CBSE 12 Biology 2025 Answer Key: The CBSE Class 12 Biology Exam 2025 was held today, March 25, by the Central Board of Secondary Education (CBSE) from 10:30 AM to 1:30 PM. The Class 12 Biology exam is designed to evaluate students' conceptual understanding, application skills, and analytical thinking in biological concepts. It is crucial for students aspiring to pursue careers in medical sciences, biotechnology, and allied fields. After the board exam, students are now searching for the CBSE Class 12 Biology Answer Key to check the correct answers, review their performance, and estimate their scores before the official results. Stay tuned for the CBSE 12th Biology 2025 Answer Key, prepared by experts.
CBSE Class 12 Biology Set 3 Answer Key
| CBSE 12 Biology Set 3 Code 57/2/3 Answer Key | ||
|---|---|---|
| Section | Question Number | Answer |
| A | 1 | A) Both Autogamy and Geitonogamy |
| 2 | D) I - Spermatogonia, II - Sec. Spermatocyte, III - Spermatid, IV - Spermatozoa | |
| 3 | A) (iii), (i), (ii), (iv) | |
| 4 | B) Francis Crick | |
| 5 | D) 7, 8 | |
| 6 | B) (ii) and (iii) | |
| 7 | B) (a) (i), (b) (iii), (c) (ii) | |
| 8 | C) IBi IAIB IAi | |
| 9 | B) decrease in antibodies | |
| 10 | B) 0:1:3 | |
| 11 | D) Plasmid DNA acts as a vector to transfer the piece of DNA attached to it | |
| 12 | A) Aspergillus niger | |
| 13 | A) Both (A) and (R) are true and (R) is the correct explanation of (A). | |
| 14 | C) (A) is true, but (R) is false. | |
| 15 | A) Both (A) and (R) are true and (R) is the correct explanation of (A). | |
| 16 | C) (A) is true, but (R) is false. | |
Also Check,
NEET UG Exam Date 2025 OUT, Check Shift Timings and Other Details
NEET UG Syllabus 2025; Check Subject-wise Important Topics
CBSE Class 12 Biology Set 2 Answer Key
| CBSE 12 Biology Set 2 Code 57/1/2 Answer Key | ||
|---|---|---|
| Section | Question Number | Answer |
| A | 1 | A) Soil A has a slower rate of decomposition than Soil B. |
| 2 | C) 25 to 50 micrometer | |
| 3 | C) Menstrual phase, Follicular phase, Ovulatory phase, Luteal phase | |
| 4 | D) Phenotypes = 4; Genotypes = 9 | |
| 5 | A) Preventing the process of translation of mRNA of the nematode. | |
| 6 | B) 5'-AAUGCUAGGCAC - 3' | |
| 7 | C) 50% | |
| 8 | B) Australopithecines → Homo erectus → Neanderthal → Homo sapiens | |
| 9 | D) Genetic Engineering Approval Committee | |
| 10 | D) Cell mediated immune response | |
| 11 | 1 trillion times | |
| 12 | B) P: Zygote, Q: Suspensor, R: Cotyledon, S: Plumule | |
| 13 | A) Both (A) and (R) are true and (R) is the correct explanation of (A). | |
| 14 | C) (A) is true, but (R) is false. | |
| 15 | A) Both (A) and (R) are true and (R) is the correct explanation of (A). | |
| 16 | B) (A) is true, but (R) is false. | |
CBSE Class 12 Biology Set 1 Answer Key
|
Section |
Question Number |
Answer |
|
A |
1 |
|
|
2 |
||
|
3 |
||
|
4 |
||
|
5 |
||
|
6 |
||
|
7 |
||
|
8 |
||
|
9 |
||
|
10 |
||
|
11 |
||
|
12 |
||
|
13 |
||
|
14 |
||
|
15 |
||
|
16 |
||
|
B |
17 |
|
|
18 |
||
|
19 |
||
|
20 |
||
|
21 |
||
|
C |
22 |
|
|
23 |
||
|
24 |
||
|
25 |
||
|
26 |
||
|
27 |
||
|
28 |
||
|
D |
29 |
|
|
30 |
||
|
E |
31 |
|
|
32 |
||
|
33 |
CBSE Board Class 12 Biology Answer Key 2025
Students can download the CBSE Board Class 12 Biology Answer Key 2025 from the links below to cross-check their answers and calculate their expected marks.
|
Set Number |
Answer Key PDF Link |
|
Set 1 |
Download here |
|
Set 2 |
|
|
Set 3 |
Download here |
CBSE Class 12 Biology Exam 2025: Overview
|
Conducting Body |
CBSE |
|
Mode of Exam |
Pen and Paper (Offline) |
|
Duration |
3 hours |
|
Marks |
70 |
|
Total Number of Questions |
33 |
|
Section |
5 (A, B, C, D and E) |
|
Question Type |
|
CBSE Class 12 Biology Paper Format 2025
The CBSE Class 12 Biology question paper is structured into different sections based on difficulty level and types of questions. The exam is divided into five sections and contains 33 questions. All questions are compulsory, with no overall choice. However, internal choices are available within specific sections. The details CBSE Class 12 Biology Board Exam Pattern is given below:
| Section | Number of Questions | Marks/Question | Total Marks |
|---|---|---|---|
| Section A (Q.1 - Q.16) | 16 | 1 | 16 |
| Section B (Q.17 - Q.21) | 5 | 2 | 10 |
| Section C (Q.22 - Q.28) | 7 | 3 | 21 |
| Section D (Q.29 - Q.30) | 2 | 4 | 8 |
| Section E (Q.31 - Q.33) | 3 | 5 | 15 |
CBSE 12th Biology Marking Scheme
The CBSE Class 12 Biology Board Exam Marking Scheme ensures a fair evaluation by incorporating stepwise marking for problem-solving questions. Below is the detailed section-wise marking distribution.
- Section A- 16 MCQs and A&R of 1 mark each
- Section B- 5 VSA Questions of 2 marks each
- Section C- 7 SA Questions of 3 marks each
- Section D- 2 Case Study-based Questions of 4 marks each each
- Section E- 3 LA Questions of 5 marks