Central Institute of Higher Tibetan Studies 2009 CBSE CLASS X - Question Paper

21. Name those parts of the flower which serve the identical function as the subsequent do in the
animals:-
(i) testis (ii) ovary (iii) eggs (iv) sperms
2
22. A graph was plotted to show the energy output of 2 kinds of
respiration. Identify the kinds of respiration denoted by curves A
and B. 2
23. How did the ‘Chipko andolan’ ultimately benefit the local population?
provide any 2 benefits. 2
24.
(i) tag the 2 parts indicated by ques. marks and labelled one and two in the above
diagram.
(ii) Suggest a suitable caption or heading for the above diagram. 2
?
?
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25. Write the number provided to any 6 of the organisms shown in Figure B against their
relevent Trophic levels provided in figure provided beneath. 3
26. The genotype of green stemmed tomato plants is denoted as GG and that of purplestemmed
tomato plants as gg. When these 2 are crossed,
(i) What colour of stem would you expect in their F1 progeny?
(ii) provide the percentage of purple-stemmed plants if F1 plants are self pollinated.
(iii) In what ratio would you obtain the genotypes GG and Gg in the F2 progeny? 3
27. (i) Draw the diagram of heart and tag its 4 chambers
(ii) Construct a table to show the functions of these 4 chambers. 5
OR
Plants absorb water from the soil. How does this water reach the tree tops? discuss in
detail
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MARKING SCHEME
SAMPLE ques. PAPER II
X SCIENCE (THEORY)
Q.No. Value Point Marks
1. 1
2. The atomic number of the metal is 13. The valency of the metal is 3. 1
3. In the 1st case 1
4. Tap water contains dissolved salts and minerals which ionise in water and hence conducts
electricity. Distilled water is a covalent compound so it does not conduct electricity. 1
5. 10 A 1
6. Unsaturated 1
7.
½
1
½
8. ?? Observation (i) is incorrect. 1
?? When the direction of flow of current is changed, the direction of the magnetic field
and hence the direction of force also modifications. 1
9. The reaction of lime with water is an exothermic reaction in which lot of heat is evolved. 1
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CaO + H2O — Ca (OH)2
Ca(OH)2 is called slaked lime or calcium hydroxide 2
10. Na ½
Sodium atom loses 1 electron to attain octet configuration and forms sodium ion.
Chlorine atom has seven electrons in the outermost shell, so it gains the electron lost by the
sodium ion to form the chloride ion. The 2 oppositely charged ions are held together by
strong electrostatic force of attraction to form the ionic bond. 1
½
Ionic compounds have high melting points because a considerable amount of energy is
needed to break the strong inter ionic attraction. 2
11. C3 H6 will show addition reaction C3 H6 is an unsaturated compound with a double bond.
Vegetable oils have long unsaturated carbon chains which on addition of hydrogen in the
presence of catalyst nickel, change into saturated carbon chains. This is called
hydrogenation of oils. 2
1
12. (a) Incorrect. The learner is stating the nature of colours in reverse order.
(b) (i) Colour marked 7
(ii) Colour marked 1
13. (i) On heating, baking soda provide out CO2 which makes cakes and bread rise up, so
they become soft and spongy. 1
(ii) CO2 being heavier than air settles down and forms a layer ranging from the burning
substance and the air, thus cutting off the supply of oxygen. 1
(iii) Its pH value is greater than 7. 1
14. ½
½
1
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radius of curvature of the min = 15cm
15 (a) The major short comings of Mendeleev’s periodic table were.
(i) wrong order of atomic masses.
(ii) Position of hydrogen.
(iii) Position of isotopes. (any two)
?? In the modern periodic table, the elements are organizes in the increasing order of
their atomic numbers instead of atomic masses.
(b) Atomic number
X, Z = 12, 2, 8, 2
Y, Z = 16 2, 8, 6
They belong to the 3rd period.
They will form ionic bond because X is a metal and Y is a non-metal. X loses 2
electrons which will be gained by Y. 5
OR
(a) Atomic mass was the basis of classification of elements in Mendeleev’s periodic
table.
Period means - a periodic reoccurrence of physical and chemical properties.
(b) X3 (PO4)2
X (NO3)2
X SO4.
X belongs to Group II in the periodic table.
It will form ionic compounds because it will readily lose two electrons.
16. (a) Both the expressions are accurate. In the 1st case, I remains constant whereas the
second expression is actual when V remains constant. 2
(b) (i) Melting point of tungsten is very high 1
(ii) ?? Specific Resistance is low
?? comparatively light in weight 2
OR
(i) Meaning of the terms 1
(ii) Rate of change of magnetic flux 1
(iii) Fleming’s Right Hand Rule 1
(iv) Statement of the Rule 1
(v) Electric Generator 1
part B
17. Polythene carry bags, newsprints 1
18. Phototropism the shoot of the plant bends towards light 1
19. Thyroid gland; neck region 1
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20. Coal or petroleum is needed to heat water to produce steam for running the turbines in
thermal plants. Cost of transportation is decreased if the thermal plants are near coal / oil
fields. 2
21. (i) Stamen / anther / androecium
(ii) ovary
(iii) ovules
(iv) pollen grains / pollen
22. A - Anaerobic
B - Aerobic
23. (i) The locals benefited from the forest produce.
(ii) The wildlife and nature were conserved. (any two)
(iii) The quality of air and soil was preserved. 2
24. (i) Spinal cord
(ii) effector = muscle in the arm.
(iii) Reflex action / Reflex arc. 2
25. Producers - one and 8
Primary consumers - 2, five and 7. (any two)
Secondary consumer - 3, 6
Tertiary consumer - four 3
26. (i) green stemmed
(ii) 25%
(iii) GG - one 3
Gg - two or GG : Gg = 1:2
27. Diagram with accurate labelling 3
Table to show heart and functions.
Chambers of the heart Functions
Right Atrium Receives deoxygenated blood.
Right Ventricle Sends deoxygenated blood.
Left Atrium Sends deoxygenated blood to the lungs.
Left Ventricle Sends oxygenated blood to aorta for transporting to
the body
2
OR
Xylem (vessels) of roots, stems and leaves are interconnected to form a continuous column.
Roots also take up mineral salts actively, water moves in as a outcome creating pressure.
The root pressure pushes the water up. Stomatal transpiration creates suction force pulling
up the water from root xylem / transpiration pull. 5

Earning:   Approval pending.