CBSE Class 12 Biology Exam Sample Paper for 2025-26, Obtain Model Paper PDF at No Cost
The Central Board of Secondary Education (CBSE) has released a sample paper for the Class 12 Biology exam for the academic year 2025-2026. The question paper is structured into five sections with a total of 33 questions carrying 70 marks.
The paper consists of:
- Section A: 16 questions of 1 mark each (Total 16 marks)
- Section B: 5 questions of 2 marks each (Total 10 marks)
- Section C: 7 questions of 3 marks each (Total 21 marks)
- Section D: 2 case study-based questions of 4 marks each (Total 8 marks)
- Section E: 3 long answer questions of 5 marks each (Total 15 marks)
All questions are compulsory, but some have internal choices, allowing students to answer one of the alternatives. Diagrams should be drawn wherever necessary.
In Section A, Question 1 asks about the formation of male gametes, with the correct answer being D. Meiotic division of the nucleus of the generative cell. Question 3 asks about the hormone that stimulates the formation of graafian follicles during the menstrual cycle, with the correct answer being C. FSH and LH. Question 9 asks about the correct sequence of transmission of the Plasmodium parasite, which causes malaria, but lacks sufficient context without prior knowledge. Question 1 asks about the formation of the primary endosperm nucleus, with the correct answer being B. A male gamete and two polar nuclei. Question 5 asks about short stretches of DNA used to identify complementary sequences in a sample, with the correct answer being A. Probes.
In Section B, Question 2 asks about the formation of the primary endosperm nucleus, with the correct answer being B. A male gamete and two polar nuclei. Question 5 asks about the short stretches of DNA used to identify complementary sequences in a sample, with the correct answer being A. Probes.
In Section C, Question 4 in Section-A asks about the scientists who provided experimental proof on the thermal stability of genetic material. The correct answer is C. Frederick Griffith. Question 8 asks about the expected effect of a mutant cricket with thicker hind legs on the cricket species. The correct answer is D. The leg mutation might lead to reproductive isolation and speciation due to an effect on the mating call.
In Section D, this section contains 2 case study-based questions of 4 marks each.
In Section E, this section has 3 questions of 5 marks each.
It is important to note that the pathogen in malaria, when transferred by a vector bite, is in the form of sporozoites (Option A, I). The stage of the malaria pathogen as it is transferred to a new vector is gametocytes (Option IV, IV, B). The first site in the host body where the malaria pathogen infects and proliferates is the erythrocyte (Option II, II). The second site in the host body where the malaria pathogen infects and manifests clinical symptoms is the liver (Option III, III).
In addition, practical/internal assessment carries 30 marks, separate from the theory paper of 70 marks. The sample paper is available for free for students.
Lastly, Question 7 in Section-A asks about the probability that the second child of a couple with normal skin pigmentation will be an albino if the first child was an albino. The correct answer is B. 25%. Question 6 in Section-A asks about the incorrect statement among the given options. The incorrect statement is D. The gene pool (total genes and their alleles in a population) remains constant. This is called genetic equilibrium. Sum total of all the allelic frequencies is 1.
- This comprehensive sample paper from CBSE for the Class 12 Biology exam in the academic year 2025-2026 offers online-education opportunities for students, with learning resources covering various topics like meiotic division, hormones, DNA probes, scientific breakthroughs, genetics, and malaria life cycle.
- In addition to the theory paper, which contains 70 marks, practical/internal assessment separately contributes 30 marks, providing a well-rounded education-and-self-development experience for students.
