CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D

Access and download CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D, carefully designed as per the latest 2025-26 examination guidelines issued by CBSE, NCERT, and KVS. These Class 12 Biology previous year question papers include detailed solutions, helping students to assess their performance and identify and improve key areas before the final exams.

Solved Biology Question Papers for Class 12

Practicing these Class 12 Biology question papers is the best way to understand the actual exam pattern and marking scheme. By solving these papers under timed conditions, Class 12 students can improve their speed and accuracy. Download the full CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D to begin your self-assessment today.

Biology Class 12 Question Paper PDF with Solutions

SECTION – A
1. Which one of the following is not found in a female gametophyte of an angiosperm ?
 
(a) Germ pore
 
(b) Synergids
 
(c) Filiform apparatus
 
(d) Central cell
 
2. The autosomal disorder/disease in humans is
 
(a) Colour blindness
 
(b) Thalassemia
 
(c) Haemophilia
 
(d) Turner’s Syndrome
 
3. Choose the chromosome, in a human, that possesses least number of genes.
 
(a) 21st Chromosome
 
(b) Autosome
 
(c) X-Chromosome
 
(d) Y-Chromosome
 
4. The practice of mating unrelated animals within the same breed, but with no common ancestor on either side of the pedigree for 4-6 generation is known as
 
(a) out-breeding
 
(b) out-crossing
 
(c) cross-breeding
 
(d) in-breeding 
            OR
Bacteria present in rumen of a cattle digest cellulose to produce
 
(a) Polysaccharides
 
(b) Sucrose
 
(c) Ethanol
 
(d) Methane 
 
5. It is observed that, the species diversity decreases as we
 
(a) move away from equator to poles
 
(b) move towards equator from poles
 
(c) move along the equator
 
(d) move from deserts to rain-forests. 
                        OR
CNG is preferred as a fuel over diesel for public transport because
 
(i) it is cost effective.
 
(ii) it burns almost completely.
 
(iii) it can be recycled.
 
(iv) it burns only partially.
 
Choose the correct combination.
 
(a) (i) + (ii)
 
(b) (i) + (iii)
 
(c) (ii) + (iii)
 
(d) (iii) + (iv) 
 
SECTION – B
6. Mention the advantages of emasculation and bagging in artificial hybridization in plants bearing unsexual, and bisexual flowers.
 
7. Two children one with blood group ‘AB’ and other with blood group ‘O’ are born to parents, where the father has blood group ‘A’ and the mother has blood group ‘B’. Work out a cross to show how is it possible ? 
 
8. Name the types of acquired immune responses, and the special types of lymphocytes involved in providing them.
OR
Name two organisms belonging to two different kingdoms, that are commonly used as biofertilizers, and how ? 
 
9. Write the basis of naming the restriction endonuclease EcoR-I. 
 
10. What are transgenic animals ? How was the first transgenic cow found to be more useful than the normal cow, for humans ?
 
11. How do the following organisms pull through the adverse environmental conditions ?
 
(a) Fungi
 
(b) Zooplankton
 
(c) Bear
 
(d) Snails 
 
12. (a) How many primary producers do you think would be needed to support six tertiary consumers in a grassland ecosystem ?
 
     (b) Draw a grassland pyramid to substantiate your answer.
Please click on below link to download CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D.

CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D

To understand the types of questions asked in past examinations, it is very important for Class 12 students to solve the CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D provided above. You can easily download these past papers for Class 12 Biology in PDF format for the last 10 years. By practicing these actual exam questions you will gain an understanding of the difficulty level and the variety of topics covered over the years. By solving these Previous Year Papers (PYPs) you will understand both descriptive and MCQ questions in your final tests.

Importance of solving CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D

Regularly practicing CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D is the best way to improve your score in Class 12 Biology. These papers will give you details of the marking scheme and the paper structure used by the CBSE. By regularly attempting these under actual exam conditions at home, you can slowly improve your time management skills, which will help you to complete your Biology paper within the allowed duration.

Benefits of downloading CBSE Class 12 Question Papers

Having the CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D in PDF format allows you to revise key concepts anywhere, even without an internet connection. These sets are a reliable tool to practice numerical problems and understand the correct approach to all types of answers. After solving the questions, you should compare your work with the solutions provided by our teachers. Along with these papers, students should always solve the Class 12 Biology Sample Papers and MCQ tests on studiestoday.com for a complete revision.

Where can I download the official PDF for CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D?

The CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D is available for download on StudiesToday.com. It includes complete set with all sections so that Class 12 students can practice with the exact same paper that came in the CBSE exams.

Are the solutions for CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D based on the official CBSE marking scheme?

Yes, the solutions for CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D are prepared by subject matter experts as per official marking scheme. Class 12 students will understand the structure of answers and 'step-marks' methodology Biology.

How does solving CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D help in preparing for the 2026 exams?

Solving previous year papers like CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D is important to understand repeat themes and question difficulty levels of Biology. It helps Class 12 students to test their time management skills too.

Can I access CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D in different languages?

Yes, where applicable, CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D is available in both English and Hindi mediums. All students from Class 12 can access Biology study material in their preferred language.

Is there a charge to download the CBSE Class 12 Biology solved papers?

No, all previous year question papers on StudiesToday, including CBSE Class 12 Biology Boards 2020 Question Paper Solved Set D, are provided free of charge in mobile-friendly PDF.