leucoplast : Food storage;
Chloroplast : ___________
b) Animal cell : Theodor Schwann;
Plant cell : ___________
Answer:
a) Chloroplast: Photosynthesis
b) Plant cell – M.J. Schleiden

Question 2.
Write the name of the connective tissue which perform the following functions. (1)

• Conduction of materials
• Makes the body resistant to diseases

Answer:
Blood

Question 3.
Correct the mistake if any in the underlined part of the given statements. (1)
a) The ovum is produced by the oviduct.
b) Amniotic fluid protects the foetus from dehydration.
c) Fertilization takes place in the uterus.
Answer:
a) Ovary
c) Oviduct (Fallopian tube)

Question 4.
Find out the odd one and write the common feature of others. (1)
(Gray Giant, Ankora, Muscovy, White Giant)
Answer:
Muscovy. Others are varieties of rabbit.

Question 5.
Write down the name of any two organizations that work for the protection of nature. (1)
Answer:
IUCN (International Union for Conservation of Nature)
WWF (World Wide Fund for Nature)

Question 6.
Cocos nuficfera is the scientific name of coconut. Identify the level of classification indicated by the underlined part. (1)
Answer:
Genus

Answer any 5 questions form 7 to 13. Each carries 2 score. (2 × 5 = 10)

Question 7.
Observe the figure of Pollen grain given below and answer the questions.

a) Identify the part indicated as ‘X’ (1)
b) Write the change that takes place in ‘X’ after pollination. (1)
Answer:
a) X: Generative nucleus
b) Generative nucleus divides to form two male gametes.

Question 8.
The various levels of classification of human beings based on the six kingdom classification are given below. Complete the table suitably. (2)

Domain	Eukarya
Kingdom	a
Phylum	Chordata
Class	b
Order	Primates
Family	Hominidae
Genus	c
Species	d

Answer:
a) Animalia
b) Mammalia
c) Homo
d) Sapiens

Question 9.
Different stages of preparation of the slide, to observe plant cells through microscope are given below. Write them in the correct order. (2)

• Wash the stained section in clean water and place it in the glycerin on the slide.
• Take thin cross sections of the material to be observed.
• Place a cover glass over the material.
• Put the thinnest and complete sections in stain.

Answer:

• Take thin cross sections of the material to be observed.
• Put the thinnest and complete section in stain.
• Wash the stained section in clean water and place it in the glycerin on the slide.
• Place a cover glass over the material.

Question 10.
Observe the pictures of animal tissues given below and answer the questions.

a) Identify the tissues ‘X’ and ‘ Y’. (1)
Answer:
X – Nervous tissue
Y – Epithelial tissue

b) Write any one function of the tissue indicated as‘X’. (1)
Answer:

• Control and co-ordinate all body activities.
• It enables to respond identifying the changes inside and outside the body and helps to give proper response (any one)

Question 11.
Analyse the following statement and give reason. (2)
Changes related to adolescence are more rapid in girls than in boys.
Answer:
The parts of the brain that control physical and mental changes develop rapidly in girls.

Question 12.
Choose the appropriate one from the box and complete the table.
a) Nilgris
b) Periyar
c) Silent Valley
d) Kadalundi
e) Malabar Botanical garden

i) Wild life Sanctuary	________
ii) National Parks	________
iii) Biosphere Reserves	________
iv) Community Reserve	________

Answer:
i) Wildlife sanctuaries – Periyar
ii) National Park – Silent valley
iii) Biosphere reserves – Nilgiris
iv) Community reserves – Kadalaundi

Question 13.
Analyse the statement and answer the questions.
Specific cells seen at the tip of the stem and root in plants results in the growth of plants.
a) Identify the cells. (1)
b) Write down any two characteristics of these cells. (1)
Answer:
a) Meristematic cell
b) Cell wall is thinner, More amount of Cytoplasm, comparatively large nucleus (any two)

Answer any 2 questions from 14 to 17. Each carries 3 score. (3 × 2 = 6)

Question 14.
Ecological interactions and their examples are given in the boxes. Make pairs according to the model given below. (3)
Model – Predation: Deer and tiger

Ecological interactions	Examples
Predation	Mango tree and loranthus
Mutualism	Deer and tiger
Parasitism	Flower and butterfly
Commensalism	Mango tree and vanda Paddy and weeds

Answer:

• Mutualism : Flower and butterfly
• Parasitism : Mango tree and Loranthus
• Commensalism: Mango tree and Vanda

Question 15.
Write one function each from any 3 of the following cell organelles. (3)
a) Endoplasmic reticulum
b) Mitochondria
c) Ribosome
d) Vacuole
Answer:
a) Endoplasmic reticulum: Provides firmness and shape to the cell.
b) Mitochondria: Helps in the production and storage of energy.
c) Ribosome: Centre of protein synthesis.
d) Vacuole: Stores water, salts, excretory materials etc.

Question 16.
Arrange column B and C in accordance with column A (3)

A	B	C
Rearing of fish	Apiculture	Tussar
Rearing of honey bee	Pisciculture	White giant
Rearing of silkworm	Horticulture	Mellifera
	Sericulture	Rohu

Answer:

A	B	C
Rearing of fish	Pisciculture	Rohu
Rearing of honey bee	Apiculture	Mellifera
Rearing of silkworm	Sericulture	Tussar

Question 17.
Analyse the illustration and complete it. (3)

Answer:
A. xylem
B. Provides flexibility and support to plant parts.
C. Transports food synthesized in the leaves to various parts of the plant body.