CBSE Class 12 Biology Compartment Set 2 - (57/7/2) Question Paper 2026 is available for download here. CBSE conducted the Class 12 Biology Compartment (supplementary) examination on July 28, 2026, from 10:30 AM to 1:30 PM. The Biology paper is of 70 marks and the time allowed is 3 hours. This paper carries the Q.P. code 57/7/2 and is of Set 2. The question paper was handed out at 10:15 AM, and the first 15 minutes were given for reading it.

Also Check: CBSE Class 12 Question Paper 2026 (All Subjects)

The paper has 33 questions in five sections, A to E, and all questions are compulsory:

  • Section A has 16 multiple choice questions of 1 mark each
  • Section B has 5 very short answer questions of 2 marks each
  • Section C has 7 short answer questions of 3 marks each
  • Section D has 2 case-based questions of 4 marks each
  • Section E has 3 long answer questions of 5 marks each
  • There is no overall choice, but an internal choice is given in Sections B, D and E
  • Neat and properly labelled diagrams should be drawn wherever necessary

CBSE Class 12 Biology Compartment Set 2 - (57/7/2) Question Paper 2026 PDF

CBSE Class 12 Biology Compartment 2026 Set 2 (57/7/2) Questions with Solutions

Question 1:

The path of the sperm transport is shown below. Identify P and Q and select the correct option.

Seminiferous tubules→Rete testis→P→Epididymis→Q→Urethra

  • (A) P - Vasa efferentia, Q - Ureter
  • (B) P - Ejaculatory duct, Q - Vas deferens
  • (C) P - Vasa efferentia, Q - Vas deferens
  • (D) P - Vas deferens, Q - Vasa efferentia

Question 2:

Failure of segregation of chromatids during cell division results in gain or loss of chromosomes. Select the correct option.

  • (A) Euploidy
  • (B) Monoploidy
  • (C) Aneuploidy
  • (D) Polyploidy

Question 3:

Polyembryony commonly occurs in which one of the following plants ?

  • (A) Banana
  • (B) Tomato
  • (C) Potato
  • (D) Citrus

Question 4:

Choose the right option that indicates the safe period for medical termination of pregnancy.

  • (A) Second trimester of pregnancy
  • (B) 12 weeks of pregnancy
  • (C) 5 months of pregnancy
  • (D) 21 weeks of pregnancy

Question 5:

When an amino acid is coded by more than one codon, the genetic code is said to be :

  • (A) Universal
  • (B) Punctuated
  • (C) Commaless
  • (D) Degenerate

Question 6:

Miller's experiment included some gases in his experiment. Which of the following gas was not part of his experiment ?

  • (A) Methane
  • (B) Hydrogen
  • (C) Ammonia
  • (D) Carbon dioxide

Question 7:

Polio vaccine provides which kind of immunity in children ? Select the correct option.

  • (A) Innate immunity
  • (B) Passive immunity
  • (C) Autoimmunity
  • (D) Active immunity

Question 8:

A person admitted to hospital as he had myocardial infarction. A cardiologist injected him 'streptokinase'. Select the option that indicates the correct reason for using streptokinase.

  • (A) It stimulates the heartbeat.
  • (B) It reduces hypertension.
  • (C) It acts as a clot-buster.
  • (D) It reduces the level of blood cholesterol.

Question 9:

Significance of heat shock method in bacterial transformation is to facilitate which one of the following steps ?

  • (A) Binding DNA to the cell wall
  • (B) Uptake of DNA through membrane transport proteins
  • (C) Uptake of DNA through transient pores in the bacterial cell wall
  • (D) Expression of antibiotic resistance genes

Question 10:

Cry proteins coded by the gene Cry IAb controls which one of the following pests ?

  • (A) Cotton bollworm
  • (B) Corn borer
  • (C) Tobacco budworm
  • (D) Mosquito

Question 11:

In spite of interspecific competition in nature, which of the following mechanisms might competing species have evolved to coexist and survive ?

  • (A) Competitive exclusion
  • (B) Competitive release
  • (C) Resource partitioning
  • (D) Co-evolution

Question 12:

Which of the following groups of animals has a large number of endemic species in the western ghats ?

  • (A) Mammals
  • (B) Reptiles
  • (C) Amphibians
  • (D) Birds

Question 13:

Assertion (A) : Innate immunity is a non-specific type of defence.
Reason (R) : Skin in our body is the main physical barrier which prevents entry of microorganisms.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but 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.

Question 14:

Assertion (A) : Chemically synthesised oligonucleotides are used during annealing in PCR technique.
Reason (R) : The primers bind to the double stranded DNA at their complementary regions.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but 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.

Question 15:

Assertion (A) : Vector DNA and foreign DNA are cut by the same restriction enzyme.

Reason (R) : Vector DNA and foreign DNA, cut with same enzyme, produces complimentary sticky ends.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation for Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation for Assertion (A).
  • (C) Assertion (A) is true, but Reason (R) is false.
  • (D) Assertion (A) is false, but Reason (R) is true.

Question 16:

Assertion (A) : Endosperm in angiosperm is a triploid tissue.
Reason (R) : Endosperm is formed after triple fusion i.e. fusion, of a diploid secondary nucleus with a haploid male gamete.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but 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.

Question 17:

(i) Where do the signals for parturition originate from, in humans ?

(ii) Why is it important to feed newborn babies on colostrum ?


Question 18:

How is GIFT different from ZIFT ?


Question 19:

Name the scientist who proposed the central dogma in molecular biology. Give its schematic representation.


Question 20:

Write four criteria to be fulfilled by a molecule to act as a genetic material.


Question 21:

(a) Define stratification in an ecosystem.

(b) How is stratification represented in a forest ecosystem ?


Question 22:

(i) Name the source plant of heroin drug. How is it obtained from the plant ?

(ii) Write the effects of heroin on the human body.


Question 23:

What is "withdrawal syndrome" ? List any two symptoms it is characterised by.


Question 24:

How can childless couples get help by the following assisted reproductive technologies ?

(a) GIFT

(b) ICSI


Question 25:

Name the hormones secreted :

(a) by corpus luteum and placenta (any two), and

(b) during parturition.

Also write their functions.


Question 26:

(a) Draw a schematic representation of the structure of a transcription unit and show the following in it :

(i) Direction in which transcription occurs

(ii) Polarity of the two strands involved

(iii) Template strand

(iv) Terminator

(b) Mention the function of promoter in transcription.


Question 27:

(a) How does the human body respond to an allergen ? Which type of antibody is produced during allergic reactions ?

(b) Name the types of drugs that help in reducing the symptoms of allergic reactions.

(c) Name the chemicals released in the body during an allergic reaction.


Question 28:

Explain the Hardy-Weinberg principle with the help of an algebric equation.


Question 29:

(a) Name the type of interaction seen in each of the following examples.

(i) An orchid growing on branch of mango tree

(ii) Wasp pollinating fig inflorescence

(b) Also explain the above interactions shown by (i) and (ii).


Question 30:

"Indo-Burma" is considered as a hotspot. What is meant by the term "hotspots" in biodiversity ? List two criteria used for determining a "hotspot". Name any two hotspots of India.


Question 31:

Explain any three different approaches used in the treatment of a person suffering from Adenosine Deaminase deficiency.


Question 32:

Read the following passage and answer the questions that follow :
Sewage is generated in large quantities in the urban areas. It is treated in sewage treatment-plants (STPs) to make it less polluted before discharging into any natural water body. Observe the flow chart given below and answer the questions that follow :

Primary effluent is passed into large aeration tank

↓

Effluent is passed into settling tank to form the sediment (activated sludge)

(a) Name the two products obtained after primary treatment of sewage.


Question 33:

Read the following passage and answer the questions that follow :
Sewage is generated in large quantities in the urban areas. It is treated in sewage treatment-plants (STPs) to make it less polluted before discharging into any natural water body. Observe the flow chart given below and answer the questions that follow :

Primary effluent is passed into large aeration tank

↓

Effluent is passed into settling tank to form the sediment (activated sludge)

(b) What happens to the activated sludge when it is passed into an anaerobic sludge digester ? Explain.


Question 34:

Read the following passage and answer the questions that follow :
Sewage is generated in large quantities in the urban areas. It is treated in sewage treatment-plants (STPs) to make it less polluted before discharging into any natural water body. Observe the flow chart given below and answer the questions that follow :

Primary effluent is passed into large aeration tank

↓

Effluent is passed into settling tank to form the sediment (activated sludge)

(c) (i) Name the two groups of microbes present in the primary effluent after it is passed into large aeration tanks.


Question 35:

Read the following passage and answer the questions that follow :
Sewage is generated in large quantities in the urban areas. It is treated in sewage treatment-plants (STPs) to make it less polluted before discharging into any natural water body. Observe the flow chart given below and answer the questions that follow :

Primary effluent is passed into large aeration tank

↓

Effluent is passed into settling tank to form the sediment (activated sludge)

(c) (ii) Define BOD. What happens to the BOD when organic matter present in the wastewater increases ?


Question 36:

Read the following passage and answer the questions that follow :
Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow :

(a) Analyse the given pedigree chart to explain why Haemophilia is considered a sex-linked recessive disorder.




Question 37:

Read the following passage and answer the questions that follow :
Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow :

(b) (i) The possibility of a human female becoming a haemophilic is extremely rare. Explain.

(ii) Why do the sons of a haemophilic father never suffer from this disease ?




Question 38:

Read the following passage and answer the questions that follow :
Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow :

(c) (i) Write the possible genotype of the individuals 2 and 5.




Question 39:

Read the following passage and answer the questions that follow :
Haemophilia is a sex-linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow :

(c) (ii) Why is haemophilia categorised as a Mendelian disorder ?




Question 40:

(a) Draw a flow chart to show hormonal control of the human male reproductive system.


Question 41:

(b) Explain the changes that the primary oocyte undergoes while in different follicular stages before ovulation.


Question 42:

(I) (i) State the role of selectable markers in rDNA technology.

(ii) Name two such selectable markers which are considered to be useful for E. coli cloning vector.

(iii) State two significances of "Ori" in E. coli cloning vector.

(II) How have biotechnologists effectively used Agrobacterium tumefaciens in plants and retroviruses in animals ? Explain.


Question 43:

Name and describe the technique that helps in separation and isolation of DNA fragments after cutting of DNA by restriction endonucleases.


Question 44:

(i) How and why is charging of tRNA essential in the process of translation ?

(ii) State the function of ribosome as a catalyst in translation in bacteria.

(iii) Explain the process of binding of ribosomal units to mRNA during protein synthesis.

(iv) Where are untranslated regions located in mRNA ? Mention their role.


Question 45:

(i) State the arrangement of different genes, that in bacteria is referred to as "operon".

(ii) Draw a schematic labelled illustration of lac operon in a switched on state.

(iii) Describe the role of lactose in lac operon.

CBSE Class 12 Biology Compartment 2026 Set 2 - (57/7/2) Exam Pattern and Marking Scheme

Section Questions Question Type Marks per Question Marks
A Q1 - Q16 Multiple choice questions 1 16
B Q17 - Q21 Very short answer type 2 10
C Q22 - Q28 Short answer type 3 21
D Q29 - Q30 Case-based questions 4 8
E Q31 - Q33 Long answer type 5 15
Total 33 questions 70

CBSE Class 12 Biology Compartment 2026 Set 2 - (57/7/2) Question Paper FAQs

Ques. How many questions are there in the CBSE Class 12 Biology Compartment 2026 paper (Set 2 - 57/7/2)?

Ans. The paper has 33 questions in five sections (A to E) and all of them are compulsory.

Ques. How are the marks divided in the Biology Compartment 2026 paper?

Ans. Section A carries 16 marks, Section B 10 marks, Section C 21 marks, Section D 8 marks and Section E 15 marks, for a total of 70 marks.

Ques. Is there any internal choice in the paper?

Ans. There is no overall choice. An internal choice is given in Sections B, D and E, and a candidate writes only one of the alternatives.

Ques. Where can I download the solutions of this paper?

Ans. The table above has the Collegedunia PDF of this paper with detailed solutions.

Ques. How much time is given for the CBSE Class 12 Biology Compartment 2026 paper?

Ans. The paper is of 3 hours (10:30 AM to 1:30 PM). The question paper is distributed at 10:15 AM and candidates get 15 minutes to read it before they start writing.

Ques. When was the CBSE Class 12 Biology Compartment 2026 exam held?

Ans. The Class 12 compartment (supplementary) paper of Biology was held on July 28, 2026.

Ques. Where can I get the official CBSE Class 12 Biology Compartment question paper?

Ans. The official question papers are published on the CBSE website, cbse.gov.in.