Science
Q.1 Choose the correct answer:
(i) The aerobic bacteria can be grown in clarified water
a. filtration
b. sewage
c. aeration
d. sedimentation
(ii) The first link in all the food chains are
a. herbivores
b. carnivores
c. green plants
d. none of these
(iii) Which of the following inhibits the seepage of rainwater into ground?
a. a pukka floor
b. playground
c. grass lawn
d. forests land
(iv) The colour of light which is deviated the least by prism in the spectrum of white light is
a. violet
b. green
c. red
d. yellow
(v) The coil of wire contained in heater is known as
a. circuit
b. spring
c. component
d. element
Q.2 Match the column:
Column A Column B
i.Bread mould a. excretion
ii. Rose b. deoxygenated blood
iii. Kidney c. cutting
iv. Platelets d. spores
v. Veins e. blood clotting
Q.3 Fill in the blanks:
i.Doctors use ____________ as a device to amplify the sound of heart.
ii. Taking in of air rich in O2 inside the body is called ___________.
iii. Excessive use of chemical fertilizers make the soil_______________.
OR
Turmeric and litmus are ___________ acid-base indicators.
iv. All green plants possess_______________ in their leaves.
v. Bawri was the traditional way of collecting____________.
Q.4 Give one word/one sentence answer for the following:
i.Name the reaction when an acid is mixed with base.
ii. Define parasites.
iii. Name the process of seepage of water into ground.
iv. In which form the food synthesized by the plants is stored?
OR
Which part of the plant gets carbon-dioxide from the air for photosynthesis?
v. Name a device used to measure speed of vehicle.
Q.5 What is sludge? Explain, how it is treated? 3
Q.6 Explain the factors responsible for the depletion of water table. 3
Q.7 Draw neat and labelled diagram of-
(a) Reproductive parts of a flower
Or
(b) Human Excretory System
Q.8 Write three differences between aerobic and anaerobic respiration. 3
Q.9 (i) Name the respiratory organ in cockroaches through which air enters the boy.
(ii) Why do we often sneeze when we inhale a lot of dust-laden air?
Q.10 Explain why:
(i) An antacid tablet is taken when you suffer from acidity.
(ii) Calamine solution is applied on the skin when an ant bites.
(iii) Factory waste is neutralised before disposing it into the water bodies.
Q.11 The distance between two stations is 450 km. A train takes 5 h to cover this distance. Calculate the speed of the train. 3
Q.12 Mention tree causes of water scarcity in our country. 3
Q.13 The Eucalyptus trees are planted along sewage ponds. Give reason. 3
Q.14 List six products we get from forests. 3
Q.15 (i) What type of mirror is used as a side mirror in a scooter? Why is this type of mirror chosen?
(ii) What is difference between mirror and lens?
Q.16 Draw diagram of an electric bell
On what principle does an electric bell work?
Q.17 (a) What will happen if there are no platelets in the blood?
(b) What are stomata? Give two functions of stomata.
Q.18( a) Which type of mirror can form a real image?
(b) State four characteristics of the image formed by a plane mirror.
(c)Give one use each of a concave and a convex mirror.
Q.19 (i) Why should oils and fats be not released in the drain? Explain.
(ii) What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.
Or
Describe the steps involved in getting clarified water from wastewater.
Q.20 Observe the circuit and attempt the questions that follow it.
I i) Label the parts (i) and (ii)in the circuit.
I ii) Define (i) given in the circuit?
iii) What is the function of (ii) given in circuit?
1 iv) Name any two effects of electric current?
Please click the link below to download CBSE Class 7 Science Question Paper Set Y.