Class 10 Science: CBSE (Official) Sample Question Paper (2024-25) | CBSE Sample Papers For Class 10 PDF Download

 Page 1


MARKING SCHEME 
2024 -25  
Class X Science (086) 
 
Section-A 
1 
A.  2,2,4 
1 
2 
B.  a – (iii), b – (i), c – (iv), d – (ii) 
1 
3 
A.  C2H5OH 
Alternate question for VI 
A. Dilute acid 
1 
4 
C.  A has a pH greater than 7 and B has a pH less than 7 
1 
5 
C. Displacement reaction 
1 
6 
C. X is a non-metal and Y is a metal. 
1 
7 
B. Cooking of food  
1 
8 
D. carbon dioxide in human cells 
1 
9 
B. contraction of left ventricle. 
1 
10 
D. Longer small intestine. 
1 
11 
C. Posture and balance. 
1 
12 
D. sex is not genetically determined in snails. 
1 
13 
B. A ray passing through the centre of curvature and incident obliquely. 
1 
14 
C. Red         Violet 
1 
15 
C. It utilizes 10% of light energy and transfers the rest to the next trophic 
level.  
1 
16 
B. Enrichment of oxygen in the atmosphere. 
1 
17 
A. A is true but R is false 
1 
18 
B. Both A and R are true, and R is not the correct explanation of A 
1 
19 
B. Both A and R are true, and R is not the correct explanation of A 
1 
20 
D. A is false but R is true.  
1 
Page 2


MARKING SCHEME 
2024 -25  
Class X Science (086) 
 
Section-A 
1 
A.  2,2,4 
1 
2 
B.  a – (iii), b – (i), c – (iv), d – (ii) 
1 
3 
A.  C2H5OH 
Alternate question for VI 
A. Dilute acid 
1 
4 
C.  A has a pH greater than 7 and B has a pH less than 7 
1 
5 
C. Displacement reaction 
1 
6 
C. X is a non-metal and Y is a metal. 
1 
7 
B. Cooking of food  
1 
8 
D. carbon dioxide in human cells 
1 
9 
B. contraction of left ventricle. 
1 
10 
D. Longer small intestine. 
1 
11 
C. Posture and balance. 
1 
12 
D. sex is not genetically determined in snails. 
1 
13 
B. A ray passing through the centre of curvature and incident obliquely. 
1 
14 
C. Red         Violet 
1 
15 
C. It utilizes 10% of light energy and transfers the rest to the next trophic 
level.  
1 
16 
B. Enrichment of oxygen in the atmosphere. 
1 
17 
A. A is true but R is false 
1 
18 
B. Both A and R are true, and R is not the correct explanation of A 
1 
19 
B. Both A and R are true, and R is not the correct explanation of A 
1 
20 
D. A is false but R is true.  
1 
Section-B  
21 A. Exothermic/Displacement reaction/Redox reaction.                         (0.5)  
Heat is evolved or a More reactive element displaces a less reactive 
element or aluminium reduces iron (II) oxide to iron                         (0.5) 
B. Double displacement / Precipitation reaction                                    (0.5) 
As there is an exchange of ions between reactants and products /  
(Yellow) precipitate (of Lead iodide) is formed                                 (0.5) 
2 
22 S. 
No. 
Feature Alveoli Nephron 
1 Structure 
and location 
Balloon like structures 
present at the terminal ends 
of bronchioles in lungs 
Tubular structure 
present in kidneys 
2 Function Exchange of gases Filtration of blood 
to form urine 
 
2 
23 
Students to attempt either option A or B. 
A. Steps of synthesis of glucose in plants: 
? Absorption of light energy by chlorophyll 
? Conversion of light energy to chemical energy and splitting of water 
molecules into hydrogen and oxygen 
? Reduction of carbon dioxide into carbohydrates. 
? Desert plants take up carbon dioxide at night and prepare an 
intermediate which is acted upon by the energy absorbed by the 
chlorophyll during the day.                                                  (0.5 x 4) 
OR 
B.  
? Salivary amylase – breaks down starch which is a complex 
molecule to sugar. 
? Pepsin – Helps to digest proteins in stomach. 
? Trypsin – It helps in digesting proteins to amino acids. 
? Lipase – Breaking down of emulsified fats to fatty acids and 
glycerol.                                                                             (0.5 x 4) 
2 
24 A. The lens is a convex lens. 
B. The image is virtual. 
C. Magnification for lens =   
?? ?? =  
h
?? h
??  = 2.  
          
-30????
??  = 2 
Hence u = -15 cm 
- - - - - - - - - - - - 
For visually impaired students 
A. concave lens                                                                                       (1) 
B. correction of myopia and peepholes of doors or any other correct 
alternative.                                                                                          (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
Page 3


MARKING SCHEME 
2024 -25  
Class X Science (086) 
 
Section-A 
1 
A.  2,2,4 
1 
2 
B.  a – (iii), b – (i), c – (iv), d – (ii) 
1 
3 
A.  C2H5OH 
Alternate question for VI 
A. Dilute acid 
1 
4 
C.  A has a pH greater than 7 and B has a pH less than 7 
1 
5 
C. Displacement reaction 
1 
6 
C. X is a non-metal and Y is a metal. 
1 
7 
B. Cooking of food  
1 
8 
D. carbon dioxide in human cells 
1 
9 
B. contraction of left ventricle. 
1 
10 
D. Longer small intestine. 
1 
11 
C. Posture and balance. 
1 
12 
D. sex is not genetically determined in snails. 
1 
13 
B. A ray passing through the centre of curvature and incident obliquely. 
1 
14 
C. Red         Violet 
1 
15 
C. It utilizes 10% of light energy and transfers the rest to the next trophic 
level.  
1 
16 
B. Enrichment of oxygen in the atmosphere. 
1 
17 
A. A is true but R is false 
1 
18 
B. Both A and R are true, and R is not the correct explanation of A 
1 
19 
B. Both A and R are true, and R is not the correct explanation of A 
1 
20 
D. A is false but R is true.  
1 
Section-B  
21 A. Exothermic/Displacement reaction/Redox reaction.                         (0.5)  
Heat is evolved or a More reactive element displaces a less reactive 
element or aluminium reduces iron (II) oxide to iron                         (0.5) 
B. Double displacement / Precipitation reaction                                    (0.5) 
As there is an exchange of ions between reactants and products /  
(Yellow) precipitate (of Lead iodide) is formed                                 (0.5) 
2 
22 S. 
No. 
Feature Alveoli Nephron 
1 Structure 
and location 
Balloon like structures 
present at the terminal ends 
of bronchioles in lungs 
Tubular structure 
present in kidneys 
2 Function Exchange of gases Filtration of blood 
to form urine 
 
2 
23 
Students to attempt either option A or B. 
A. Steps of synthesis of glucose in plants: 
? Absorption of light energy by chlorophyll 
? Conversion of light energy to chemical energy and splitting of water 
molecules into hydrogen and oxygen 
? Reduction of carbon dioxide into carbohydrates. 
? Desert plants take up carbon dioxide at night and prepare an 
intermediate which is acted upon by the energy absorbed by the 
chlorophyll during the day.                                                  (0.5 x 4) 
OR 
B.  
? Salivary amylase – breaks down starch which is a complex 
molecule to sugar. 
? Pepsin – Helps to digest proteins in stomach. 
? Trypsin – It helps in digesting proteins to amino acids. 
? Lipase – Breaking down of emulsified fats to fatty acids and 
glycerol.                                                                             (0.5 x 4) 
2 
24 A. The lens is a convex lens. 
B. The image is virtual. 
C. Magnification for lens =   
?? ?? =  
h
?? h
??  = 2.  
          
-30????
??  = 2 
Hence u = -15 cm 
- - - - - - - - - - - - 
For visually impaired students 
A. concave lens                                                                                       (1) 
B. correction of myopia and peepholes of doors or any other correct 
alternative.                                                                                          (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
25 Student to attempt either A or B.  
A.  P = VI                                                                                                    (1) 
= 230 × 3.5 = 805 W 
I ?
1
?? , so half the resistance means double the current.  
Therefore, current in Y = 7.0 A.                                                             (1) 
OR 
B. For series total resistance is R+2R = 3R                                            (0.5) 
       P1 = 
?? 2
3?? .                                                                                             (0.5) 
For parallel total Resistance is 
2?? 3
.                                                      (0.5) 
P2  =  
?? 2
2?? /3
 =  
3?? 2
2?? .    
?? 1
?? 2
 =   
2
9
.                                                                                                (0.5) 
- - - - - - - - - - - - 
For visually impaired students 
A. The resistance will be lowest/minimum if all the resistors are 
connected in parallel. 
The equivalent resistance in parallel combination is given by           (0.5) 
1
?? ?????? = 
1
?? 1
+
1
?? 2
+
1
?? 3
+
1
?? 4
  
(0.5) 
Substituting the values, we get 
1
?? ??????
 = 
1
3
+
1
6
+
1
9
+
1
12
  
(0.5) 
= 
12 + 6 + 4 + 2
36
= 
24
36
 = 
2
3
 
?? ??????
 = 
3
2
 = 1.5 ?? 
(0.5) 
 
OR 
B. ?? = ?? × ??                                                                                      (0.5) 
?? =
?? ?? = 
1000
220
= 4.54 ??                                                                 (0.5) 
We will be using fuse B with is rated as 5A. This is because it will be 
able to sustain the current (4.54 A) passing through it. Whereas fuse 
A will melt and break the circuit as the current exceeds its rating.   (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26 Pesticides are non-biodegradable/ keep getting accumulated at each trophic 
level, / persist for longer time/ and thus last trophic level has highest 
concentration/ humans will have the highest concentration of pesticides/ 
leads to bio-magnification.                                                         (any 2 points) 
- - - - - - - - - - - - 
For visually impaired students  
2 
Page 4


MARKING SCHEME 
2024 -25  
Class X Science (086) 
 
Section-A 
1 
A.  2,2,4 
1 
2 
B.  a – (iii), b – (i), c – (iv), d – (ii) 
1 
3 
A.  C2H5OH 
Alternate question for VI 
A. Dilute acid 
1 
4 
C.  A has a pH greater than 7 and B has a pH less than 7 
1 
5 
C. Displacement reaction 
1 
6 
C. X is a non-metal and Y is a metal. 
1 
7 
B. Cooking of food  
1 
8 
D. carbon dioxide in human cells 
1 
9 
B. contraction of left ventricle. 
1 
10 
D. Longer small intestine. 
1 
11 
C. Posture and balance. 
1 
12 
D. sex is not genetically determined in snails. 
1 
13 
B. A ray passing through the centre of curvature and incident obliquely. 
1 
14 
C. Red         Violet 
1 
15 
C. It utilizes 10% of light energy and transfers the rest to the next trophic 
level.  
1 
16 
B. Enrichment of oxygen in the atmosphere. 
1 
17 
A. A is true but R is false 
1 
18 
B. Both A and R are true, and R is not the correct explanation of A 
1 
19 
B. Both A and R are true, and R is not the correct explanation of A 
1 
20 
D. A is false but R is true.  
1 
Section-B  
21 A. Exothermic/Displacement reaction/Redox reaction.                         (0.5)  
Heat is evolved or a More reactive element displaces a less reactive 
element or aluminium reduces iron (II) oxide to iron                         (0.5) 
B. Double displacement / Precipitation reaction                                    (0.5) 
As there is an exchange of ions between reactants and products /  
(Yellow) precipitate (of Lead iodide) is formed                                 (0.5) 
2 
22 S. 
No. 
Feature Alveoli Nephron 
1 Structure 
and location 
Balloon like structures 
present at the terminal ends 
of bronchioles in lungs 
Tubular structure 
present in kidneys 
2 Function Exchange of gases Filtration of blood 
to form urine 
 
2 
23 
Students to attempt either option A or B. 
A. Steps of synthesis of glucose in plants: 
? Absorption of light energy by chlorophyll 
? Conversion of light energy to chemical energy and splitting of water 
molecules into hydrogen and oxygen 
? Reduction of carbon dioxide into carbohydrates. 
? Desert plants take up carbon dioxide at night and prepare an 
intermediate which is acted upon by the energy absorbed by the 
chlorophyll during the day.                                                  (0.5 x 4) 
OR 
B.  
? Salivary amylase – breaks down starch which is a complex 
molecule to sugar. 
? Pepsin – Helps to digest proteins in stomach. 
? Trypsin – It helps in digesting proteins to amino acids. 
? Lipase – Breaking down of emulsified fats to fatty acids and 
glycerol.                                                                             (0.5 x 4) 
2 
24 A. The lens is a convex lens. 
B. The image is virtual. 
C. Magnification for lens =   
?? ?? =  
h
?? h
??  = 2.  
          
-30????
??  = 2 
Hence u = -15 cm 
- - - - - - - - - - - - 
For visually impaired students 
A. concave lens                                                                                       (1) 
B. correction of myopia and peepholes of doors or any other correct 
alternative.                                                                                          (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
25 Student to attempt either A or B.  
A.  P = VI                                                                                                    (1) 
= 230 × 3.5 = 805 W 
I ?
1
?? , so half the resistance means double the current.  
Therefore, current in Y = 7.0 A.                                                             (1) 
OR 
B. For series total resistance is R+2R = 3R                                            (0.5) 
       P1 = 
?? 2
3?? .                                                                                             (0.5) 
For parallel total Resistance is 
2?? 3
.                                                      (0.5) 
P2  =  
?? 2
2?? /3
 =  
3?? 2
2?? .    
?? 1
?? 2
 =   
2
9
.                                                                                                (0.5) 
- - - - - - - - - - - - 
For visually impaired students 
A. The resistance will be lowest/minimum if all the resistors are 
connected in parallel. 
The equivalent resistance in parallel combination is given by           (0.5) 
1
?? ?????? = 
1
?? 1
+
1
?? 2
+
1
?? 3
+
1
?? 4
  
(0.5) 
Substituting the values, we get 
1
?? ??????
 = 
1
3
+
1
6
+
1
9
+
1
12
  
(0.5) 
= 
12 + 6 + 4 + 2
36
= 
24
36
 = 
2
3
 
?? ??????
 = 
3
2
 = 1.5 ?? 
(0.5) 
 
OR 
B. ?? = ?? × ??                                                                                      (0.5) 
?? =
?? ?? = 
1000
220
= 4.54 ??                                                                 (0.5) 
We will be using fuse B with is rated as 5A. This is because it will be 
able to sustain the current (4.54 A) passing through it. Whereas fuse 
A will melt and break the circuit as the current exceeds its rating.   (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26 Pesticides are non-biodegradable/ keep getting accumulated at each trophic 
level, / persist for longer time/ and thus last trophic level has highest 
concentration/ humans will have the highest concentration of pesticides/ 
leads to bio-magnification.                                                         (any 2 points) 
- - - - - - - - - - - - 
For visually impaired students  
2 
Cabbage/plant-> rabbit-> snake-> owl (Any other relevant food chain)      (1) 
Pesticides are non-biodegradable and persist for long. So when humans 
consume plants or any animal that consume this plant, the pesticide enters 
the food chain and keeps getting accumulated at each trophic level, thus the 
organism in the last trophic level-human being has the highest concentration 
of pesticide and this is called biological magnification.                               (1) 
Section-C 
27 A. Aqueous solution of magnesium oxide turns red litmus to blue.  
Aluminium oxide is amphoteric and insoluble in water. Thus, it does 
not change the colour of either blue or red litmus.  
       OR 
Magnesium oxide reacts with acid only whereas Aluminium oxide reacts 
with acids and bases, which are amphoteric.                                        (1) 
B.  
 
 (1+1) 
 
- -- - - - - - - - - 
For visually impaired students  
A. Certain metals (like aluminium/ copper) are used for making cooking 
utensils as they are good conductors of heat and have high melting 
points.                                                                                    (0.5 + 0.5) 
B. Hydrogen gas is not evolved when a metal reacts with nitric acid. This 
is because HNO3 is a strong oxidising agent. It oxidises the H2 
produced to water and itself gets reduced to any of the nitrogen oxides 
(N2O, NO, NO2). But magnesium (Mg) and manganese (Mn) react 
with very dilute HNO3 to evolve H2 gas.                                                  (1+1) 
3 
28 Students to attempt either A or B. 
A.  
(i) X = NaHCO3; Z = Na2CO3                                                     (0.5+0.5) 
(ii) Decomposition reaction                                                               (0.5) 
(iii) Solution A                                                                                    (0.5) 
(iv) Increasing order or H+ ions C<B<A                                               (1) 
OR 
B.  
(i) As bee sting is acidic and wasp sting is basic.                                (1) 
(ii) To change the nature of soil to (neutral or basic).                           (1) 
(iii) To protect sculptures from the effects of certain gases present in 
environment and acid rain.                                                               (1) 
3 
 
 
 
 
 
29 ? In plants, the water is absorbed by the plants from the soil through the 
roots. Xylem tissue of the roots, stems and leaves are interconnected 
to form a continuous system of water conducting channels.               (1) 
? During the day, when stomata are open, the transpiration pull becomes 
3 
Page 5


MARKING SCHEME 
2024 -25  
Class X Science (086) 
 
Section-A 
1 
A.  2,2,4 
1 
2 
B.  a – (iii), b – (i), c – (iv), d – (ii) 
1 
3 
A.  C2H5OH 
Alternate question for VI 
A. Dilute acid 
1 
4 
C.  A has a pH greater than 7 and B has a pH less than 7 
1 
5 
C. Displacement reaction 
1 
6 
C. X is a non-metal and Y is a metal. 
1 
7 
B. Cooking of food  
1 
8 
D. carbon dioxide in human cells 
1 
9 
B. contraction of left ventricle. 
1 
10 
D. Longer small intestine. 
1 
11 
C. Posture and balance. 
1 
12 
D. sex is not genetically determined in snails. 
1 
13 
B. A ray passing through the centre of curvature and incident obliquely. 
1 
14 
C. Red         Violet 
1 
15 
C. It utilizes 10% of light energy and transfers the rest to the next trophic 
level.  
1 
16 
B. Enrichment of oxygen in the atmosphere. 
1 
17 
A. A is true but R is false 
1 
18 
B. Both A and R are true, and R is not the correct explanation of A 
1 
19 
B. Both A and R are true, and R is not the correct explanation of A 
1 
20 
D. A is false but R is true.  
1 
Section-B  
21 A. Exothermic/Displacement reaction/Redox reaction.                         (0.5)  
Heat is evolved or a More reactive element displaces a less reactive 
element or aluminium reduces iron (II) oxide to iron                         (0.5) 
B. Double displacement / Precipitation reaction                                    (0.5) 
As there is an exchange of ions between reactants and products /  
(Yellow) precipitate (of Lead iodide) is formed                                 (0.5) 
2 
22 S. 
No. 
Feature Alveoli Nephron 
1 Structure 
and location 
Balloon like structures 
present at the terminal ends 
of bronchioles in lungs 
Tubular structure 
present in kidneys 
2 Function Exchange of gases Filtration of blood 
to form urine 
 
2 
23 
Students to attempt either option A or B. 
A. Steps of synthesis of glucose in plants: 
? Absorption of light energy by chlorophyll 
? Conversion of light energy to chemical energy and splitting of water 
molecules into hydrogen and oxygen 
? Reduction of carbon dioxide into carbohydrates. 
? Desert plants take up carbon dioxide at night and prepare an 
intermediate which is acted upon by the energy absorbed by the 
chlorophyll during the day.                                                  (0.5 x 4) 
OR 
B.  
? Salivary amylase – breaks down starch which is a complex 
molecule to sugar. 
? Pepsin – Helps to digest proteins in stomach. 
? Trypsin – It helps in digesting proteins to amino acids. 
? Lipase – Breaking down of emulsified fats to fatty acids and 
glycerol.                                                                             (0.5 x 4) 
2 
24 A. The lens is a convex lens. 
B. The image is virtual. 
C. Magnification for lens =   
?? ?? =  
h
?? h
??  = 2.  
          
-30????
??  = 2 
Hence u = -15 cm 
- - - - - - - - - - - - 
For visually impaired students 
A. concave lens                                                                                       (1) 
B. correction of myopia and peepholes of doors or any other correct 
alternative.                                                                                          (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
25 Student to attempt either A or B.  
A.  P = VI                                                                                                    (1) 
= 230 × 3.5 = 805 W 
I ?
1
?? , so half the resistance means double the current.  
Therefore, current in Y = 7.0 A.                                                             (1) 
OR 
B. For series total resistance is R+2R = 3R                                            (0.5) 
       P1 = 
?? 2
3?? .                                                                                             (0.5) 
For parallel total Resistance is 
2?? 3
.                                                      (0.5) 
P2  =  
?? 2
2?? /3
 =  
3?? 2
2?? .    
?? 1
?? 2
 =   
2
9
.                                                                                                (0.5) 
- - - - - - - - - - - - 
For visually impaired students 
A. The resistance will be lowest/minimum if all the resistors are 
connected in parallel. 
The equivalent resistance in parallel combination is given by           (0.5) 
1
?? ?????? = 
1
?? 1
+
1
?? 2
+
1
?? 3
+
1
?? 4
  
(0.5) 
Substituting the values, we get 
1
?? ??????
 = 
1
3
+
1
6
+
1
9
+
1
12
  
(0.5) 
= 
12 + 6 + 4 + 2
36
= 
24
36
 = 
2
3
 
?? ??????
 = 
3
2
 = 1.5 ?? 
(0.5) 
 
OR 
B. ?? = ?? × ??                                                                                      (0.5) 
?? =
?? ?? = 
1000
220
= 4.54 ??                                                                 (0.5) 
We will be using fuse B with is rated as 5A. This is because it will be 
able to sustain the current (4.54 A) passing through it. Whereas fuse 
A will melt and break the circuit as the current exceeds its rating.   (1) 
2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26 Pesticides are non-biodegradable/ keep getting accumulated at each trophic 
level, / persist for longer time/ and thus last trophic level has highest 
concentration/ humans will have the highest concentration of pesticides/ 
leads to bio-magnification.                                                         (any 2 points) 
- - - - - - - - - - - - 
For visually impaired students  
2 
Cabbage/plant-> rabbit-> snake-> owl (Any other relevant food chain)      (1) 
Pesticides are non-biodegradable and persist for long. So when humans 
consume plants or any animal that consume this plant, the pesticide enters 
the food chain and keeps getting accumulated at each trophic level, thus the 
organism in the last trophic level-human being has the highest concentration 
of pesticide and this is called biological magnification.                               (1) 
Section-C 
27 A. Aqueous solution of magnesium oxide turns red litmus to blue.  
Aluminium oxide is amphoteric and insoluble in water. Thus, it does 
not change the colour of either blue or red litmus.  
       OR 
Magnesium oxide reacts with acid only whereas Aluminium oxide reacts 
with acids and bases, which are amphoteric.                                        (1) 
B.  
 
 (1+1) 
 
- -- - - - - - - - - 
For visually impaired students  
A. Certain metals (like aluminium/ copper) are used for making cooking 
utensils as they are good conductors of heat and have high melting 
points.                                                                                    (0.5 + 0.5) 
B. Hydrogen gas is not evolved when a metal reacts with nitric acid. This 
is because HNO3 is a strong oxidising agent. It oxidises the H2 
produced to water and itself gets reduced to any of the nitrogen oxides 
(N2O, NO, NO2). But magnesium (Mg) and manganese (Mn) react 
with very dilute HNO3 to evolve H2 gas.                                                  (1+1) 
3 
28 Students to attempt either A or B. 
A.  
(i) X = NaHCO3; Z = Na2CO3                                                     (0.5+0.5) 
(ii) Decomposition reaction                                                               (0.5) 
(iii) Solution A                                                                                    (0.5) 
(iv) Increasing order or H+ ions C<B<A                                               (1) 
OR 
B.  
(i) As bee sting is acidic and wasp sting is basic.                                (1) 
(ii) To change the nature of soil to (neutral or basic).                           (1) 
(iii) To protect sculptures from the effects of certain gases present in 
environment and acid rain.                                                               (1) 
3 
 
 
 
 
 
29 ? In plants, the water is absorbed by the plants from the soil through the 
roots. Xylem tissue of the roots, stems and leaves are interconnected 
to form a continuous system of water conducting channels.               (1) 
? During the day, when stomata are open, the transpiration pull becomes 
3 
the major driving force for the movement of water in the xylem.        (1) 
? Evaporation of water molecules from the stomata creates a suction 
which pulls water from the xylem cells of roots to the stem and then to 
the leaves.                                                                                           (1) 
30 (Any letter which clearly indicated dominant and recessive ears, example, L 
or E or any other) 
A. LL × ll   
        F1= Ll  
        Ll X Ll 
        1LL:2Ll:1ll.                                                                                          (2) 
B. No change in ratio/the ratio of F2 generation will still be 1LL:2Ll:1ll/ ratio 
will be the same.                                                                                
As the cross is still between a pure dominant and recessive allele/ 
genes/ traits/characters /as shown in the cross above.                       (1) 
3 
31 A. Hypermetropia is a defect that causes difficulty in focusing on near 
objects, with clearer vision observed for distant objects.  In Myopia 
distant objects appear blurry while near objects are seen clearly.       (1) 
B.   
(i) The image shows a case of hypermetropia.                                        (0.5) 
(ii) shortening of the eyeball or focal length of the eye lens becomes 
too long.                                                                                     (0.5) 
(iii) No the concave lens would diverge the rays coming to the eyeball 
and will push the image even further, but a convex lens should be 
used which will help to converge the rays and create the image at 
the exact place on the retina.                                                        (1) 
 
- - - - - - - - - - - - 
For visually impaired students  
A. Hypermetropia is a defect that causes difficulty in focusing on near 
objects, with clearer vision observed for distant objects.  In Myopia 
distant objects appear blurry while near objects are seen 
clearly.                                                                                                 (1) 
B. High converging power of eye lens, elongation of eye-ball.                (2) 
3 
32 A.                                                                                                     
     R ? ?? 
     R ? 
?? ?? 
     R = ?? ?? ?? .                                                                                               (1.5) 
B.   
      R = ?? ?? ??                                                                                                
       ?? = R
?? ??   for A =1m
2
 and l =1m, we have 
      ?? = R 
Hence resistivity is the resistance offered by a wire of length 1 m having a 
cross sectional area of 1 m
2
.                                                                  (1.5) 
3 
33 A. Magnetic field strength is inversely proportional to the distance from the 3