CBSE Class 12 Question Paper 2026 Biotechnology

FOR CBSE CLASS 12 EXAM PREPARATION

CBSE Class 12 2026
Question Paper ·
Biotechnology
EXAM YEAR TYPE SUBJECT

CBSE Class 12 2026 Question Paper Biotechnology

Notes · Sample Papers · Previous Year Papers · Mock Tests

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Series : SRP1Q a SET ~ 4

 .
- 
Q.P. Code 99
Roll No.  -   - 
-    
Candidates must write the Q.P. Code
on the title page of the answer-book. m
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 / NOTE :
m .co s e m
 ase    -    15   l a
(I)
g l ag
a
Please check that this question paper contains 15 printed pages.
(II) -        -    -  -   
Q.P. Code given on the right hand side of the question paper should be
written on the title page of the answer-book by the candidate.
(III)       -  33   
Please check that this question paper contains 33 questions.
(IV)         , -om
. c        
  m e
las
Please write down the serial number of the question in the answer-
g
book at the given place before attempting it.
a
(V)  -     15        -     10.15
    10.15   10.30     -     
   -      
15 minute time has been allotted to read this question paper. The question
paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the
candidates will read the question paper only and will not write any answer
on the answer-book during this period. {} m
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- m
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a {ZYm©[aV g‘¶ : 3 KÊQ>o A{YH$V‘ A§H$ : 70
Time allowed : 3 hours Maximum Marks : 70

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  :

         :
(i)  -  33        
(ii) -      – -, , ,    
(iii)  –  :   1  16          1    
(iv)  –  :   17  21   -        2    
(v)  –  :   22  28  -        3    
(vi)  –  :   29  30    4        
           
(vii)  –  :   31  33  -        5    
(viii) -         ,  –        
        

 – 

1.            ,    1
(A)           
(B)            
(C)      
(D)      

2.            ()    1
(A) 30% CO2
(B) 2% CO2
(C) 5-10% CO2
(D) 15-20% CO2
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General Instructions :
Read the following instructions carefully and follow them :
(i) This Question paper contains 33 questions. All questions are compulsory.
(ii) Question paper is divided into five sections – Section A, B, C, D and E.
(iii) Section A : Questions number 1 to 16 are Multiple Choice Type Questions
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(MCQs). Each question carries 1 mark.
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(iv) Section B : Questions number 17 to 21 are Very Short Answer (VSA)
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Type Questions. Each question carries 2 marks.
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(v) Section a
C : Questions number 22 to 28 are Short Answer (SA) Type
agQuestions. Each question carries 3 marks.
(vi) Section D : Questions number 29 and 30 are Case Study-based Questions,
carrying 4 marks each. Each question has sub-parts with internal choice in
one sub-part.
(vii) Section E : Questions number 31 to 33 are Long Answer (LA) Type
Questions. Each question carries 5 marks.

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(viii) There is no overall choice given in the question paper. However, an
internal choice has been provided in few questions in all the Sections
except Section – A.
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aSECTION – A
1. The formation of inclusion bodies in microbial cell culture is associated
with : 1
(A) Incorrect folding and intracellular accumulation of recombinant
proteins.
(B) Incorrect folding and extracellular secretion of recombinant proteins.
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a 2. The incubators used to culture mammalian cells are maintained at : 1
(A) 30% CO2 (B) 2% CO2

(C) 5-10% CO2 (D) 15-20% CO2

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3.  DNA-              1
(A) c-DNA (B) 
(C) m-RNA (D) 

4.      ________       1
(A)  (B)  
(C)   (D) 

5. .         ________    1
(A) 250 mg (B) 150 mg
(C) 350 mg (D) 450 mg

6.          – 1
(A)     ()    (DNA)      
(B)       
(C)   () DNA    
(D)   DNA    

7.   ()     /  / – 1
(A)      1877 (B)      1977
(C)    1985 (D)   1973

8.            – 1
(A)       
(B)       
(C)        
(D)       

9.         1
(A)      
(B)   
(C)     
(D)    

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3. The most common molecule used to spot on a DNA microarray is : 1
(A) cDNA (B) Peptide
(C) mRNA (D) Antibody

4. Plant organ culture involves the in vitro growth of isolated _________. 1
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(A) Protoplast (B) Plant cell
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s e m
s em l a
5. a the dry cell weight of one billion cells is approximately :
For E.lcoli,
g ag 1
(A)a 250 mg (B) 150 mg
(C) 350 mg (D) 450 mg

6. The natural defence mechanism of bacteria occurs for : 1
(A) Destruction of bacteria’s own DNA during replication.
(B) Facilitating efficient cloning process.
m
(C) Destruction of invading viral DNA
.co
em
(D) Destruction of invading bacterial DNA
s
g la
7. a was developed by :
The technique of Nick Translation 1
(A) Rigby and Paul Berg in 1877 (B) Rigby and Paul Berg in 1977
(C) Linus Pauling in 1985 (D) Paul Berg in 1973

8. Locus link was primarily developed to : 1
(A) Provide three dimensional structures of proteins.
m
.co
(B) Store taxonomic information of species.
m
c. o (C) Provide information on official gene names. s e m
e m (D) Provide information on metabolic pathways.
l a
las ag
ag 9. Which of the following is a function of collagen in human body ? 1
(A) Providing strength to our bones. (B) Production of hormones.
(C) Transport of oxygen to tissues (D) Secretion of digestive enzymes

99 {} Page 5 of 16 P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 5 of 16

10.               ? 1
(A)             
(B)           
(C)        
(D)       

11.        1
(A)       
(B)     -  
(C)     -   
(D)     

12.     ()   SCID (   )    ? 1
(A)   (B) 
(C)  (D)  

  13  16  ,      –     (A)     (R)
               (A), (B), (C)  (D)   
 :
(A)  (A)   (R)      (R),  (A)   
  
(B)  (A)   (R)   ,   (R),  (A)  
    
(C)  (A)  ,   (R)   
(D)  (A)  ,   (R)   

13.  (A) :    ()        
          
 (R) :             
        1

14.  (A) :          
      
 (R) :           1

99 {} Page 6 of 16

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 6 of 16

m
m .co

m .co s e m
se g l a
a
10. Which of the following statements is correct for use in diagnostics and
therapeutics ? 1
(A) Monoclonal antibodies are preferred over polyclonal antibodies.
(B) Antibiotics are preferred over antibodies.
(C) Antibodies are not used at all.
(D) Only polyclonal antibodies are used.
m
m
11. Single Nucleotide Polymorphisms can occur : 1 .co
.co
(A) only in the coding regions of a genome.
m s e m
e
(B) only in the non-coding regions of a genome.
s l a
l a
(C) in both coding and non-coding regions of a genome.
g ag
a
(D) in mitochondrial DNA only

12. SCID (Severe Combined Immuno Deficiency) is caused due to deficiency of
which enzyme ? 1
(A) Adenosine deaminase (B) Amylase
(C) Lipase (D) Reverse Transcriptase

m
For Questions 13 to 16, two statements are given – one labelled Assertion (A)

from the options (A), (B), (C) and (D) as given below : m .co
and other labelled Reason (R). Select the correct answer to these questions

s e
g la
(A) Both Assertion (A) and Reason (R) are true and the Reason (R) is the
correct explanation of the Assertion (A).
a
(B) Both Assertion (A) and Reason (R) are true, but the Reason (R) is not
the correct explanation of the Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.

13. Assertion (A) : The human embryonic stem cells can be derived from the
inner cell mass of blastocyst and cultured in a suitable
nutrient medium. m
m .co
.co
Reason (R) : It is possible to selectively remove a gene and make
e m
precise genetic modification in mouse embryonic stem
em cells.
l as 1
s g
la 14. Assertion (A) : Mutation selection technique identifies
a micro organisms
ag
that have been improved by induced mutations.
Reason (R) : Mutations cannot be induced by irradiations in micro-
organisms. 1

99 {} Page 7 of 16 P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 7 of 16

15.  (A) : M-13  DNA      ( )
 ()     
 (R) :      DNA      
            
   1

16.  (A) :             
      
 (R) :   RNA        
          1

 – 
17. (a)    (BAC)        ?   
       2

(b)  DNA             2
5' ACTAGAATTCGCCA 3'
             ?   
             

18.            ,     
     ,  ?         
        2

19. ‘ ’ (-)     ?        
()          ? 2

     . 19  
             ? 2

20.           ?       ? 2

21.             ,        
               2

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m
m .co

m .co s e m
se g l a
a
15. Assertion (A) : M13 bacteriophage uses rolling circle mechanism for
DNA replication.
Reason (R) : During rolling circle mechanism, double stranded
replicative form of DNA is formed which replicates until
there are about its hundred copies in the host bacterial
cell. 1
m
m
16. Assertion (A) : The gene that encodes for Barnase is used to induce .co
.co
male sterility in transgenic plants.
m s e m
e
Reason (R) : Barnase is a RNA hydrolyzing enzyme that inhibits
s l a
g l a pollen formation in the tapetal cells of anther.
ag 1
a SECTION – B

17. (a) On which plasmid are Bacterial Artificial Chromosome (BAC) vectors
based ? Enlist the important sequences present in these vectors. 2
OR
(b) Given below is a single stranded sequence of DNA : 2
5' ACTAGAATTCGCCA 3'
m
.co
Which restriction enzyme would cleave this sequence in double

s em
stranded form ? Illustrate the fragments that will be generated upon
digestion by this restriction enzyme.
g la
a
18. Although not required for cell growth, antibiotics are one of the most
essential components of animal cell culture medium. Why ? Give examples
of two such antibiotics often used in animal cell culture medium. 2

19. What is meant by ‘Gene knock out’ ? How is it useful in developing mouse
models for studying human diseases ? 2

m
.co
Alternative Question for Visually Impaired in lieu of Q. No. 19.
m
.co em
Why is an inverted microscope required to observe animal cell cultures ? 2

e a s
m 20. How is chymotrypsinogen converted to chymotrypsin inlthe
l as ag duodenum ?
ag
What is the name of this process ? 2

21. Even if we know where the genes are present in a genome, it is not
entirely clear how to count them. Give two reasons for this problem. 2

99 {} Page 9 of 16 P.T.O.

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.co s e m
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 – 
22.    (  )       ()
                
      ? 3

23.               
        3

24.                ?    
     ()     3

25.               
          ()    ?   
       3

      25  
    ()              
      3

26.             
             3

27. (a) DNA            
   : 3
(i) 
(ii) 
(iii) 

(b)            -
      3

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m
m .co

m .co s e m
se g l a
a
SECTION – C

22. Briefly explain the process of sickling of Red Blood Cells (RBCs) during
sickle cell anaemia. Why does sickle celled RBCs lead to anaemic
conditions in patients ? 3

m
.co
23. How does the metagenomics approach helps to identify novel genes
m
.co
present in an environment ? Explain the process.
s e m 3

s em l a
24. What lisa the use of introducing the property of delayed fruit ripening inag
agplants ? Explain the methods used for delaying fruit ripening.
some 3

25. Mention the catalytic traid (along with diagram) which contributes to the
enzymatic activity of native subtilisin. Why was this enzyme improved by
protein engineering ? Write the method used in this process. 3

m
.co
Alternative Question for Visually Impaired in lieu of Q. No. 25
m
e
Since many centuries, whey has been used for the treatment of numerous
s
g la
ailments. Briefly elaborate upon the scientific relevance of it. 3
a
26. Selection methods are based on the expression or non-expression of
certain traits in recombinant microbial cells. Enlist such any three traits. 3

27. (a) Explain briefly the procedures of the following techniques used in
recombinant DNA Technology : 3
m
m (i) Transfection
.co
m .co (ii) Electroporation
s e m
s e (iii) Biolistics
g l a
g la OR
a
a
(b) Describe the Blue-White selection method of screening for the
presence of recombinant plasmids. 3

99 {} Page 11 of 16 P.T.O.

m .
.co s e m
s em l a
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28.         ()     
         ?         -
    3

 – 

 :   29  30  ()          [(i), (ii) 
(iii)]           
29.       (    CML)  
9    22     ()       
      (    – FISH)  
               ()   
   
(i)              1
(ii) FISH    ()  ‘der 9 ’       ?
 ? 1
(iii) (a)          2

(b) FISH   CML         ? 2

30.                 
          :
(A)  ()            
(B)  ()  ()             ()
   
(C)               
        ()       
(i) ()          1
(ii)      ‘ (Fed)’     ? 1
(iii) (a)    ()   ()   ()
    ? 2

(b)      ()     ( )
  2

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m
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a
28. How can you differentiate between cancerous and non-cancerous cells in
culture by microscopic examination ? Give one example of each of such cell
types. 3

SECTION – D

Instructions : Q. Nos. 29 and 30 are case-based questions. Each of these
m
questions have sub-parts [(i), (ii) and (iii)] with an internal choice in one
m .co
sub-part.
.co
m Chronic Mylogenous Leukemia (CML) is caused due to las e m
29. In human ebeings,
l as
the reciprocal translocation between chromosome 9 and chromosome 22.ag
a
Thisgtranslocation is detected by Fluorescence in-situ hybridisation
(FISH) technique in such patients, and severity of the disease is observed.
(i) Name the genes which fuse during translocation in Philadelphia
chromosome. 1
(ii) During FISH technique, is any fluorescence detected in the der 9
chromosome ? Why ? 1
(iii) (a) Briefly describe Nick Translation technique. 2
OR
m
(b) How is CML detected by FISH techniques ? .co 2

s em
g a
30. Microbial culture works are lclassified based on how nutrients are
a during the fermentation process as :
supplied and culture is maintained
(A) Batch Culture : This is a closed system with fixed amount of nutrient
medium.
(B) Fed-Batch culture : In this system, fresh nutrients are added during
growth, but culture is not removed.
(C) Continuous culture : This is a culture system where fresh medium
containing a limited nutrient is added when required and an equal
volume of the culture is removed.
m
m(i) Enlist any two limitations of batch culture.
c. o (ii) What does the term ‘fed’ in fed-batch culture refer to ? sem .co 1
1
s em (iii) (a) Write the significance of using a turbidostat and g l aa chemostat in
la a
ag
continuous culture system. 2
OR
(b) Draw labelled graphical representations of Batch and
continuous culture systems. 2

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.co s e m
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a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 13 of 16

 – 

31. (a)           
(MALDI)               5

(b)           ?        
             5

32. (a) (i)     - ( )      
 ?   ( )       
(ii)              
   5

(b)     ‘ ’       
           -  ‘
’       ? 5

33. (a) (i)   (   -PCR)    
   
(ii)      DNA-         10
PCR              ?  
  3+2=5

(b) ‘RFLP’    ()   ?        
      1+2+2=5
______________

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SECTION – E
31. (a) State the principle of mass spectrometry. Describe the procedure of
Matrix Assisted Laser Desorption Ionisation (MALDI), explaining
the significance of the matrix in this technique. 5
OR
m
(b)
m
Why do cereals and legumes have limited nutritional quality ?
.co
.co
Describe two genetic engineering approaches used to improve protein
s e m
em
quality in seeds.
s l5a
g la ag
a
32. (a) (i) How are virus-free plants produced from virus-infected plants ?
State any two advantages of virus-free plants. 5
(ii) Elaborate on the production of artificial seed and illustrate its
structure with a well-labelled diagram.
OR
(b) m
Explain the steps involved in the development of Golden Rice
o
. c
through genetic engineering and mention its advantages in providing
m
e further engineered ?
las
nutrition. How was Golden Rice 5

a g
33. (a) (i) Describe the steps involved in a Polymerase Chain Reaction
(PCR) technique. 3+2=5
(ii) If a researcher starts with three double stranded DNA
molecules, how many such molecules will be produced after 10
PCR cycles ? Explain briefly.
OR
o m
m What is the full form of RFLP ? State its basic principle and c
. mention
c. o (b) any s
m
e 1+2+2=5
e m two important applications.
l a
l as ____________
a g
ag

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