Brain Grain · braingrain.in
Science — Practice Paper · Set 1
Class: 7CBSE / NCERTMax Marks: 34
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.Choose the correct option from the following: Plants take carbon dioxide from the atmosphere mainly through their: (i) roots (ii) stem (iii) flowers (iv) leavesa. rootb. stemc. leafd. flower[1]
2.One litre of water at 30 °C is mixed with one litre of water at 50 °C. The temperature of the mixture will be (a) 80 °C (b) more than 50 °C but less than 80 °C (c) 20 °C (d) between 30 °C and 50 °Ca. 80 °Cb. more than 50 °C but less than 80 °Cc. 20 °Cd. between 30 °C and 50 °C[1]
3.A wooden spoon is dipped in a cup of ice cream. Its other end (a) becomes cold by the process of conduction. (b) becomes cold by the process of convection. (c) becomes cold by the process of radiation. (d) does not become cold.a. becomes cold by the process of conductionb. becomes cold by the process of convectionc. becomes cold by the process of radiationd. does not become cold[1]
4.Which of the following is not a forest product? (i) Gum (ii) Plywood (iii) Sealing wax (iv) Kerosenea. gumb. plywoodc. sealing waxd. kerosene[1]
5.An electric iron of 1 kW is operated at 220 V. Which of the following fuses should be used in the circuit? (i) 1 A (ii) 3 A (iii) 5 A (iv) 13 Aa. 1 Ab. 3 Ac. 5 Ad. all of these[1]
6.Tick the correct answer: (a) In cockroaches, air enters the body through (i) lungs (ii) gills (iii) spiracles (iv) skin (b) During heavy exercise, we get cramps in the legs due to the accumulation of (i) carbon dioxide (ii) lactic acid (iii) alcohol (iv) water (c) Normal range of breathing rate per minute in an average adult person at rest is (i) 9-12 (ii) 15-18 (iii) 21-24 (iv) 30-33 (d) During exhalation, the ribs (i) move outwards (ii) move downwards (iii) move upwards (iv) do not move at alla. lungs / gills / spiracles / skinb. CO2 / lactic acid / alcohol / waterc. 9-12 / 15-18 / 21-24 / 30-33d. outwards / downwards / upwards / no movement[1]
7.An iron ball at 40 °C is dropped in a mug containing water at 40 °C. The heat will (a) flow from iron ball to water. (b) not flow from iron ball to water or from water to iron ball. (c) flow from water to iron ball. (d) increase the temperature of both.a. flow from iron ball to waterb. not flow from iron ball to water or from water to iron ballc. flow from water to iron balld. increase the temperature of both[1]
8.Which of the following statements is not correct? (i) Forests protect the soil. (ii) In forests, plants and animals depend on one another. (iii) Forests have no influence on climate. (iv) Soil helps forests to grow and regenerate.a. Forests protect the soil from erosion.b. Plants and animals in a forest are not dependent on one another.c. Forests influence climate, water cycle and air quality.d. Soil helps forests to grow and regenerate.[1]
9.Tick the correct answer: (a) The reproductive part of a plant is the (i) leaf (ii) stem (iii) root (iv) flower (b) The process of fusion of the male and the female gametes is called (i) fertilisation (ii) pollination (iii) reproduction (iv) seed formation (c) Mature ovary forms the (i) seed (ii) stamen (iii) pistil (iv) fruit (d) A spore producing organism is (i) rose (ii) bread mould (iii) potato (iv) ginger (e) Bryophyllum can reproduce by its (i) stem (ii) leaves (iii) roots (iv) flowera. leaf / stem / root / flowerb. fertilisation / pollination / reproduction / seed formationc. seed / stamen / pistil / fruitd. rose / bread mould / potato / gingere. stem / leaves / roots / flower[1]
10.A virtual image larger than the object can be produced by a (i) concave lens (ii) concave mirror (iii) convex mirror (iv) plane mirrora. concave lensb. concave mirrorc. convex mirrord. plane mirror[1]
Part II — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
11.How would you test the presence of starch in leaves?[2]
12.What is a virtual image? Give one situation where a virtual image is formed.[2]
13.Match structures given in Column I with functions given in Column II: Column I: Stomata, Xylem, Root hairs, Phloem. Column II: Absorption of water, Transpiration, Transport of food, Transport of water.[2]
14.Fill in the blanks: (a) The hotness of an object is determined by its __________. (b) Temperature of boiling water cannot be measured by a __________ thermometer. (c) Temperature is measured in degree __________. (d) No medium is required for transfer of heat by the process of __________. (e) A cold steel spoon is dipped in a cup of hot milk. It transfers heat to its other end by the process of __________. (f) Clothes of __________ colours absorb heat better than clothes of light colours.[2]
15.Match the following: Column I: Land breeze blows during, Sea breeze blows during, Dark coloured clothes are preferred during, Light coloured clothes are preferred during. Column II: Summer, Winter, Day, Night.[2]
16.A car moves with a speed of 40 km/h for 15 minutes and then with a speed of 60 km/h for the next 15 minutes. The total distance covered by the car is: (i) 100 km (ii) 25 km (iii) 15 km (iv) 10 km[2]
17.Which of the following are not correct? (i) The basic unit of time is second. (ii) Every object moves with a constant speed. (iii) Distances between two cities are measured in kilometres. (iv) The time period of a given pendulum is not constant. (v) The speed of a train is expressed in m/h.[2]
18.State two differences between a real image and a virtual image.[2]
19.Which part of the digestive canal is involved in: (i) absorption of food __________. (ii) chewing of food __________. (iii) killing of bacteria __________. (iv) complete digestion of food __________. (v) formation of faeces __________.[2]
20.Explain why there is a need of variety of animals and plants in a forest.[2]
21.Untreated human excreta is a health hazard. Explain.[2]
22.Which type of lens forms always a virtual image?[2]
🔑 Show Answer Key — Set 1
- 1. (iv) leaves
- 2. (d) between 30 °C and 50 °C
- 3. (d) does not become cold.
- 4. (iv) Kerosene
- 5. (iii) 5 A
- 6. (a) (iii) spiracles (b) (ii) lactic acid (c) (ii) 15-18 (d) (ii) move downwards
- 7. (b) not flow from iron ball to water or from water to iron ball.
- 8. (iii) Forests have no influence on climate.
- 9. (a) (iv) flower (b) (i) fertilisation (c) (iv) fruit (d) (ii) bread mould (e) (ii) leaves
- 10. (ii) concave mirror
- 11. Put a few drops of iodine solution on a leaf. If starch is present, the part of the leaf containing starch turns blue-black.
- 12. A virtual image is an image that cannot be obtained on a screen. A plane mirror forms a virtual image of an object placed in front of it.
- 13. Stomata - Transpiration; Xylem - Transport of water; Root hairs - Absorption of water; Phloem - Transport of food.
- 14. (a) temperature (b) clinical (c) Celsius (d) radiation (e) conduction (f) dark
- 15. Land breeze blows during - Night; Sea breeze blows during - Day; Dark coloured clothes are preferred during - Winter; Light coloured clothes are preferred during - Summer.
- 16. (ii) 25 km
- 17. Statements (ii), (iv) and (v) are not correct.
- 18. A real image can be obtained on a screen, while a virtual image cannot be obtained on a screen. A real image is usually formed when light rays actually meet, while a virtual image appears to be formed where rays seem to come from.
- 19. (i) small intestine (ii) mouth or buccal cavity (iii) stomach (iv) small intestine (v) large intestine
- 20. A variety of plants and animals makes a forest stable. Different organisms depend on one another for food, pollination, seed dispersal, shelter and nutrient recycling. If one kind is lost, many others may be affected.
- 21. Untreated human excreta contains disease-causing microorganisms and can contaminate soil and water. It may spread diseases such as cholera, typhoid, dysentery and hepatitis, so it must be treated safely.
- 22. A concave lens always forms a virtual image.
Brain Grain · braingrain.in
Science — Practice Paper · Set 2
Class: 7CBSE / NCERTMax Marks: 34
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.Which of the following relations is correct? (i) Speed = Distance × Time (ii) Speed = Distance/Time (iii) Speed = Time/Distance (iv) Speed = 1/Distance × Timea. speed = distance × timeb. speed = distance / timec. speed = time / distanced. speed = 1 / distance × time[1]
2.Choose the correct option from the following: Which part of the plant takes in carbon dioxide from the air for photosynthesis? (i) Root hair (ii) Stomata (iii) Leaf veins (iv) Sepalsa. Root hairb. Stomatac. Leaf veinsd. Sepals[1]
3.Choose the correct option: (a) In plants, water is transported through (i) xylem (ii) phloem (iii) stomata (iv) root hair (b) Water absorption through roots can be increased by keeping the plants (i) in the shade (ii) in dim light (iii) under the fan (iv) covered with a polythene baga. xylem / phloem / stomata / root hairb. shade / dim light / under the fan / covered with polythene bag[1]
4.Tick the correct answer: (a) Cuscuta is an example of: (i) autotroph (ii) parasite (iii) saprotroph (iv) host (b) The plant which traps and feeds on insects is: (i) Cuscuta (ii) china rose (iii) pitcher plant (iv) rosea. autotroph / parasite / saprotroph / hostb. Cuscuta / china rose / pitcher plant / rose[1]
5.Stainless steel pans are usually provided with copper bottoms. The reason for this could be that (a) copper bottom makes the pan more durable. (b) such pans appear colourful. (c) copper is a better conductor of heat than the stainless steel. (d) copper is easier to clean than the stainless steel.a. copper bottom makes the pan more durableb. such pans appear colourfulc. copper is a better conductor of heat than the stainless steeld. copper is easier to clean than the stainless steel[1]
6.The basic unit of speed is: (i) km/min (ii) m/min (iii) km/h (iv) m/sa. km/minb. m/minc. km/hd. m/s[1]
7.Choose the correct option from the following: Plants take carbon dioxide from the atmosphere mainly through their: (i) roots (ii) stem (iii) flowers (iv) leavesa. rootb. stemc. leafd. flower[1]
8.One litre of water at 30 °C is mixed with one litre of water at 50 °C. The temperature of the mixture will be (a) 80 °C (b) more than 50 °C but less than 80 °C (c) 20 °C (d) between 30 °C and 50 °Ca. 80 °Cb. more than 50 °C but less than 80 °Cc. 20 °Cd. between 30 °C and 50 °C[1]
9.A wooden spoon is dipped in a cup of ice cream. Its other end (a) becomes cold by the process of conduction. (b) becomes cold by the process of convection. (c) becomes cold by the process of radiation. (d) does not become cold.a. becomes cold by the process of conductionb. becomes cold by the process of convectionc. becomes cold by the process of radiationd. does not become cold[1]
10.Which of the following is not a forest product? (i) Gum (ii) Plywood (iii) Sealing wax (iv) Kerosenea. gumb. plywoodc. sealing waxd. kerosene[1]
Part II — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
11.Name any two effects of electric current.[2]
12.Mark 'T' if the statement is true and 'F' if it is false: (a) To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell. (T/F) (b) When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks. (T/F) (c) An electromagnet does not attract a piece of iron. (T/F) (d) An electric bell has an electromagnet. (T/F)[2]
13.Why do organisms need to take food?[2]
14.State the characteristics of the image formed by a plane mirror.[2]
15.Mark 'T' if the statement is true and 'F' if it is false: (a) We can obtain an enlarged and erect image by a convex mirror. (T/F) (b) A concave lens always form a virtual image. (T/F) (c) We can obtain a real, enlarged and inverted image by a concave mirror. (T/F) (d) A real image cannot be obtained on a screen. (T/F) (e) A concave mirror always form a real image. (T/F)[2]
16.What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.[2]
17.Mark 'T' if the statement is true and 'F' if it is false: (a) Digestion of starch starts in the stomach. (T/F) (b) The tongue helps in mixing food with saliva. (T/F) (c) The gall bladder temporarily stores bile. (T/F) (d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)[2]
18.How does the process of fertilisation take place in flowers?[2]
19.Match the items of Column I with suitable items in Column II: Column I: Salivary gland, Stomach, Liver, Rectum, Small intestine. Column II: Bile juice secretion, Storage of undigested food, Saliva secretion, Acid release, Digestion is completed.[2]
20.Does transpiration serve any useful function in the plants? Explain.[2]
21.Describe the steps involved in getting clarified water from wastewater.[2]
22.Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator.[2]
🔑 Show Answer Key — Set 2
- 1. (ii) Speed = Distance/Time
- 2. (ii) Stomata
- 3. (a) (i) xylem (b) (iii) under the fan
- 4. (a) (ii) parasite (b) (iii) pitcher plant
- 5. (c) copper is a better conductor of heat than the stainless steel.
- 6. (iv) m/s
- 7. (iv) leaves
- 8. (d) between 30 °C and 50 °C
- 9. (d) does not become cold.
- 10. (iv) Kerosene
- 11. Two effects of electric current are the heating effect and the magnetic effect.
- 12. (a) F (b) T (c) F (d) T
- 13. Organisms need food to obtain energy for life processes, to grow, to repair damaged body parts and to maintain health. Food also supplies the materials needed for building the body.
- 14. The image formed by a plane mirror is virtual, erect, of the same size as the object, laterally inverted and appears as far behind the mirror as the object is in front of it.
- 15. (a) F (b) T (c) T (d) F (e) F
- 16. Sewage is wastewater released by homes, industries, hospitals, offices and other users. It contains dissolved and suspended impurities, organic waste, disease-causing microorganisms and chemicals. Discharging untreated sewage into rivers or seas pollutes water, harms aquatic life and spreads diseases.
- 17. (a) F (b) T (c) T (d) T
- 18. After pollination, a pollen grain on the stigma forms a pollen tube that grows through the style to the ovule. The male gamete travels through the tube and fuses with the female gamete in the ovule. This fusion forms a zygote, which develops into an embryo.
- 19. Salivary gland - Saliva secretion; Stomach - Acid release; Liver - Bile juice secretion; Rectum - Storage of undigested food; Small intestine - Digestion is completed.
- 20. Yes. Transpiration creates a suction pull that helps draw water and minerals upward from roots to leaves. It also helps cool the plant.
- 21. Wastewater first passes through bar screens that remove large objects. It then goes to a grit and sand removal tank where sand and grit settle. In a large settling tank, solids settle as sludge and oils or grease are skimmed off. Air is then passed through the clarified water to help aerobic bacteria grow and consume organic waste. The water is finally disinfected before it is released or reused.
- 22. Put a little turmeric indicator in each liquid. Sodium hydroxide is basic, so it turns turmeric reddish-brown. Hydrochloric acid and sugar solution do not give this colour. Now add the reddish-brown basic liquid drop by drop to the two remaining samples; the one that changes the turmeric colour back because of neutralisation is hydrochloric acid, and the other is sugar solution.
Brain Grain · braingrain.in
Science — Practice Paper · Set 3
Class: 7CBSE / NCERTMax Marks: 34
Name: ____________________Reg No: ____________
Part I — Multiple Choice Questions 10 × 1 = 10
Choose the correct answer. (Answer all questions.)
1.An electric iron of 1 kW is operated at 220 V. Which of the following fuses should be used in the circuit? (i) 1 A (ii) 3 A (iii) 5 A (iv) 13 Aa. 1 Ab. 3 Ac. 5 Ad. all of these[1]
2.Tick the correct answer: (a) In cockroaches, air enters the body through (i) lungs (ii) gills (iii) spiracles (iv) skin (b) During heavy exercise, we get cramps in the legs due to the accumulation of (i) carbon dioxide (ii) lactic acid (iii) alcohol (iv) water (c) Normal range of breathing rate per minute in an average adult person at rest is (i) 9-12 (ii) 15-18 (iii) 21-24 (iv) 30-33 (d) During exhalation, the ribs (i) move outwards (ii) move downwards (iii) move upwards (iv) do not move at alla. lungs / gills / spiracles / skinb. CO2 / lactic acid / alcohol / waterc. 9-12 / 15-18 / 21-24 / 30-33d. outwards / downwards / upwards / no movement[1]
3.An iron ball at 40 °C is dropped in a mug containing water at 40 °C. The heat will (a) flow from iron ball to water. (b) not flow from iron ball to water or from water to iron ball. (c) flow from water to iron ball. (d) increase the temperature of both.a. flow from iron ball to waterb. not flow from iron ball to water or from water to iron ballc. flow from water to iron balld. increase the temperature of both[1]
4.Which of the following statements is not correct? (i) Forests protect the soil. (ii) In forests, plants and animals depend on one another. (iii) Forests have no influence on climate. (iv) Soil helps forests to grow and regenerate.a. Forests protect the soil from erosion.b. Plants and animals in a forest are not dependent on one another.c. Forests influence climate, water cycle and air quality.d. Soil helps forests to grow and regenerate.[1]
5.Tick the correct answer: (a) The reproductive part of a plant is the (i) leaf (ii) stem (iii) root (iv) flower (b) The process of fusion of the male and the female gametes is called (i) fertilisation (ii) pollination (iii) reproduction (iv) seed formation (c) Mature ovary forms the (i) seed (ii) stamen (iii) pistil (iv) fruit (d) A spore producing organism is (i) rose (ii) bread mould (iii) potato (iv) ginger (e) Bryophyllum can reproduce by its (i) stem (ii) leaves (iii) roots (iv) flowera. leaf / stem / root / flowerb. fertilisation / pollination / reproduction / seed formationc. seed / stamen / pistil / fruitd. rose / bread mould / potato / gingere. stem / leaves / roots / flower[1]
6.A virtual image larger than the object can be produced by a (i) concave lens (ii) concave mirror (iii) convex mirror (iv) plane mirrora. concave lensb. concave mirrorc. convex mirrord. plane mirror[1]
7.Which of the following relations is correct? (i) Speed = Distance × Time (ii) Speed = Distance/Time (iii) Speed = Time/Distance (iv) Speed = 1/Distance × Timea. speed = distance × timeb. speed = distance / timec. speed = time / distanced. speed = 1 / distance × time[1]
8.Choose the correct option from the following: Which part of the plant takes in carbon dioxide from the air for photosynthesis? (i) Root hair (ii) Stomata (iii) Leaf veins (iv) Sepalsa. Root hairb. Stomatac. Leaf veinsd. Sepals[1]
9.Choose the correct option: (a) In plants, water is transported through (i) xylem (ii) phloem (iii) stomata (iv) root hair (b) Water absorption through roots can be increased by keeping the plants (i) in the shade (ii) in dim light (iii) under the fan (iv) covered with a polythene baga. xylem / phloem / stomata / root hairb. shade / dim light / under the fan / covered with polythene bag[1]
10.Tick the correct answer: (a) Cuscuta is an example of: (i) autotroph (ii) parasite (iii) saprotroph (iv) host (b) The plant which traps and feeds on insects is: (i) Cuscuta (ii) china rose (iii) pitcher plant (iv) rosea. autotroph / parasite / saprotroph / hostb. Cuscuta / china rose / pitcher plant / rose[1]
Part II — Short Answer Questions 12 × 2 = 24
Answer briefly. (Answer all questions.)
11.Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.[2]
12.Fill in the blanks: (a) Cleaning of water is a process of removing __________. (b) Wastewater released by houses is called __________. (c) Dried __________ is used as manure. (d) Drains get blocked by __________ and __________.[2]
13.Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.[2]
14.In places of hot climate it is advised that the outer walls of houses be painted white. Explain.[2]
15.Why is it necessary to excrete waste products?[2]
16.Take three test-tubes. Fill 3/4th of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?[2]
17.Why do we get instant energy from glucose?[2]
18.Why should oils and fats be not released in the drain? Explain.[2]
19.Explain the function of bar screens in a wastewater treatment plant.[2]
20.Can we survive only on raw, leafy vegetables/grass? Discuss.[2]
21.What is sludge? Explain how it is treated.[2]
22.Fill in the blanks: (a) The insects, butterflies, honeybees and birds help flowering plants in __________. (b) A forest is a purifier of __________ and __________. (c) Herbs form the __________ layer in the forest. (d) The decaying leaves and animal droppings in a forest enrich the __________.[2]
🔑 Show Answer Key — Set 3
- 1. (iii) 5 A
- 2. (a) (iii) spiracles (b) (ii) lactic acid (c) (ii) 15-18 (d) (ii) move downwards
- 3. (b) not flow from iron ball to water or from water to iron ball.
- 4. (iii) Forests have no influence on climate.
- 5. (a) (iv) flower (b) (i) fertilisation (c) (iv) fruit (d) (ii) bread mould (e) (ii) leaves
- 6. (ii) concave mirror
- 7. (ii) Speed = Distance/Time
- 8. (ii) Stomata
- 9. (a) (i) xylem (b) (iii) under the fan
- 10. (a) (ii) parasite (b) (iii) pitcher plant
- 11. The solution may be basic or neutral. Blue litmus turns red only in an acidic solution; it remains blue in both basic and neutral solutions. To confirm, red litmus should also be tested: a base turns it blue, while a neutral solution does not change it.
- 12. (a) pollutants (b) sewage (c) sludge (d) oils and fats
- 13. Cellulose can be digested by ruminants but not by humans. Ruminants have bacteria in a special part of the stomach that help digest cellulose, while humans do not have such cellulose-digesting bacteria in their digestive system.
- 14. White surfaces reflect most of the heat radiation falling on them and absorb less heat. Painting outer walls white keeps the house cooler in hot climates.
- 15. Waste products formed in the body can be harmful if they accumulate. Excretion removes these wastes and helps keep the internal environment of the body healthy.
- 16. Test-tube A would have the highest concentration of carbon dioxide. The snail respires and releases carbon dioxide. In test-tube B, the plant uses carbon dioxide during photosynthesis. In test-tube C, the plant uses some of the carbon dioxide released by the snail.
- 17. Glucose is a simple sugar. It does not need much digestion and is absorbed quickly into the blood, so it can be used rapidly by body cells to release energy.
- 18. Oils and fats can harden and block drains and pipes. They also reduce the action of helpful microbes in wastewater treatment, so they should not be released into drains.
- 19. Bar screens remove large objects such as rags, sticks, cans, plastic packets and napkins from wastewater. This protects later treatment equipment and makes the rest of the cleaning process easier.
- 20. No. Raw leafy vegetables provide vitamins, minerals and fibre, but they do not by themselves supply all nutrients in required amounts. Humans also cannot digest cellulose efficiently like ruminants. A balanced diet containing carbohydrates, proteins, fats, vitamins, minerals and water is needed for healthy survival.
- 21. Sludge is the solid waste that settles at the bottom of the settling tank during wastewater treatment. It is removed with a scraper and transferred to a separate tank, where anaerobic bacteria decompose it. Biogas is produced and the dried sludge can be used as manure.
- 22. (a) pollination (b) air and water (c) lowest (d) soil