Science Past Year Paper SA-2 Solution(Set -3 Outside Delhi) - 2015, Class 10, CBSE Class 10 Notes | EduRev

Past Year Papers For Class 10

Created by: Manju Sen

Class 10 : Science Past Year Paper SA-2 Solution(Set -3 Outside Delhi) - 2015, Class 10, CBSE Class 10 Notes | EduRev

 Page 1


Delhi – 31/1/3 Page 1 
 
Strictly Confidential- (For Internal and Restricted Use Only) Secondary School Examination 
SUMMATIVE ASSESSMENT - II 
March 2015 
 
Marking Scheme – Science (Delhi) 31/1/3 
 
 
1. The Marking Scheme provides general guidelines to reduce subjectivity in the marking. It carries 
only suggested value points for the answer. These are only guidelines and do not constitute the 
complete answer. Any other individual response with suitable justification should also be 
accepted even if there is no reference to the text. 
 
2. Evaluation is to be done as per instructions provided in the Marking Scheme. It should not be 
done according to one's own interpretation or any other consideration. Marking Scheme should 
be strictly adhered to and religiously followed. 
 
3. If a question has parts, please award marks in the right hand side for each part. Marks awarded 
for different parts of the question should then be totalled up and written in the left hand margin. 
 
4. If a question does not have any parts, marks be awarded in the left hand side margin. 
 
5. If a candidate has attempted an extra question, marks obtained in the question attempted first 
should be retained and the other answer should be scored out. 
 
6. Wherever only two/three of a 'given' number of examples/factors/points are expected only the 
first two/three or expected number should be read. The rest are irrelevant and should not be 
examined. 
 
7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual 
total marks obtained by the candidate may be of no concern of the evaluators. 
 
8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the 
answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and 
awarded ‘0’ marks. 
  
9. ½ mark may be deducted if a candidate either does not write units or writes wrong units in the 
final answer of a numerical problem. 
 
10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the 
answer deserves it. 
 
11. As per orders of the Hon’ble Supreme Court the candidates would now be permitted to obtain 
photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head 
Examiners are once again reminded that they must ensure that evaluation is carried out strictly 
as per value points given in the marking scheme. 
 
 
 
 
Page 2


Delhi – 31/1/3 Page 1 
 
Strictly Confidential- (For Internal and Restricted Use Only) Secondary School Examination 
SUMMATIVE ASSESSMENT - II 
March 2015 
 
Marking Scheme – Science (Delhi) 31/1/3 
 
 
1. The Marking Scheme provides general guidelines to reduce subjectivity in the marking. It carries 
only suggested value points for the answer. These are only guidelines and do not constitute the 
complete answer. Any other individual response with suitable justification should also be 
accepted even if there is no reference to the text. 
 
2. Evaluation is to be done as per instructions provided in the Marking Scheme. It should not be 
done according to one's own interpretation or any other consideration. Marking Scheme should 
be strictly adhered to and religiously followed. 
 
3. If a question has parts, please award marks in the right hand side for each part. Marks awarded 
for different parts of the question should then be totalled up and written in the left hand margin. 
 
4. If a question does not have any parts, marks be awarded in the left hand side margin. 
 
5. If a candidate has attempted an extra question, marks obtained in the question attempted first 
should be retained and the other answer should be scored out. 
 
6. Wherever only two/three of a 'given' number of examples/factors/points are expected only the 
first two/three or expected number should be read. The rest are irrelevant and should not be 
examined. 
 
7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual 
total marks obtained by the candidate may be of no concern of the evaluators. 
 
8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the 
answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and 
awarded ‘0’ marks. 
  
9. ½ mark may be deducted if a candidate either does not write units or writes wrong units in the 
final answer of a numerical problem. 
 
10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the 
answer deserves it. 
 
11. As per orders of the Hon’ble Supreme Court the candidates would now be permitted to obtain 
photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head 
Examiners are once again reminded that they must ensure that evaluation is carried out strictly 
as per value points given in the marking scheme. 
 
 
 
 
Delhi – 31/1/3 Page 2 
 
MARKING SCHEME 
CLASS X – DELHI 
Code No. 31/1/3 
 
 
 Expected Answer/ Value point Marks Total 
 SECTION – A   
    
Q1. ? Propyne ½   
 ? C
3
H
4
 ½  1  
    
Q2. Formation of new species from the pre-existing population 1 1 
    
Q3. So that the time and energy required in segregation may be saved and 
waste may be disposed off quickly 
                                                                                    Or any other 
 
 
1 
 
 
1 
    
Q4. i) Virtual 
ii) Erect 
iii) Diminished 
iv) Object distance more than image distance ½ × 4 2 
    
Q5. Two advantages:  
(i) Recharges ground water 
(ii) Mitigates floods and droughts 
(iii) Brings rivers and wells back to life and makes more water available 
                                                                                         (any two) 
 
 
 
1,1 
 
 
 
2 
    
Q6. Four activities: 
i) Reduce excessive use of natural resources like water, fossil fuels, 
etc.. 
ii) Reuse of some resources instead of wasting (throwing) them, like 
empty bottles. 
iii) Recycle the materials like paper to reduce the pressure on 
existing natural resources. 
iv) Changes in lifestyle, personal attitudes and practices. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (or any other) ½ × 4 2 
    
Q7.  Ethene      ,                         H         H ½, ½   
                                             \        /   
                                             C = C   
                                             /        \ 
                                            H          H 
                   Conc. H
2
SO
4
        
 C
2
H
5
OH                                   C
2
H
4   
+  H
2
O 1  
                        443 K   
    
 Conc. H
2
SO
4
 acts as a dehydrating agent. 1 3 
    
Page 3


Delhi – 31/1/3 Page 1 
 
Strictly Confidential- (For Internal and Restricted Use Only) Secondary School Examination 
SUMMATIVE ASSESSMENT - II 
March 2015 
 
Marking Scheme – Science (Delhi) 31/1/3 
 
 
1. The Marking Scheme provides general guidelines to reduce subjectivity in the marking. It carries 
only suggested value points for the answer. These are only guidelines and do not constitute the 
complete answer. Any other individual response with suitable justification should also be 
accepted even if there is no reference to the text. 
 
2. Evaluation is to be done as per instructions provided in the Marking Scheme. It should not be 
done according to one's own interpretation or any other consideration. Marking Scheme should 
be strictly adhered to and religiously followed. 
 
3. If a question has parts, please award marks in the right hand side for each part. Marks awarded 
for different parts of the question should then be totalled up and written in the left hand margin. 
 
4. If a question does not have any parts, marks be awarded in the left hand side margin. 
 
5. If a candidate has attempted an extra question, marks obtained in the question attempted first 
should be retained and the other answer should be scored out. 
 
6. Wherever only two/three of a 'given' number of examples/factors/points are expected only the 
first two/three or expected number should be read. The rest are irrelevant and should not be 
examined. 
 
7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual 
total marks obtained by the candidate may be of no concern of the evaluators. 
 
8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the 
answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and 
awarded ‘0’ marks. 
  
9. ½ mark may be deducted if a candidate either does not write units or writes wrong units in the 
final answer of a numerical problem. 
 
10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the 
answer deserves it. 
 
11. As per orders of the Hon’ble Supreme Court the candidates would now be permitted to obtain 
photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head 
Examiners are once again reminded that they must ensure that evaluation is carried out strictly 
as per value points given in the marking scheme. 
 
 
 
 
Delhi – 31/1/3 Page 2 
 
MARKING SCHEME 
CLASS X – DELHI 
Code No. 31/1/3 
 
 
 Expected Answer/ Value point Marks Total 
 SECTION – A   
    
Q1. ? Propyne ½   
 ? C
3
H
4
 ½  1  
    
Q2. Formation of new species from the pre-existing population 1 1 
    
Q3. So that the time and energy required in segregation may be saved and 
waste may be disposed off quickly 
                                                                                    Or any other 
 
 
1 
 
 
1 
    
Q4. i) Virtual 
ii) Erect 
iii) Diminished 
iv) Object distance more than image distance ½ × 4 2 
    
Q5. Two advantages:  
(i) Recharges ground water 
(ii) Mitigates floods and droughts 
(iii) Brings rivers and wells back to life and makes more water available 
                                                                                         (any two) 
 
 
 
1,1 
 
 
 
2 
    
Q6. Four activities: 
i) Reduce excessive use of natural resources like water, fossil fuels, 
etc.. 
ii) Reuse of some resources instead of wasting (throwing) them, like 
empty bottles. 
iii) Recycle the materials like paper to reduce the pressure on 
existing natural resources. 
iv) Changes in lifestyle, personal attitudes and practices. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (or any other) ½ × 4 2 
    
Q7.  Ethene      ,                         H         H ½, ½   
                                             \        /   
                                             C = C   
                                             /        \ 
                                            H          H 
                   Conc. H
2
SO
4
        
 C
2
H
5
OH                                   C
2
H
4   
+  H
2
O 1  
                        443 K   
    
 Conc. H
2
SO
4
 acts as a dehydrating agent. 1 3 
    
Delhi – 31/1/3 Page 3 
 
Q8. ? Example
:  
 
½  
 ? Addition of hydrogen to the molecule of an unsaturated hydrocarbon 
/compounds is hydrogenation. ½  
 ? Essential condition for hydrogenation is the presence of a catalyst 
like Ni /Pd / Pt. 1  
 ? Change observed in the physical property during hydrogenation is 
the change of the unsaturated compound from the liquid state to the 
corresponding saturated compound in the solid state / its boiling or 
melting point will increase. 1 3 
    
Q9. (i) K / Potassium. 1  
 (ii) Be and Ca. 1  
 ? KX or KCl ½   
 ? Ionic / Electrovalent. ½  3  
    
Q10. No. of periods : 7 ½  
 Valency across a period increases from 1 to 4 , then decreases from 4 to 
zero. 1  
 Metallic character of elements across a period decreases. ½  
    
 Valency down a group remains the same. ½  
 Atomic size of elements down a group increases. ½ 3 
    
Q11 ? Four methods –  
(i)       Mechanical or barrier method  OR  Male or female condoms 
(ii) Use of hormonal preparations  OR  Oral Pills / i-pill / Saheli 
(iii) Use of loop or copper T  OR  IUCD 
(iv) Surgical method  OR  tubectomy / vasectomy 
 
? Effect on health & prosperity:  
(i)       Health of women is maintained 
(ii)       Parents can give more attention to children 
(iii) More resources can be made available. 
                                                                            (any two) 
 
 
 
 
 
½ x 4 
 
 
 
 
½ × 2 
 
 
 
 
 
 
 
 
 
 
3 
    
Q12. a) (i) Hyphae / mycelium 
    (ii) Sporangia 
 
b) Structures protected by thick walls. 
 
Function:  - They germinate into new individuals under favourable 
conditions. 
½ 
½ 
 
1 
 
1 
 
 
 
 
 
3 
    
Page 4


Delhi – 31/1/3 Page 1 
 
Strictly Confidential- (For Internal and Restricted Use Only) Secondary School Examination 
SUMMATIVE ASSESSMENT - II 
March 2015 
 
Marking Scheme – Science (Delhi) 31/1/3 
 
 
1. The Marking Scheme provides general guidelines to reduce subjectivity in the marking. It carries 
only suggested value points for the answer. These are only guidelines and do not constitute the 
complete answer. Any other individual response with suitable justification should also be 
accepted even if there is no reference to the text. 
 
2. Evaluation is to be done as per instructions provided in the Marking Scheme. It should not be 
done according to one's own interpretation or any other consideration. Marking Scheme should 
be strictly adhered to and religiously followed. 
 
3. If a question has parts, please award marks in the right hand side for each part. Marks awarded 
for different parts of the question should then be totalled up and written in the left hand margin. 
 
4. If a question does not have any parts, marks be awarded in the left hand side margin. 
 
5. If a candidate has attempted an extra question, marks obtained in the question attempted first 
should be retained and the other answer should be scored out. 
 
6. Wherever only two/three of a 'given' number of examples/factors/points are expected only the 
first two/three or expected number should be read. The rest are irrelevant and should not be 
examined. 
 
7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual 
total marks obtained by the candidate may be of no concern of the evaluators. 
 
8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the 
answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and 
awarded ‘0’ marks. 
  
9. ½ mark may be deducted if a candidate either does not write units or writes wrong units in the 
final answer of a numerical problem. 
 
10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the 
answer deserves it. 
 
11. As per orders of the Hon’ble Supreme Court the candidates would now be permitted to obtain 
photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head 
Examiners are once again reminded that they must ensure that evaluation is carried out strictly 
as per value points given in the marking scheme. 
 
 
 
 
Delhi – 31/1/3 Page 2 
 
MARKING SCHEME 
CLASS X – DELHI 
Code No. 31/1/3 
 
 
 Expected Answer/ Value point Marks Total 
 SECTION – A   
    
Q1. ? Propyne ½   
 ? C
3
H
4
 ½  1  
    
Q2. Formation of new species from the pre-existing population 1 1 
    
Q3. So that the time and energy required in segregation may be saved and 
waste may be disposed off quickly 
                                                                                    Or any other 
 
 
1 
 
 
1 
    
Q4. i) Virtual 
ii) Erect 
iii) Diminished 
iv) Object distance more than image distance ½ × 4 2 
    
Q5. Two advantages:  
(i) Recharges ground water 
(ii) Mitigates floods and droughts 
(iii) Brings rivers and wells back to life and makes more water available 
                                                                                         (any two) 
 
 
 
1,1 
 
 
 
2 
    
Q6. Four activities: 
i) Reduce excessive use of natural resources like water, fossil fuels, 
etc.. 
ii) Reuse of some resources instead of wasting (throwing) them, like 
empty bottles. 
iii) Recycle the materials like paper to reduce the pressure on 
existing natural resources. 
iv) Changes in lifestyle, personal attitudes and practices. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (or any other) ½ × 4 2 
    
Q7.  Ethene      ,                         H         H ½, ½   
                                             \        /   
                                             C = C   
                                             /        \ 
                                            H          H 
                   Conc. H
2
SO
4
        
 C
2
H
5
OH                                   C
2
H
4   
+  H
2
O 1  
                        443 K   
    
 Conc. H
2
SO
4
 acts as a dehydrating agent. 1 3 
    
Delhi – 31/1/3 Page 3 
 
Q8. ? Example
:  
 
½  
 ? Addition of hydrogen to the molecule of an unsaturated hydrocarbon 
/compounds is hydrogenation. ½  
 ? Essential condition for hydrogenation is the presence of a catalyst 
like Ni /Pd / Pt. 1  
 ? Change observed in the physical property during hydrogenation is 
the change of the unsaturated compound from the liquid state to the 
corresponding saturated compound in the solid state / its boiling or 
melting point will increase. 1 3 
    
Q9. (i) K / Potassium. 1  
 (ii) Be and Ca. 1  
 ? KX or KCl ½   
 ? Ionic / Electrovalent. ½  3  
    
Q10. No. of periods : 7 ½  
 Valency across a period increases from 1 to 4 , then decreases from 4 to 
zero. 1  
 Metallic character of elements across a period decreases. ½  
    
 Valency down a group remains the same. ½  
 Atomic size of elements down a group increases. ½ 3 
    
Q11 ? Four methods –  
(i)       Mechanical or barrier method  OR  Male or female condoms 
(ii) Use of hormonal preparations  OR  Oral Pills / i-pill / Saheli 
(iii) Use of loop or copper T  OR  IUCD 
(iv) Surgical method  OR  tubectomy / vasectomy 
 
? Effect on health & prosperity:  
(i)       Health of women is maintained 
(ii)       Parents can give more attention to children 
(iii) More resources can be made available. 
                                                                            (any two) 
 
 
 
 
 
½ x 4 
 
 
 
 
½ × 2 
 
 
 
 
 
 
 
 
 
 
3 
    
Q12. a) (i) Hyphae / mycelium 
    (ii) Sporangia 
 
b) Structures protected by thick walls. 
 
Function:  - They germinate into new individuals under favourable 
conditions. 
½ 
½ 
 
1 
 
1 
 
 
 
 
 
3 
    
Delhi – 31/1/3 Page 4 
 
    
Q13.  A – Stigma – receives pollen grains. 
 
B – Pollen tube – carries male gamete 
 
C – Female germ cell / egg – formation of zygote 
1 
 
1 
 
1 
 
 
 
 
3 
    
Q14. (i) No, the structure of the eye in each of the organisms is different. 
(ii) ? Fossils of certain dinosaurs / reptiles show imprints of feathers 
along with their bones but they could not fly presumably using 
the feathers for insulation; 
? Later they developed / evolved and adapted feathers for flight, 
thus becoming the ancestors of present day birds. (OR any 
other suitable evidence/example) 
½, ½ 
 
 
1 
 
 
1 
 
 
 
 
 
 
3 
    
Q15. Acquired Traits 
 
(i) Does not bring about change in 
the DNA of the germ cell. 
(ii) Cannot be passed on to the 
progeny. 
(iii) Cannot direct evolution. 
 
Examples: Acquiring knowledge, 
loss of weight or any other 
example 
Inherited Traits 
 
(i) Brings about change in the DNA 
of the germ cell. 
(ii) Can be passed on to the 
progeny. 
(iii) Can direct evolution. 
                                       (any two) 
Examples: Skin colour, colour of 
the eye or any other example. 
 
 
 
 
 
 
 
1,1 
 
 
½ x 2 
 
 
 
 
 
 
 
 
 
 
3 
    
Q16. The candidate may choose any two of the following rays:   
 i) A ray parallel to the principal axis, after reflection, will pass through 
the principal focus of a concave mirror. 
ii) A ray passing through the principal focus of a concave mirror after 
reflection will emerge parallel to the principal axis. 
iii) A ray passing through the centre of curvature of a concave mirror 
after reflection is reflected back along the same path. 
iv) A ray incident obliquely to the principal axis towards the pole of a 
concave mirror is reflected obliquely, making equal angles with the 
principal axis. 
(any two) 1 × 2  
 
 
1 3 
    
Page 5


Delhi – 31/1/3 Page 1 
 
Strictly Confidential- (For Internal and Restricted Use Only) Secondary School Examination 
SUMMATIVE ASSESSMENT - II 
March 2015 
 
Marking Scheme – Science (Delhi) 31/1/3 
 
 
1. The Marking Scheme provides general guidelines to reduce subjectivity in the marking. It carries 
only suggested value points for the answer. These are only guidelines and do not constitute the 
complete answer. Any other individual response with suitable justification should also be 
accepted even if there is no reference to the text. 
 
2. Evaluation is to be done as per instructions provided in the Marking Scheme. It should not be 
done according to one's own interpretation or any other consideration. Marking Scheme should 
be strictly adhered to and religiously followed. 
 
3. If a question has parts, please award marks in the right hand side for each part. Marks awarded 
for different parts of the question should then be totalled up and written in the left hand margin. 
 
4. If a question does not have any parts, marks be awarded in the left hand side margin. 
 
5. If a candidate has attempted an extra question, marks obtained in the question attempted first 
should be retained and the other answer should be scored out. 
 
6. Wherever only two/three of a 'given' number of examples/factors/points are expected only the 
first two/three or expected number should be read. The rest are irrelevant and should not be 
examined. 
 
7. There should be no effort at 'moderation' of the marks by the evaluating teachers. The actual 
total marks obtained by the candidate may be of no concern of the evaluators. 
 
8. All the Head Examiners / Examiners are instructed that while evaluating the answer scripts, if the 
answer is found to be totally incorrect, the (X) should be marked on the incorrect answer and 
awarded ‘0’ marks. 
  
9. ½ mark may be deducted if a candidate either does not write units or writes wrong units in the 
final answer of a numerical problem. 
 
10. A full scale of mark 0 to 100 has to be used. Please do not hesitate to award full marks if the 
answer deserves it. 
 
11. As per orders of the Hon’ble Supreme Court the candidates would now be permitted to obtain 
photocopy of the Answer Book on request on payment of the prescribed fee. All Examiners/Head 
Examiners are once again reminded that they must ensure that evaluation is carried out strictly 
as per value points given in the marking scheme. 
 
 
 
 
Delhi – 31/1/3 Page 2 
 
MARKING SCHEME 
CLASS X – DELHI 
Code No. 31/1/3 
 
 
 Expected Answer/ Value point Marks Total 
 SECTION – A   
    
Q1. ? Propyne ½   
 ? C
3
H
4
 ½  1  
    
Q2. Formation of new species from the pre-existing population 1 1 
    
Q3. So that the time and energy required in segregation may be saved and 
waste may be disposed off quickly 
                                                                                    Or any other 
 
 
1 
 
 
1 
    
Q4. i) Virtual 
ii) Erect 
iii) Diminished 
iv) Object distance more than image distance ½ × 4 2 
    
Q5. Two advantages:  
(i) Recharges ground water 
(ii) Mitigates floods and droughts 
(iii) Brings rivers and wells back to life and makes more water available 
                                                                                         (any two) 
 
 
 
1,1 
 
 
 
2 
    
Q6. Four activities: 
i) Reduce excessive use of natural resources like water, fossil fuels, 
etc.. 
ii) Reuse of some resources instead of wasting (throwing) them, like 
empty bottles. 
iii) Recycle the materials like paper to reduce the pressure on 
existing natural resources. 
iv) Changes in lifestyle, personal attitudes and practices. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 (or any other) ½ × 4 2 
    
Q7.  Ethene      ,                         H         H ½, ½   
                                             \        /   
                                             C = C   
                                             /        \ 
                                            H          H 
                   Conc. H
2
SO
4
        
 C
2
H
5
OH                                   C
2
H
4   
+  H
2
O 1  
                        443 K   
    
 Conc. H
2
SO
4
 acts as a dehydrating agent. 1 3 
    
Delhi – 31/1/3 Page 3 
 
Q8. ? Example
:  
 
½  
 ? Addition of hydrogen to the molecule of an unsaturated hydrocarbon 
/compounds is hydrogenation. ½  
 ? Essential condition for hydrogenation is the presence of a catalyst 
like Ni /Pd / Pt. 1  
 ? Change observed in the physical property during hydrogenation is 
the change of the unsaturated compound from the liquid state to the 
corresponding saturated compound in the solid state / its boiling or 
melting point will increase. 1 3 
    
Q9. (i) K / Potassium. 1  
 (ii) Be and Ca. 1  
 ? KX or KCl ½   
 ? Ionic / Electrovalent. ½  3  
    
Q10. No. of periods : 7 ½  
 Valency across a period increases from 1 to 4 , then decreases from 4 to 
zero. 1  
 Metallic character of elements across a period decreases. ½  
    
 Valency down a group remains the same. ½  
 Atomic size of elements down a group increases. ½ 3 
    
Q11 ? Four methods –  
(i)       Mechanical or barrier method  OR  Male or female condoms 
(ii) Use of hormonal preparations  OR  Oral Pills / i-pill / Saheli 
(iii) Use of loop or copper T  OR  IUCD 
(iv) Surgical method  OR  tubectomy / vasectomy 
 
? Effect on health & prosperity:  
(i)       Health of women is maintained 
(ii)       Parents can give more attention to children 
(iii) More resources can be made available. 
                                                                            (any two) 
 
 
 
 
 
½ x 4 
 
 
 
 
½ × 2 
 
 
 
 
 
 
 
 
 
 
3 
    
Q12. a) (i) Hyphae / mycelium 
    (ii) Sporangia 
 
b) Structures protected by thick walls. 
 
Function:  - They germinate into new individuals under favourable 
conditions. 
½ 
½ 
 
1 
 
1 
 
 
 
 
 
3 
    
Delhi – 31/1/3 Page 4 
 
    
Q13.  A – Stigma – receives pollen grains. 
 
B – Pollen tube – carries male gamete 
 
C – Female germ cell / egg – formation of zygote 
1 
 
1 
 
1 
 
 
 
 
3 
    
Q14. (i) No, the structure of the eye in each of the organisms is different. 
(ii) ? Fossils of certain dinosaurs / reptiles show imprints of feathers 
along with their bones but they could not fly presumably using 
the feathers for insulation; 
? Later they developed / evolved and adapted feathers for flight, 
thus becoming the ancestors of present day birds. (OR any 
other suitable evidence/example) 
½, ½ 
 
 
1 
 
 
1 
 
 
 
 
 
 
3 
    
Q15. Acquired Traits 
 
(i) Does not bring about change in 
the DNA of the germ cell. 
(ii) Cannot be passed on to the 
progeny. 
(iii) Cannot direct evolution. 
 
Examples: Acquiring knowledge, 
loss of weight or any other 
example 
Inherited Traits 
 
(i) Brings about change in the DNA 
of the germ cell. 
(ii) Can be passed on to the 
progeny. 
(iii) Can direct evolution. 
                                       (any two) 
Examples: Skin colour, colour of 
the eye or any other example. 
 
 
 
 
 
 
 
1,1 
 
 
½ x 2 
 
 
 
 
 
 
 
 
 
 
3 
    
Q16. The candidate may choose any two of the following rays:   
 i) A ray parallel to the principal axis, after reflection, will pass through 
the principal focus of a concave mirror. 
ii) A ray passing through the principal focus of a concave mirror after 
reflection will emerge parallel to the principal axis. 
iii) A ray passing through the centre of curvature of a concave mirror 
after reflection is reflected back along the same path. 
iv) A ray incident obliquely to the principal axis towards the pole of a 
concave mirror is reflected obliquely, making equal angles with the 
principal axis. 
(any two) 1 × 2  
 
 
1 3 
    
Delhi – 31/1/3 Page 5 
 
Q17. 
 
1  
 ? Light from the Sun near the horizon passes through thicker layers of 
air and longer distance 1  
 ? Most of the blue light and shorter wavelengths of sunlight are 
scattered away by the particles. Light of larger wavelength reaches us 
giving the reddish appearance  1 3 
    
Q18.  (a) No, it pollutes air. 
 
Advantage:  
Segregation of wastes into biodegradable and non biodegradable wastes 
at the initial stage of disposal saves time and energy. 
 
(b) By putting wastes in proper dustbins 
                                                                                   Or any other 
½, ½ 
 
 
1 
 
 
1 
 
 
 
 
 
 
 
3 
    
Q19. ? For magnified erect image – Object is between the optical centre 
and principal focus of a convex lens 
½  
 
 
1  
 ? For magnified inverted image – object between F and 2F of a 
convex lens 
½  
 
 
1  
 ? cm 20 ? ? u cm 10 ? ? f ? ? v   
 
u v f
1 1 1
? ? 
½ 
 
Read More
Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

Complete Syllabus of Class 10

Dynamic Test

Content Category

Related Searches

Sample Paper

,

Extra Questions

,

Class 10

,

Semester Notes

,

Free

,

CBSE Class 10 Notes | EduRev

,

ppt

,

shortcuts and tricks

,

practice quizzes

,

Viva Questions

,

Class 10

,

CBSE Class 10 Notes | EduRev

,

pdf

,

Exam

,

Science Past Year Paper SA-2 Solution(Set -3 Outside Delhi) - 2015

,

Objective type Questions

,

video lectures

,

study material

,

Previous Year Questions with Solutions

,

Science Past Year Paper SA-2 Solution(Set -3 Outside Delhi) - 2015

,

mock tests for examination

,

Science Past Year Paper SA-2 Solution(Set -3 Outside Delhi) - 2015

,

past year papers

,

CBSE Class 10 Notes | EduRev

,

Important questions

,

Class 10

,

MCQs

,

Summary

;