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1C H A P TT EE SR T
1-06-2016
Contents
1. Motion ........................................................................................................................... 4
2. Force and Laws of Motion ...................................................................................... 5
3. Gravitation ................................................................................................................... 6
4. Matter in our surroundings .................................................................................. 7
5. Is Matter Around Us Pure ...................................................................................... 8
6. the Fundamental Unit of Life ............................................................................... 9
7. tissues ......................................................................................................................... 11
8. Improvement in Food Resources ........................................................................ 12
Practice Paper-1 ....................................................................................................... 14
Practice Paper-2 ....................................................................................................... 18
Practice Paper-3 ....................................................................................................... 23
Practice Paper-4 ....................................................................................................... 27
Practice Paper-5 ....................................................................................................... 31
SOLUTIONS TOChapTer TeST
4 – xs c i e n c e i
1. (a)
2. (c)
3. Speed is constant.
4. (a) When the velocity changes by equal amount in equal interval of time.
(b) When the velocity changes by unequal amount in equal interval of time.
5. Speed Velocity
1. Distance covered per unit time.
2. Speed has only magnitude, i.e., Scalar.
3. Speed is always positive.
1. Displacement covered per unit time.
2. It is a vector quantity.
3. It may be positive or negative.
6. u = 10 m/s, v = 25 m/s, t = 3 s
a = v u
t−
\ a = 25 10
3−
= 5 m/s2
7. a = 4 m/s2, s = ? t = 10 s, u = 0
v = u + at
\ v = 0 + 4 × 10 = 40 m/s
v2 – u2 = 2as
⇒ (40)2 – 0 = 2 × 4 × s
s = 40 40
8×
= 200 m.
8. Same as Ans 7.
9. u = 90 km/hr = 90 5
18×
= 25 m/s
a = – 0.5 m/s2, v = 0
s = ?
v2 – u2 = 2as
⇒ – (25)2 = 2 × – 0.5 × s
s = 25 252 0 5
6251
××
=.
= 625
1 Motion
5C H A P TT EE SR T
2 force and laws of Motion
1. (c)
2. (c)
3. Third law of motion.
4. Due to inertia of rest.
5. Dust particles continue to remain at rest due to inertia while carpet comes in a state of motion.
5. It carries a high forward momentum. In accordance with the law of conservation of momentum, the hosepipe experiences an equal momentum in backward direction. Thus, the hose tends to recoil backward.
7. F = ?, a = 16 m/s2, m = 250 g
F = m × a
= × 16 = 4 N.
8. m = 1500 kg, a = –1.7 m/s2, F = ?
F = m × a = 1500 × (–1.7) = –2550 N.
9. (a) Both vehicles experience same force of impact, due to action-reaction forces.
(b) Mass of truck is more, hence change in momentum of truck is more than change in momentum of car.
(c) Acceleration of car will have a greater magnitude because mass is less.
6 – xs c i e n c e i
1. (b) 2. (a) 3. The earth is attracted towards the moon, and is moving towards the moon. Since the mass
of earth is nearly 81 times of moon, the motion of earth is 181
th towards moon as compared
to motion of moon towards earth. So, the motion of earth is not commonly observed. 4. It explained several phenomena such as: (a) The force which binds us to the earth. (b) Motion of moon around the earth. (c) Motion of planets around the sun. (d) Occurrence of sea-tides due to attraction of moon and of sun. 5. The acceleration produced in a body on account of force of gravity is known as acceleration
due to gravity. It is denoted by ‘g’. 6. u = 0, h = 19.6 m, a = + g = 9.8 m/s2, v = ?
v2 – u2 = 2gh
v2 – 0 = 2 × 9.8 × 19.6
∴ v = = 19.6 m/s.
7. Take a sheet of paper and a stone. Drop them simultaneously from the first floor of abuilding. We observe that paper reaches the ground little later than the stone. This is due to air resistance. The air offers resistance due to friction to the motion of falling objects. The resistance offered by air to the paper is more than the resistance offered to the stone. If this experiment is performed in vacuum, they will fall at the same rate.
8. ME = 6 × 1024 kg, Ms = 2 × 1030 kg, d = 1.5 × 1011 m
F = GM M
dg s
2 = 6 67 10 2 10 6 10
1 5 10
11 30 24
11 2
.( . )
× × × × ××
−
∴ F = 3.56 × 1022 N.
9. (a) The force of gravitation between two bodies is directly proportional to the product of their masses and universly proportional to the square of the distance between them.
(b) Mass Weight
(i) It is measure of inertia of an object.
(ii) It is a scalar quantity.
(i) It is the force acting on the object due to gravity.
(ii) It is a vector quantity.
(c) M = 6 × 1024 kg, m = 1 kg , R = 6.4 × 106 m
F =
∴ F = 6 67 10 6 10 1
6 4 10
11 24
2 2
.( . )
× × × ××
−
= 9.8 N.
3 graVitation
7C H A P TT EE SR T
4 Matter in our surroundings
1. (d)
2. (a)
3. (b)
4. Sublimation
5. (a) gas
(b) solid
6. Because the molecules are tightly-packed like a lattice, the intermolecular space between the molecules is very less, and there is a strong electrostatic force of attraction between the molecules.
7. Acetone is a volatile liquid. It quickly vaporises as it is exposed to air. We know that evaporation is always followed by cooling. Hence, our palm feel cold.
8. We should wear light-coloured cotton clothes, since cotton is a good absorber of water, and light-colouredclothesreflectheat.
9. The latent heat is used up to overcome the forces of attraction between the particles of a substance during the change of state and it does not increase the kinetic energy of the substance.
10. Aim: To show diffusion becomes faster with increase in temperature.
Method:
1. Take a 100 ml beaker A and add 50 ml of cold water.
2. Take a 100 ml beaker B and add 50 ml of hot water.
3. Add equivalent amount of copper sulphate crystals to each beaker respectively and observe.
Observation:
(a) Copper sulphate crystals slowly dissolve and the solution turns blue in beaker B as compared to beaker A.
(b) The rate of diffusion is faster in beaker B due to increased temperature of water and also increased kinetic energy.
Result: The rate of diffusion is faster due to increase in temperature.
8 – xs c i e n c e i
5 is Matter around us Pure
1. (b) 2. (b) 3. (c) 4. (a) Melting of wax. (b) Glowing of an electric bulb. 5. They exhibit Tyndall effect.
6. Homogeneous mixtures Heterogeneous mixtures
(a) They have uniform composition throughout its mass.
(b) There is no visible boundary between the components.
(c) They are also known as solution, e.g., milk, petrol.
(a) They do not have uniform composition throughout its mass.
(b) There are visible boundaries of separation between its various constituents.
(c) They are not called solutions, e.g., soap solution, muddy water.
7. Air is considered as a mixture not a compound because: (a) It has variable composition. (b) The components of air retain their properties. (c) Components cannot be separated by chemical method, only by physical means, i.e.,
fractional distillation. (d)Nodefiniteboilingpoint. (e) No loss or gain in energy when oxygen and nitrogen are mixed.
8. Achemicalcompoundalwayscontainsthesameelementscombinedtogetherinthesamefixedratio by mass. For example, pure water obtained from any source, be it from river, well, ponds, it always contain the same elements. Hydrogen and oxygen combined together in the same fixedratiobymass.Thus,if9gofwaterisdecomposed,1gofhydrogenand8gofoxygenisobtained.
9. Mass of sugar (solute) = 30 g, Mass of water (solvent) = 370 g.
∴ Mass of solution = 370 + 30 = 400 g
∴ Concentration = × 100 = × 100 = 7.5%.
10. The two components of the given mixture are kerosene oil and water which can be separated by using separating funnel.
(a) Take a mixture of kerosene oil and water in a separating funnel. (b) Allow them to settle down. Oil forms an upper layer. (c) Open the stopcock and collect water into another beaker. (d) Stop the stopcock till all the water gets collected in another
beaker. (e) Oil remains behind in the separating funnel.
9C H A P TT EE SR T
6 the fundaMental unit of life
1. (b) 2. (c) 3. (b)
4. Cell wall is made up of cellulose but cell membrane is made up of proteins and lipids.
5. Ribosomes.
6. Deoxyribonucleic acid.
7. (a) The contents of the cell will shrink. (b) Exosmosis.
8. Camillo Golgi.
Functions:
1. Itstoresandmodifiestheproductsinvesicles. 2. It helps in packaging and dispatching of materials to the parts of the cell.
9. (b) Nucleus has chromatin material made up of DNA. DNA passes on features of the cell to the daughter cells with the help of its functional units called genes. It also controls the division of cell. It controls various chemical activities of the cell.
10. Prokaryotic Eukaryotic
1. Nuclearregionisnotwell-definedandis known as nucleoid.
2. It has single chromosome.
3. Membrane-bounded organelles are absent.
1. Nuclear region is well-defined and surrounded by nuclear membrane.
2. It has more than one chromosome.
3. Membrane-bounded organelles are present.
11.
(a) Mitochondrion
(b) Lysosome
MitochondrionLysosome
10 – xs c i e n c e i
(c) Plant cell Animal cell
1. It is bounded by cell wall and cell membrane.
2. It has plastids which provide colour (green or other).
1. It is bounded by only cell membrane.
2. It does not have plastids.
11C H A P TT EE SR T
7 tissues
1. (d)
2. (c)
3. (d)
4. Adipose tissue.
5. Located at the base of the leaves or internodes.
6. Simple tissue is made up of only one type of cells but complex tissue is made up of two or more types of cells.
7. (a) So as to prevent wear and tear. (b) To help in exchange of gases and carry on transpiration.
8. (a) Aerenchyma (b) Collenchyma.
9. The plant wilted as xylem tissue got blocked and leaves could not receive water.
10. (a) Striatedmusclefibres
(b) Unstriatedmusclefibres
Striatedmusclefibresarelong,cylindrical,branchedandmultinucleatewhereasunstriatedmusclefibresarelong,spindle-shaped,unbranchedanduninucleate.
11. (a) In brain, spinal cord and nerves. (b) Neuron/nerve cell.
(c)
12 – xs c i e n c e i
8 iMProVeMent in food resources
1. (c) 2. (d) 3. Barseem, Sudan grass. 4. Toprovidegreenmanure,theplantslikesunhemporguararegrowninthefieldandthen
mixed into the soil by ploughing them. These green plants mix in the soil and provide green manure.
5. Crop rotation. The crops selected for crop rotation should have different nutrient requirements. 6. The two groups of cattle feed are: (a) Roughage. Itislargelyfibre,lowinnutrientsandprovidebulktothefood. (b) Concentrate. Itislowinfibreandcontainsproteins,minerals,etc. 7. (a) Compositefishculturesystem. (b) Catlas as surface feeders, Rohus to feed in the middle zone and Mrigals and common carps
as bottom feeders. (c) The main advantage is that all the food available in pond, is consumed without any
competition.Italsoincreasesthefishyieldfromthepond. 8. (a) Biotic and abiotic factors. Biotic factors are insects, rodents, fungi, mites and bacteria
whereas abiotic factors are inappropriate moisture and temperature at the place of storage. (b) The grains affected by above factors show following features: (i) Degraded quality (ii) Loss in weight (iii) Discolouration (iv) Poor germinability.
9. (a) Weeds (b) (i) They compete for food, space and light with crop plants. (ii) They spread plant diseases. (c) They can be removed by: (i) Manual uprooting by using Khurpi or weeder.
(ii) By spraying weedicides.
SOLUTIONS TO
PRACTICE PAPERS
14 – XS C I E N C E I
1. Solid 2. a = 9.8 m/s2
3. Mitochondria.
4. The cells shrink due to loss of water by the cells.
5. (a) Adipose tissue. (b) Squamous epithelial tissue.
6. The blanket is initially in a state of rest. On beating with a stick, the blanket comes in a state of motion. But dust present in it tends to remain in rest due to inertia of rest and hence, comes out of the blanket.
7. Manure are better than fertilizers in following ways:
(i) Manures add organic matter to the soil so as to increase its water holding capacity.
(ii) Manures do not change the chemical nature of the soil.
(iii) Manures are obtained from natural materials so are inexpensive.
8. (a) The farming practice which involves minimum or no use of chemicals as fertilizers, pesticides, etc., but maximum use of organic manures and biowastes.
(b) (i) Farm wastes and culture of blue-green algae.
(ii) Neem leaves and turmeric.
9. (a)Duringsummer,waterkeptinanearthenpotcontinuestoevaporatethroughfineholesof it. Since evaporation causes cooling, water kept in an earthen pot becomes cool during summer.
(b) Sponge contains tiny pores in which air/water seeps in. When it is compressed, the air squeezes out.
(c) At 273 K, ice can absorb more amount of heat than water due to latent heat of fusion. Hence, ice at 273 K can cause more cooling.
10. (a) Chromatography.
(b) By using separating funnel.
(c) Acetone and water. 11.
Nucleoid
Cytoplasm
Ribosomes
CiliaCell wall
Cell membrane
Example: bacterium.
PRACTICE PAPER-1
15p r a c t i c e p a p e r s
12. Lysosomes They are capable of breaking down all organic material and keep the cell clear by digesting
worn out cell organelles. Theyaremembrane-boundsacsfilledwithpowerfuldigestiveenzymes. When the cell is worn out and needs to be destroyed, the lysosomes burst and the enzymes
digest the cell.
13. Unstriatedmusclefibre.
14. (a) Engine of a moving train applies brakes so as to stop the train.
(b) Acceleration of a freely falling body.
(c)Accelerationofaflyingbird.
15. Take a spherical rubber ball and apply force on both sides by pressing with your hands. The ball becomes elongated. It shows that shape of ball has changed due to external force.
16. m1 = 3 kg, a = 6 m/s2 m2 = 4 kg, a2 = 4 m/s2
∴ F1 = m1 × a1 F2 = m2 × a2
= 3 × 6 = 18 N = 4 × 4 = 16 N
∴ F1 > F2.
17. The force of gravitation between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
i.e.,
m1
m2
d
18. Take a long hollow glass tube A, at least 1 m in length and 4.5 cm in diameter. The tube has adjustable covers on both sides. P is an arrangement to let a feather and a gold coin fall.
Initially, using a vacuum pump air, from inside the tube is sucked out and then the tube is closed so that it becomes air tight. Push the platform P suddenly outward, so that feather as well as gold coin both start
16 – xs c i e n c e i
falling vertically downward under gravity. Careful observations showed that both the objects reach the bottom of the tube at the same instant. It proves that motion of all freely falling bodies are exactly identical.
19. (a) Mixed cropping is growing of two or more crops simultaneously on the same piece of land, e.g., wheat + gram, wheat + mustard. Intercropping is growing of two or more crops in the samefieldinadefinitepattern,i.e., alternating rows of crop plants, e.g., soyabean + maize.
(b) Crop rotation is growing of two different crops in a piece of land in a preplanned succession, e.g., growing of a cereal crop and a legume crop alternating with each other.
Advantages: (i)Ithelpsinmakingupthedeficiencyofnutrients. (ii) More than two crops can be grown in a year with good harvest. 20. By distillation.
(a) Takethemisciblemixtureofalcoholandwaterinadistillationflask. (b) Fit it with a thermometer. (c) Arrange the apparatus. (d) Heat the mixture gently noticing the temperature in the thermometer. Observation Alcoholhavinglowboilingpointvaporisesfirst.Itcondensesinthecondenserandiscollected
in the receiver. (e)Waterisleftbehindinthedistillationflask.
21. (a) Sponge contains tiny pores in which air/water seeps in. When it is compressed, the air squeezes out.
(b) Because the heat energy supplied is used in changing the state (melting and boiling) by overcoming the forces of attraction between the particles. This energy is hidden and is known as latent heat. Hence temperature remains constant during change of state.
(c) Vaporisation is a surface phenomenon and can occur even below boiling point. Whereas boiling is a bulk phenomenon in which the particles have to gain enough kinetic energy to get converted into gaseous state.
22. (a) Momentumofabodyisdefinedastheproductofitsmassandvelocity.Itsunitiskgm/sInitial momentum = mv = 50 × 4 = 200 kg m/s
17p r a c t i c e p a p e r s
(b) Final momentum = mv = 50 × 8 = 400 kg m/s
\ Force = mv mu
t−
=−400 2008
= 25 N.
23. (i) Uniform accelerated motion (ii) Acceleration of the object (iii) Distance travelled by the object.
(iv) Distance = area of right angled triangle ODC = 12
b × h = 12
(15) × 30 = 225 m.
24. (a) Bloodisafluid(liquid)thatflowsthroughoutthebodyandthusconnectsthedifferentparts of body. So, blood is called connective tissue.
(b) Blood transports, nutrients, hormones and vitamins. (c) By donating blood one can save the life of a needy person/patient. 25. (a) 26. (c) 27. (c) 28. (b) 29. (b) 30. (a)
31. (a) 32. (b) 33. (d) 34. The blue colour of the solution turns green due to the formation of FeSO4 and reddish brown
copper metal gets deposited. Fe + CuSO4 → FeSO4 + Cu (blue) (green) 35. The magnitude of force required to move a block lying on a horizontal table mainly depends
on two factors—(i) mass and size of the wooden block and (ii) surface of block and table in contact. So frictional force between block and table would be different in the experimental set-ups of each student.
36. (i) The cell body has single nucleus (ii) The cell body gives one or many small braches called dendrites. (iii) The cell body has a single long axon. It may have a myelin sheath or may not have in
some. (iv) It is the longest cell present in body.
18 – xs c i e n c e i
1. Solid
2. 0 (zero)
3. Movement of water from its higher concentration to its lower concentration through a semipermeable membrane is called osmosis.
4. By Tyndall effect, when a beam of light is passed through the colloidal solution kept in dark, the path of light becomes visible.
5. It has many layers of cells. It protects the inner tissues from infections and damage.
6. The force of gravitation between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
i.e.,
m1
m2
d
7. (a) Cell wall is made up of cellulose but cell membrane is made up of proteins and lipids. Cellwallgivesfixedshapetotheplantcellbutcellmembranecontrolsentryandexitofsubstances.
(b) Amoeba takes in food by endocytosis.
8. Duration of light period and dark period is called photoperiod. It affects growth of plants and flowering.
9. (a) Solid (b) Solid (c) Gas
10. Homogeneous mixture Heterogeneous mixture
•Uniformcompositionthroughoutitsmass.
•Novisibleboundariesofseparationbetween the constituents.
•Doesnothaveauniformcompositionthroughout its mass.
•Visibleboundariesofseparationbetweenthe constituents.
(a) Homogeneous (b) Heterogeneous
(c) Homogeneous (d) Homogeneous
11. Three types of plastids are:
1. Chloroplasts. They contain chlorophyll, so they are the site of photosynthesis.
2. Chromoplasts. They contain other coloured pigments, so they provide different colours to flowersandfruits.
3. Leucoplasts. They are colourless and store oil, starch and other food materials.
PRACTICE PAPER-2
19p r a c t i c e p a p e r s
12.
13. (a) Inthissystem,acombinationoffiveorsixfishspeciesarerearedinasinglefishpond.They are selected on the basis of their feeding habit.
(b) Advantage. Theyconsumeallthefoodavailableinthepondsofishyieldincreases.
Drawback. Mostoffishspeciesbreedduringmonsoonsofishseedismixedup.
14.
15. It is based on third law of motion. As the water comes out of the nozzle of the sprinkler, an equal and opposite reaction force comes into play. So, the sprinkler starts rotating.
16. We know, g = or M =
or Density (D) = (Here, VE = volume of the earth)
∴ D =
17. m = 100 kg; u = 5 m/s; v = 8 m/s; t = 6 s
∴ Initial momentum p1 = mu = 100 × 5 = 500 kg m/s
Final momentum p2 = mv = 100 × 8 = 800 kg m/s
∴ Force exerted =
F =
18. Buoyant force = weight of the liquid displaced
= density of water × volume of water displaced × g
= 1000 ×
20 – xs c i e n c e i
19. (a) Crop varieties are improved by hybridisation. It means crossing two different varieties/ species/genera to obtain desirable varieties.
(b) Three factors: 1. To increase the overall yield per acre of the crop. 2. To improve quality of the crop, e.g., protein quality in pulses, oil quality
in oil seeds. 3. To shorten the maturity duration of the crop.
20. (a) Government should regulate production and supply of such medicines. There should be a proper law for sale and purchase of such medicines.
(b) Mass of glucose (solute) = 40 g Mass of water and alcohol (solvent) = 400 – 40 = 360 g
Concentration = × 100 = 11.11%
21. Napthalene is insoluble in water but soluble in ether (organic solvent). Ammonium chloride is soluble in water. It decomposes on heating to drayness.
22. (a) Newton’s second law of motion, F = m × a ∴ F = mg
or Universal law of gravitation (F) = ; ∴ mg = or g = .
(b) gE = g, gM = g/6; F = mgE = 15gE newton
Now, mass lifted by the same force on the moon
m = F
gg
gM
=15
6/= 90 kg.
23. The sum of momentum of the two objects before collision is equal to the sum of momentum of the collision. Provided there is no external unbalanced force acting on them.
m1 v1 = m2 v2 Whenapersonfallsonthehardfloor,heisbroughttorestinaveryshortintervaloftimeso
greater force comes into play. When he falls on a heap of sand, he is brought to rest in a longer time, so lesser force is comes into
play.
21p r a c t i c e p a p e r s
24. All cells vary in their shape, size and activities and have three major functional regions, viz., plasma membrane, nucleus and cytoplasm.
Plasma Membrane or Cell Membrane: This is the outermost covering of the cell that separates the contents of the cell from its external environment. Plasma membrane is a living, thin, delicate, elastic, selectively permeable membrane made up of proteins and lipids and is present in both plant and animal cells.
Functions of plasma membrane:
(i)Itgivesdefiniteshapetothecell. (ii) It separates the contents of a cell from its surrounding medium. (iii) It provides mechanical barrier for the protection of the internal contents of the cell. (iv) It is selectively permeable membrane. (v) It regulates the movement of ions in and out of the cell. Nucleus: Robert Brown in 1831 discovered the nucleus in the cell. Nucleus is the largest cell
structure. It is a spherical or oval prominent structure usually located in the centre of the cell. Nucleus has the following important parts:
(i) Nuclear membrane: It is a double layered membrane, which separates nucleus from the cytoplasm. It has pores called nuclear pores which allow the transfer of material from inside the nucleus to the cytoplasm.
(ii) Nucleoplasm: Itisahomogeneousandgranulardensefluidpresentinsidethenucleus,in which chromatin and nucleolus are suspended.
(iii) Chromatic material: It consists of long, coiled network of thread-like structures. The chromatin material is made up of deoxyribonucleic acid (DNA) which is responsible for storing and transmitting the hereditary information from one generation to the other. It condenses into compact rod-like bodies called chromosomes at the time of cell division.
(iv) Nucleolus: It is more or less round structure found inside the nucleus. The nucleolus contains RNA (ribonucleic acid) and proteins. RNA is helpful in protein synthesis in the cytoplasm.
22 – xs c i e n c e i
Functions of nucleus:
(i) The nucleus controls all metabolic activities of the cell.
(ii) It regulates the cell cycle.
(iii) It is concerned with the transmission of hereditary traits from the parent to offspring.
Cytoplasm: It is the fluid content of the cell which occurs between the plasma membrane and the nuclear envelope. It contains various cell organelles which perform different functions of the cell.
Functions of cytoplasm: (i) Cytoplasm helps in exchange of materials between cell organelles. (ii) It acts as a store of vital chemicals such as amino acids, glucose, vitamins, ions, etc. (iii) It is the site of certain metabolic pathways such as glycolysis. Synthesis of fatty acids,
nucleotides and some amino acids also take place in the cytoplasm 25. (c) 26. (b) 27. (b) 28. (c) 29. (c) 30. (b)
31. (c) 32. (c) 33. (c)
34. (a) Test tube A – Salt solution – True solution. Test tube B – Starch solution – Colloidal solution Test tube C – Sand in water – Suspension (b) Solution in test tube C can undergo filtration.
35. Following precautions should be taken: 1. The pulley should be made smooth with oiling. 2. The horizontal surface should be cleaned. 3. The pan and the spring balance should not touch the wall or any surface. 4. Weight in the pan should be increased.
36.
Epidermis
Sclerenchyma
Parenchyma
Pith
23p r a c t i c e p a p e r s
1. Evaporation.
2. Uniform motion.
3. Smooth endoplasmic reticulum.
4. (a) Fusion
(b) Sublimation.
5. Lysosomes contain powerful digestive enzymes which can break down all organic materials. When a cell is damaged, the lysosomes burst and these enzymes digest the contents of its own cell. So, they are called suicidal bags.
6. Steel, since it has greater density and greatest mass, therefore, it has highest inertia.
7. (a) In bones. Bone cells are embedded in a hard matrix having compounds of calcium and phosphorus.
In cartilage. The cells are embedded in the solid matrix made up of proteins and sugars.
(b) Xylem tissue has dead cells and transports water. Phloem tissue has living cells and transports food.
(c) Bloodisredduetothepresenceofredbloodcells.Lymphisapalefluidasitdoesnothave red blood cells.
8. (a) High honey collection capacity
(b) Do not sting
(c) Stay in a beehive for long periods
(d) Breed quite well
Italian bees have all the above features.
9. (a) Spreading of virus on sneezing.
(b) Spreading of smell of cake being baked in the house.
(c) Aquatic animals using oxygen dissolved in water.
10. (a) Separating funnel, e.g., kerosene oil and water.
(b) Sublimation, e.g., camphor and salt.
11. Parenchyma Collenchyma Sclerenchyma
• Thickness of the wall
• Function
• They have thin cell wall made up of cellulose.
• They help in manu-facturing and storing of food.
• They have cell wall thickened only in the corners.
• They provide mechan-ical support as well as manufacture food.
• They have very thick cell wall due to deposition of lignin.
• T h e y p r o v i d e mechanical support to hard and strong parts of plant.
PRACTICE PAPER-3
24 – xs c i e n c e i
12. Eukaryotic cell Prokaryotic cell
•Nuclearregioniswell-defined •Nuclearregionisnotwell-definedand and is surrounded by nuclear membrane. is not surrounded by nuclear membrane. • It has more than one chromosome. • It has single chromosome.
• Membrane-bound organelles are present. • Membrane-bound organelles are absent. 13. (a) Composite fish culture system is amethod of intensive fish farming. In this system a
combinationoffiveorsixfishspeciesisusedinasinglefishpond. (b) Inthissystemsuchfishareculturedthatdonotcompeteforfoodamongthem,e.g., catla,
rohus, mrigals, etc. (c) Advantages: (i)Alargevarietyoffishcanbeculturedinasinglefishpond. (ii)Allthefoodavailableisconsumedbythefishfromthepondwithout
any competition. Disadvantage: (i)Thefishseedsgetmixedbecauseallthefishbreedinthesameseason.
14. Thedistancetravelledinfirst8second,x1 = 0 + (5)(8)2 = 160 m. At this point, v = u + at
= 0 + 5 × 8 = 40 m/s
Distance covered in last 4 seconds x2 = (40 × 4) = 160 m.
∴ Total distance (x) = x1 + x2
= 160 + 160 = 320 m.
15. From graph, u = 80 m/s, v = 0, t = 8 s
(i) Acceleration (a) = = – 10 m/s2
(ii) Frictional force (F) = m × a = × (–10) = – 5 N.
16. Totalmomentumbeforefiring=0
= 0.02 kg × 100 + 1.5 × v = 2 + 1.5v m/s ∴Totalmomentumafterfiring=totalmomentumbeforefiring. 2 + 1.5 v = 0
or v =
Negative sign indicates that the direction of recoil of pistol in opposite to that of bullet.
17. (a) At the equator (b) No, though the moving object comes back to its initial position, the distance travelled is
not zero.
18. (a) g = where M = mass of the earth, R = radius of the earth. (b) The blanket is initially in a state of rest. On heating with a stick, the blanket comes in a state
of motion. But dust present in it tends to remain in rest due to inertia of rest and hence, comes out of the blanket.
25p r a c t i c e p a p e r s
19. (a) Storage grains get damaged due to following factors:
(i) Biotic factors—insects, fungi, rodents, mites, birds and bacteria.
(ii) Abiotic factors–inappropriate moisture and temperature in the place of storage, etc.
(b) Preventive measures before storing grains are as follows:
(i) Drying the grains.
(ii) Proper cleanliness and hygiene of the container and storage place.
(iii) Prophylatic treatment.
(iv) Improved storage structure.
(c) Government agencies lack responsibility/accountability and concern for poor or needy people.
20. (a) Ironfilingsareseparatedbyusingabarmagnet. (b) Ammonium chloride is separated by the process of sublimation. (c) Sandisseparatedfromsodiumchloridebytheprocessoffiltration. 21. (a) Acetone is volatile and vaporises quickly. (b) Cotton clothes should be worn in summer because cotton is a good absorber of water and
evaporates quickly leaving us cool.
(c) The particles are held together by a strong force of attraction.
22. h1 = h2 = as u = 0 tt
hh
1
2
1
2
= .
The ratio of the time shall remain the same if (a) One of the object is hollow and the other one is solid—as the ratio does not depend on
masses. (b) Both the objects are hollow as acceleration due to gravity (g) is independent of mass and
whether the body hollow or solid also. As size remains the same there is no effect of resistance due to air in the two cases.
23. (a) v = 12 m/s, t = 2 s, v = 18 m/s, t = 4 s
v = u + at
⇒ 12 = u + 2a ...(i)
After 4 s, 18 = u + 4a ...(ii)
⇒ 6 = 2a
or a = 3 m/s2
or 12 = u + 6
∴ u = 6 m/s.
(b ) Forces which balance one another and the net force acting on the object is zero. Consider a wooden block ‘A’ placed on a horizontal table surface. Let us apply forces F1 and F2 on the block in mutually opposite directions, so that the block does not move from its rest position. Hence, the net effect of F1 and F2 taken together is zero. Thus, F1 and F2 are balancing each other.
26 – XS C I E N C E I
24. (a)Ribosomes
Cell wall
NucleoidA Prokaryotic cell
Plasma membrane
(b) Differences:
Prokaryotic cell Eukaryotic cell
• Sizeofthecellisgenerally • Sizeofthecellisgenerallylarge small (1–10 µm). (50 –100 µm). •Nuclearregionispoorlydefineddue •Nuclearregioniswell-definedand to absence of nuclear membrane and surrounded by a nuclear membrane. known as nucleoid.
25. (a) 26. (b) 27. (c) 28. (b) 29. (b) 30. (a)
31. (b) 32. (a) 33. (c) 34. An insoluble substance formed in the solution is called a precipitate. When the product
formed is not soluble, it is clearly visible. 35. (a) We use massless string and smooth pulley to get accurate measure of the force required
to move the block. (b) If the string used in the experiment is not massless, the reading of the spring balance
will be more than the actual force required to move the block. 36.
Cell walls lignifi ed
Pit
Empty lumen
Cell walls lignifi ed
Pit
Empty lumen
27p r a c t i c e p a p e r s
1. Air, oil, sugar increasing order.
2. They help in storing and packaging of various cellular sections.
3. It will go to a maximum height h.
4. (a) Iodine
(b) Graphite.
5. (i) Provide surface for biochemical reactions.
(ii) Help in manufacturing fats or lipids.
6. The total quantity of motion contained in an object is called its momentum. Mathematically, it is momentum (p) = mass (m) × velocity (v)
⇒ Fp p
t
m v u
tma∝
−∝
−∝2 1 ( )
a = v u
t−
7. For making green manure, some plants like sun hemp or guar are grown and then mixed in the soil by ploughing on them. These leguminous plants form green manure.
8. (a) The tiny pores are stomata.
(b) They perform two functions:
(i) Exchange of gases between the leaf and atmosphere.
(ii) Transpiration, i.e., loss of water in the form of vapours.
9. The temperature of both boiling water and steam is 100°C, but steam has more energy because of latent heat of vaporisation.
10. Both fog and smoke have gas as the dispersion medium. The only difference is that the dispersed phase in fog is liquid and in smokes, it is a solid.
11.
12. The nucleus is bounded by a double and porous nuclear membrane. The pores allow transfer of materials from inside the nucleus to its outside. Nucleus contains a network of thread-like structurescalledchromatinwhichismadeupofDNA.Chromatinchangesintoafixednumber
PRACTICE PAPER-4
28 – xs c i e n c e i
of chromosomes during cell division. Nucleus contains nucleolus made up of RNA. It also contains nucleoplasm.
13. Insect pests may attack crop plants in following three ways: (a) They cut the root, stem and leaf. (b) They suck the cell sap from various parts of the plant. (c) They bore into stem and fruit. 14. (a) Since velocity is not changing, acceleration is equal to zero.
(b) Velocity = 20 m/s.
(c) Distance s = ut = 20 × 15 = 300 m. 15. (a) The rate of change of momentum of an object is proportional to the applied unbalanced
force in the direction of the force. (b) m = 800 kg, u = 20 m/s, v = 0, s = 8 m
a = v u
s
2 2 2
20 20
2 8−
=−
×( )
= = – 25 m/s2
F = ma = 800 × – 25 = – 20000 N.
16. Both stones will take the same time to reach the ground because the two stones fall from the same height.
17. u = 0, t = 4 s, g = 10 m/s2, h = ?
s = ut + 12
gt 2
h = 012
10 4 2+ × ( ) = 80 m
18. A ship has a larger volume as compared to the solid sheet of the same mass. Accordingly a part of ship displaces more water than the entire solid sheet and thus experiences more buoyant force and does not sink.
As we know
Average Density =
Since the volume of the ship is much more than that of solid sheet of the same mass, average densityoftheshipislessthanthatofwater.Hencetheshipfloatsandsheetsinks(becauseitsaverage density is more than water).
29p r a c t i c e p a p e r s
19. (a) Weeds are the unwanted plants that grow along with the crop plants. (b) Parthenium, Amaranthus (c) They absorb nutrients and water from the soil and reduce the yield of the crop. (d) (i) By manually uprooting them. (ii) By using weedicides . 20. (a) Mass of solute (sodium sulphate) = x g
Mass % = 10% Given, Mass of water = 100 g Mass of solution = 100 + xg
⇒ % of sodium sulphate =
or × 100 = 10
or = 10
∴ x = 11.11
(b) Physical change Chemical change
(a) It is a temporary change. (a) It is a permanent change. (b) No new substance is formed. (b) New substance is formed. (c) The change is reversible. (c) The change is irreversible.
(d) No energy change. (d) Energy change is involved.
Burning of candle. Eating of chocolate. 21. (a) Because the particles absorb heat energy from the surroundings leaving the surrounding
cool. Hence, evaporation is always followed by cooling. (b) (i) Chemical change (ii) Physical change (iii) Change.
22. F ∝ m1 m2
F ∝
This hypothesis is not correct. The two bricks like a single body, fall with the same speed to reach the ground at the same time in case of free fall. This is because acceleration due to gravity is independent of the mass of the falling body.
23. (a) Given v = 0, a = – 4 m/s2, t = 3 seconds, u = ? v = u + at 0 = u + (– 4 × 3) ∴ u = 12 m/s Intitial speed of the car = 12 m/s = 43.2 km/h
(b) s = ut +12
at2
= 12 × 3 + 12
× – 4 × (3)2 = 36 – 18
∴ s = 18 m
30 – xs c i e n c e i
The old man is 20 m away from the car, when brake is applied. The car travels a distance 18 m before coming to rest. Hence the driver would succeed to save the old man.
(c) Concern for other’s safety/lives.
24. (a)
Transverse section of Collenchyma tissue
(b) Differences:
Parenchyma Collenchyma
(i) Living cells, isodiametric in shape. (i) Living cells, cells with thick corners. (ii) Cell walls are thin and made up (ii) Cell walls are thickened at corners of cellulose. with extra deposition of cellulose and pectin.
25. (b) 26. (a) 27. (d) 28. (b) 29. (c) 30. (a)
31. (a) 32. (a) 33. (a)
34. Sand–Byfiltration Ammonium chloride – By sublimation Ironfilings–Byamagnet. 35. (a) The tension in the connecting string increases. (b) As smaller the steps in which the weights are increased in pan, the observation and the
measure of the force is accurate. 36. Location: These cells are found in stems, leaves, roots, fruits and other soft tissues.
Functions: It helps in photosynthesis, stores food, etc.
31p r a c t i c e p a p e r s
1. Sublimation.
2. Uniform acceleration.
3. Ribosomes.
4. (a) Sublimation (b) Freezing
5. Genes are located on the chromosomes. They help in inheritance of characters.
6. To increase the area (A) and decrease the pressure (P), due to weight (F) of the train moving
the rail (P = FA
). This prevents the train sinking into ground.
7. Macronutrients are required in large quantity for growth and development of the plant, e.g., nitrogen, from soil, oxygen from water.
8. The solution that has lower concentration of solute, then the cell is hypotonic. The contents of the cell will swell up when the cell is placed in hypotonic solution. More water molecules move in by osmosis.
9. Conditions that increase the rate of evaporation are: (a) An increase in surface area by spreading the shirt. (b) An increase in temperature by putting the shirt under the sun. (c) An increase of wind speed by spreading it under the fan.
10. (a) Acetone and water by distillation.
(b) Chromatography (dyes present in ink).
11. The constituents of phloem tissue are:
(a) Sieve tubes (b) Companion cells (c) Phloem parenchyma (d)Phloemfibres.
Its function is translocation of food.
12. (a) Indian breed. Aseel
Foreign breed. Leghorn
(b) Two reasons for variety improvement of poultry are:
(i) To increase the number and quality of chicks.
(ii) To obtain dwarf broiler parent for commercial chick production.
13. (a) Three types of epithelium tissues are–squamous epithelium, cuboidal epithelium and columnar epithelium.
(b) The difference between them are: (i) Squamous epithelium. Ithasthinandflatcellswithnucleusinthecentre. (ii) Cuboidal epithelium. It has cube-like cells and nucleus lies in the centre. (iii) Columnar epithelium. It has tall column-like cells with nucleus towards the base.
PRACTICE PAPER-5
32 – xs c i e n c e i
14. F = 0.6 N, u = 5 m/s, v = 6 m/s, t = 2 s, m =?
a = v u
t−
= 12
= 0.5
F = m × a
∴ m = Fa
=0 60 5..
= 1.2 kg.
15. u = 40 km/h, v = 50 km/h, a = ?, t = 2 minutes (10.00 a.m to 10.02 a.m)
a = v u
t−
=−×
50 402 60
= 10 5
18120
×
= 50
18 120× = 0.023 m/s2.
16. u = 29.4 m/s, h = ?, t = 1 s
v2 – u2 = 2 as
0 – (29.4)2 = 2 × (9.8) s
∴ s = 29 4 29 4
2 9 8. .
.×
× = 45.1 m.
(a) s = ut +12
gt2
⇒ s = 29. 4 × 1 +12
× 10 × 1
or = 29.4 + 5 ∴ s = 34.4 m.
(b) s = ut + gt2
s = 29. 4 × 2 + × 10 ×(2)2
= 58.8 + 5 × 4 = 58.8 + 20 = 78.8 m.
17. (i) B has greater inertia. (ii) Momentum of ball A, pA = m.(2v) = 2mv Momentum of ball B, pB = (2m).v = 2mv Hence pA = pB
( iii) Force needed to stop ball A,
FA =
Force needed to stop ball B
FB =
33p r a c t i c e p a p e r s
FA: FB =
2
2
mvtmvt
= 1:1
18. According to Newton’s second law of motion, the rate of change of momentum of an object is directly proportional to the applied unbalanced force on it and is in the direction of force.
i.e., F ∝
⇒ ∝
∴ F ∝ ma .
19. (a) Weeds harm the crop plants:
(i) They compete for food, space and light thus affect the growth of the plant.
(ii) They reduce the yield of the crop.
(iii) They sometimes act as hosts for disease-causing organisms and spread diseases.
(b) Weeds can be controlled by:
(i) Mechanically uprooting them.
(ii) Using weedicides.
(iii) Summer ploughing and crop rotation.
20. (a) Milk solution is a colloid and would show Tyndall effect.
(b) Salt solution is a true solution and would not scatter light.
(c) Detergent solution, sulphur solution.
21. (a) (i) Tyndall effect
(ii) Diffusion
(b) (i) Sugar crystals are separated by the method of crystallisation.
(ii) Compound iron sulphide is formed.
(iii) Volatility since perfume is volatile.
22. The time taken by the ball A to reach the ground is given by s = ut + gt2
or 44.1 = × (9.8) × t2
or t2 =
∴ t = = 3 s.
Suppose the ball B was thrown with initial speed u. It was thrown 2 s after A was dropped and it reached the ground together with A. So, the total time for which it has fallen is (3 – 2 = 1 sec).
s = ut + gt2
34 – xs c i e n c e i
44.1 = u × 1 + (9.8) × (1)2
44.1 = u + 4.9
or u = 44.1 – 4.9
∴ u = 39.2 m/s.
23. (a) From Stop B tyo Stop C:
Speed of the bus = 60 km/h
Time = 6 minutes = 660
= 0.1 h
∴ Distance = Speed × Time
= 60 × 0.1 = 6 km (b)
10 km 6 km 12 km
50 km/h 60 km/h x km/hA
B C
D
From Stop A to Stop B:
Distance = 10 km
Speed = 50 km/h
Time = hours
From Stop B to Stop C:
Distance = 6 km
Time = minutes = hours From Stop C to Stop D: Distance = 12 km Let speed = x km/h
∴ Time =
Average speed =
or 40 = 10 6 1215
110
12+ +
+ +x
or 40 =
∴ x = 30 km/h Speed of the bus between stops C and D = 30 km/h. (c) The passenger shows concern for the safety of himself and others, and adherence to the
rule of law.
35p r a c t i c e p a p e r s
24. Muscle present in heart is cardiac muscles and that present in limbs is voluntary or striated muscles.
Differences:
Striated muscles Cardiac muscles
(i) It is arranged in bundles. (i) It is arranged as a network. (ii) Its ends are blunt. (ii) Itsendsareflatandzig-zag.
25. (c) 26. (a) 27. (c) 28. (b) 29. (b) 30. (b)
31. (d) 32. (d) 33. (d)
34. (a) Assoonasthemixtureofironfilingsandsulphurisheated,itbecomesblackandahardmass is formed. A new compound is formed which is iron sulphide.
(b) It can be separated by chemical reaction. 35. The reading of spring balance will be zero. When the block is just about to move, the force
by which spring is pulled is equal to the frictional force between block and the surface on which it is placed. So spring balance shows zero reading.
36.
