Class 7 Science Question Answers

Melting of wax is a _______ change.A. PhysicalB. ChemicalC. Both A and BD. None of the above

Fill in the blanks.A. Fossil fuels are ______ ______ and __________ .B. Process of separation of different constituents from petroleum is called_________ .C. Least polluting fuel for vehicles is __________.

Which of the following is the canopy? a. Short treesb. Shrubsc. Tall treesd. None of the above

Blue litmus paper is dipped in a solution. It remains blue what is the nature of the solution? Explain.

Choose the correct answer from the Alternatives givenSystole refers to the contraction of:A) Major arteries B) SA nodeC) Atria and ventricles D) All of these

Which one of the following can be used as a biofertilizer?a. Plasmodiumb. Rhizobiumc. Chenopodiumd. Agrobacterium

The process of obtaining wool is:A) shearing sorting scouring and dyeingB) shearing scouring sorting and dyeingC) scouring sorting shearing and dyeingD) sorting scouring shearing and dyeing

A leaf insect looks like leaves and polar bears living in snowy regions have white fur on its skin. Although these animals are very different from each other what is the one way in which they are similar?A. They use their bodies to attack enemies.B. They use their bodies to confuse enemies.C. They use their bodies to prepare food.D. They migrate to long distances to protect themselves from enemies.

Animal nutrition does not include which of the following?A. Mode of intakeB. Cooking of foodC. Nutrient requirementD. Utilization in the body

Blue-baby syndrome is caused byA. Cadmium pollution B. Mercury poisoningC. Chronic exposure to arsenicD. Excess nitrate in drinking waterE. Excess fluoride in drinking water

Consider the following statements.A. Almost all animals are either herbivores or carnivores.B. Human beings rats crows etc. are omnivorous.C. Holozoic mode of nutrition is seen in Amoeba and Paramecium.D. Lysosome involved in the digestion of engulfed food is seen in the contractile vacuole of Amoeba.Which of the above statements are incorrect?A. A C and DB. A B and DC. A and DD. B and D

Quote certain examples of chemical reactions from daily life.

The image formed by a plane mirror is always laterally inverted. A. TrueB. False

The range of clinical thermometer is between:A. $$\begin{gathered} {35}^{0}C \\ textand5{ \\ text2}^{0}C \end{gathered}$$.B. $$\begin{gathered} {25}^{0}C \\ textand3{ \\ text2}^{0}C \end{gathered}$$.C. $$\begin{gathered} {65}^{0}C \\ textand7{ \\ text2}^{0}C \end{gathered}$$.D. $$\begin{gathered} {35}^{0}C \\ textand4{ \\ text2}^{0}C \end{gathered}$$.

Heat is a form of ______ and temperature is a _______ of the amount of heat energy in a body.A) energy measureB) mass measureC) energy instrumentD) mass experiment

Which of the following instruments were used in chandrayaan?A) TMCB) LLRIC) HEXD) All of the above

State true or falseThe range of clinical thermometer is \\[{35^ \\circ }\\] to \\[{43^ \\circ }\\]$$\begin{gathered} left( \\ textA \\ right) \end{gathered}$$ True$$\begin{gathered} left( \\ textB \\ right) \end{gathered}$$ False

Boojho dipped a bar magnet in a heap of iron filings and pulled it out. He found that iron filings were stuck to the magnet in the figure. What are the ends of the magnet that have more iron filings sticking to it called?\n \n \n \n \n

What are the disadvantages of Cyclones?

When a candle burns both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.

Assertion : -Assimilatory roots can photosynthesize Reason :- Assimilatory roots possess chlorophyllA) If both the assertion and the reason are true and the reason is a correct explanation of the assertion .B) If both the assertion and the reason are true but the reason is not a correct explanation of the assertion.C) If the assertion is true but the reason is false.D) If both the assertion and reason are false .

Does pure water conduct electricity?A. YesB. NoC. SometimesD. none of the above

The base of the tongue is sensitive to taste(a) Salty(b) Sweet(c) Bitter(d) Sour

The domestic sewage in large cities(a) Has a high BOD as it contains both aerobic and bacteria(b) Is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs).(c) When treated in STPs does not really require the creation step as the sewage contains adequate oxygen.(d) Has very high amounts of suspended solids and dissolved salts

Coniferous forests in India are found inA. Madhya PradeshB. Himalayan regionsC. Satpura HillsD. Rajasthan

In India per capita forest cover isA. 1.06 haB. 0.06 haC. 0.6 haD. 1.6 ha

Make a table of different types of objects that are made from the same material.

Animal nutrition does not include which of the following?A. Mode of intakeB. Cooking of foodC. Nutrient requirementD. Utilization in the body

Food contaminated with food poisoning bacteria wouldA. SmellB. Change colourC. Look normalD. Be slimy and bitter

Humans and animals are dependent on plants:A. DirectlyB. IndirectlyC. Both A and BD. None of the above

The three top most major crops of the world in terms of major staple food are? A ) Maize Rice Wheat B ) Rice Wheat Maize C) Wheat Maize Rice D) Rice Maize Wheat

What is terrace farming?

What is Symbiotic nutrition(commensalism)?

Fallen leaves from trees are useful because theyA) Solve the problem of fuelwood in village householdsB) Enrich water qualityC) Enrich soil fertilityD) Beautify landscape

A measuring jar is graduated in ml from bottom to top.A. TrueB. False

Explain the term conduction convection and radiation with examples.

What is the difference between Astrophysics and Cosmology?

Most abundant metal in the earth’s crust is ______________.

Unwanted plants growing along with crop plant are called as a. Herbs b. Weeds c. Cropsd. Grass

The contraction of heart is known as:- A. Systole B. Diastole C. SA node D. None of the above.

When zinc carbonate is heated and cooled the change(s) that are observed are:(a)- Physical change(b)- Nuclear change(c)- First chemical and then physical change(d)- First physical and then chemical change

Making a fruit salad with raw fruits. Classify the given statement as chemical or physical change.

Why did Appa first choose the most ripped mangoes to be used for making the mamidi tandra?

Is the human body made of cells or atoms or molecules?

Can we only survive on raw leafy vegetables\/grass? Discuss.

What will be the S.I. unit of heat ?A. Joule (J)B. Joule-sec (J – s)C. Calorie (C)D. Watt (W)

Why do human beings have difficulty breathing at high elevations?A) O2 makes up lower percentage thereB) The temperature is higher thereC) The barometric pressure is higher thereD) Pressure of O2 is lower there.

State the basic differences between a gas and a vapor.

Which of the following does not yield wool?A. YakB. CamelC. GoatD. Woolly dog

How will you separate sand and water from their mixture?

The botanical name of chana is A) Cicer Arietinum B) Phaseolus AureusC) Lablab PurpureusD) Dolichos

State for what purpose bleaching powder is used in water treatment plants.

A biosphere is composed of:(A) Living organisms(B) Living organisms + lithosphere(C) Living organisms + lithosphere + atmosphere(D) Living organisms + lithosphere + atmosphere + hydrosphere

Where does the water present in the egg go after boiling?

_____________ is a method by which yarn is manipulated to create a textile or fabric.A. KnittingB. SpinningC. WeavingD. Ginning

Read the passage and answer the following question.SANDSILTCORALDaylight151013Night5303A student wanted to know where a particular type of fish was most likely to be found during a 24 hour period. He observed a total of 76 fish over several days. The student wanted to present the data to his fishing club. Which of the following statements explains correctly the given data?A. A line graph with the time of day on the independent axisB. A line graph with the type of substrate on the dependent axisC. A bar graph with one bar for sand one for silt and one for coral each subdivided by daylight versus nightD. A bar graph with one bar for daylight and one for a night each subdivided by substrate type

---------- is the purest form of natural water.

Groups of animals which give wool are:A.Sheep goat camel and yakB.Sheep camel lion and rabbitC.Rabbit silkworm buffalo cowD.Goat cow sheep and camel

How much pollution goes into the air each day?

A unicellular organism has?A) Just one cellB) many cellsC) few cellsD) no cells

What is the solar system? Write the names of planets of the solar system in sequence.

What is the base of naming the Indian months? Write the name of Indian months and describe their position in the sky at that time.

Sum of potential energy and kinetic energy is called_________.

Vermi-processing toilet is beneficial becausea) It reduces the diseasesb) It increases soil fertilityc) Both a and bd) It reduces electricity

“Ozone hole” meansa) A large-sized hole in the ozone layerb) Thinning of the ozone layerc) Small holes scattered in the ozone layerd) Thickening of ozone in the ozone layer.

When phenolphthalein is added to$NaOH$ the colour of the solution will become _________(a)- Colorless(b)- Red(c)- Pink(d)- Yellow

The water bearing layer of the earth is ______.

Edaphology isa. Study of snakesb. Study of amphibiansc. Study of elephantsd. Study of soils

An animal that feeds upon organic matter dead insects and its own cutoff cuticle maybeA. HerbivorousB. ScavengerC. OmnivorousD. Carnivorous

Photosynthesis occurs in (a)Leaves(b)Leaf cells(c)Plants(d)Chloroplasts

How does particle movement differ in different states of matter?

The material used for making the armature of electric bell isA. aluminumB. soft ironC. steelD. bronze

(a)What is wind? What type of energy is possessed by the wind?(b) Explain how wind energy can be used to generate electricity. Illustrate your answer with the help of a labeled diagram.(c) State two advantages of using wind energy for generating electricity.(d) mention two limitations of wind energy for generating electricity.

Loamy soil is a mixture of ___________ known as silt.a) Sand b) Clay c) Another type of soil particle d) all of the above

Select the incorrect statements:A. Arteries have thick elastic walls and veins have valves.B. Capillaries are the smallest blood vessels supplying the tissues.C. AV nodes are known as the pace setter of the heart.D. Arteries carry blood towards the heart and veins carry blood away from the heart to different organs.A. A and BB. A and CC. C and DD. D only

Where does the oxygen come from when it is liberated during photosynthesis?

During summer if you go near the lake you feel relief from heat. Why?

During day time which of the following is more prevalent?A. Sea breezeB. Land breezeC. Both A and BD. None of these

A cloud seeding is a form ofA) Weather modificationB) Removal of mineral from seawaterC) Rainwater harvestingD) None of the above

The ruminant stomach has four; but camel lacks one part i.e. _______a. Abomasumb. Omasumc. Rumend. Reticulum

Tomato is a juicy fruit that tastes sweet and sour.A. True B. False

Ragi is the richest source ofA. IronB. CalciumC. IodineD. Vit B complex

Choose the correct statement about I II and III.\n \n \n \n \n (A) I and II have definite volume but III does not have this property.(B) I II and III are interconvertible by changing the conditions of temperature and pressure.(C) In the particles of I freedom of movement is large.(D) Both A and B.

(a) What is the difference between a thermal power plant and a hydropower plant?(b) Which of the two causes serious air pollution and how?

How does a lion's life depend on producers?

Seema is planning a trip to Kashmir this summer. Which of the following clothes should she definitely pack?A. Denim JacketB. Leather pantsC. Woolen Sweater D. Cotton shirt

How to calculate ammeter and voltmeter readings?

During heavy exercise we get cramps in the legs due to the accumulation ofA. Carbon dioxideB. Lactic acidC. AlcoholD. Water

Which of the following can replenish nutrients in the soil?A. FertilizerB. ManureC. CompostD. All of the above

Vermi-processing toilet is:A. Alternative sources of energyB. Alternative arrangement of sewage disposalC. Alternative arrangement of sewage treatmentD. None of the above

The non-metallic component in stainless steel is:(A) Sulphur(B) phosphorus(C) carbon(D) iodine

Forest floor is known as the floor for the animal habitat. Which of the following animals are present on the forest floor?A. ParrotB. SnakesC. PigeonD. None of the above

The circulation of water between ocean and land is known as:A) Oxygen CycleB) Water CycleC) Nitrogen CycleD) None of these

The man who has won Nobel Prize twice in physics is A. EinsteinB. BardeenC. HeisenbergD. Faraday

An optician while testing the eyes of a patient keeps a chart of letters 3m behind the patient and asks her to see the letters on the image of the chart formed in a mirror kept at distance 2m in front of her. How far is the chart seen by the patient?a. 3mb. 2mc. 6md. 7m

State similarities and differences between the laboratory thermometer and the clinical thermometer.

Explain the factors responsible for the depletion of water table:

The material similar to silk in appearance is: A. NylonB. RayonC. PolyesterD. Terylene

Jhoolan put a few drops of lemon juice in Jhumpa’s mouth. Do you think we can make out the taste with just a few drops?

Which of the following instruments is used to measure rainfall?(a)Barometer (b)Thermometer (c)Rain Gauge(d)All of the above