CBSE Class 12 Biology Viva Questions with Answers 2025

CBSE Class 12 Biology Viva Questions with Answers 2025: While examiners can ask anything from the syllabus, some important questions are frequently asked during the CBSe class 12th biology viva. Hence, students must prioritise these questions and study them thoroughly.

CBSE Class 12 Viva exam refers to an oral examination conducted as part of the practical assessment to evaluate a student's understanding of biological concepts in real-world settings. The viva component is of a total of 4 marks out of 30 marks under the practical assessment component. Through the viva exam, the examiner will ask a series of CBSE Class 12 Viva Questions, and students are assessed based on their answers to these questions.

CBSE Class 12 Biology Viva Questions with Answers 2025 must be prepared by all the students appearing for the CBSE Biology practical examination in session 2025. The viva for CBSE 12th board exam will be conducted on the class record and the experiments conducted in the practical examination. The students must thoroughly know the experiments and the concepts. The PDFs containing the important CBSE Class 12 Biology Viva Questions and answers can be found in this article.

CBSE Class 12 Biology Viva Questions with Answers 2025

Viva is an important component included in CBSE Class 12th Biology Syllabus 2025. The most commonly asked CBSE class 12 biology viva questions with Answers 2025 have been shared below. The students can refer to these while preparing for the viva of CBSE Biology practical examination.

1. What is the difference between DNA and RNA?

• DNA: Deoxyribonucleic acid, double-stranded, contains deoxyribose sugar, bases: Adenine, Thymine, Guanine, Cytosine.
• RNA: Ribonucleic acid, single-stranded, contains ribose sugar, bases: Adenine, Uracil, Guanine, Cytosine.

2. What is the role of enzymes in digestion?

Enzymes act as biological catalysts, speeding up chemical reactions in the digestive system. For example, amylase breaks down carbohydrates, protease breaks down proteins, and lipase breaks down fats.

3. Explain the process of photosynthesis.

Photosynthesis is the process by which green plants convert light energy into chemical energy, using carbon dioxide and water to produce glucose and oxygen.

4. What is the difference between mitosis and meiosis?

Mitosis produces two identical daughter cells, occurs in somatic cells, and involves one cell division. On the other hand, Meiosis produces four genetically different daughter cells (gametes), occurs in reproductive cells, and involves two cell divisions.

5. What is the role of the endocrine system?

The endocrine system is responsible for producing hormones that regulate various bodily functions, such as growth, development, metabolism, and reproduction.

6. What are the different types of blood groups?

The ABO blood group system has four main types: A, B, AB, and O. Each type is determined by the presence or absence of specific antigens on the surface of red blood cells.

7. What is the function of the nervous system?

The nervous system is responsible for receiving, processing, and transmitting information throughout the body, allowing for communication between different parts of the body and the external environment.

8. What is the difference between a virus and a bacterium?

• Virus: Non-living, acellular, requires a host cell to reproduce, can cause infections like influenza and HIV.
• Bacterium: Living, unicellular organism, can reproduce independently, can cause infections like pneumonia and tuberculosis.

9. What is the role of the immune system?

The immune system is responsible for protecting the body from infections and diseases by recognizing and destroying foreign substances, such as bacteria, viruses, and toxins.

10. What is the difference between aerobic and anaerobic respiration?

Aerobic respiration requires oxygen, produces more energy (ATP), and occurs in the mitochondria. While, Anaerobic respiration does not require oxygen, produces less energy (ATP), and occurs in the cytoplasm.

Q11. What is an enzyme?

Ans: An enzyme is a substance that catalyses cell metabolism.

Q12. What is protein? How many kinds of proteins are there?

Ans: Protein is the fundamental component in living cells. It is made up of hydrogen, carbon, nitrogen, oxygen, and chains of amino acids. Three types of proteins are there which include fibrous, membrane, and globular.

Q13. What is nucleic acid?

Ans: Nucleic acid is a biomolecule which is necessary for all the known forms of life.

Q14. What is a monosaccharide?

Ans: Glucose and fructose are monosaccharides.

Q15. Give a few examples of High Protein Foods?

Ans: Pumpkin seeds, Monkfish, Cod, Coconut, Eggs, Bananas.

Q16. Give the full form of DNA?

Ans: Deoxyribonucleic acid.

Q17. Why is meiosis known as reduction division?

Ans: Meiosis is also known as reduction division as following the first meiotic division the number of chromosomes in the cell becomes half.

Q18. What is the full form of RNA?

Ans: Ribonucleic acid.

Q19. Name 2 xerophytic plants.

Ans: Ephemeral Annuals and Succulent

Q20. What are Mendel’s laws of inheritance?

Ans: Mendel’s laws of inheritance include the law of segregation, law of dominance, and law of independent assortment.

Q21. What are the contrasting features that Mendel observed in a pea plant.

Ans: The contrasting features are the colour of the cotyledons, the form of seed, the form of pod, the colour of the seed coat, the length of the stem, the position of the flower, and the colour of the pod.

Q22. Who coined the term mitosis?

Ans: Walther Flemming

Q23. Name two plants and two animals living under aquatic conditions

Ans: Lilly and water hyacinth are aquatic plants. Seals and octopuses are aquatic animals.

Q24. Explain Meiosis.

Ans: Meiosis is a process in which a single cell divides two times to form four haploid daughter cells. Meiosis has 2 stages in all.

Q25. How does the hibiscus flower pollinate?

Ans: The pollen grains in Hibiscus germinates on stamen. It is then transferred from the stamen to the stigma pads of the pistil.

Q26. What is the shape of a pollen grain?

Ans: The shape of the pollen grain is mostly round, ovule, triangular, disc or in a bean-shape with a smooth to spiky texture.

Q27. Name 4 types of diseases.

Ans: Deficiency diseases, Infectious diseases, physiological diseases, hereditary diseases.

Q28. What are pollen grains?

Ans: They are small collections of microspores that aid in fertilisation and sexual reproduction in plants. It is attached to the anther of the male reproductive organ of the plant.

Q29. What is somatic cell division?

Ans: Somatic cell division is the type of cell division where the daughter cells produced are exactly similar to the parent cell. They have the same chromosomal number as the parent cell.

Q30. What are enzymes?

Ans: They are substances produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

Q31. What is meant by mitosis?

Ans: It is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

Q32. What is the pH of soil?

Ans: The optimal pH range of the soil is between 5.5 to 7.0.

Q33. Which type of soil is most favourable for the growth of plants?

Ans: Loamy soil is best for plant growth as it has high water retention capacity thus it retains water for long and also retains the nutrients which are required for plant growth.

Q24. What is meant by soil texture?

Ans: Soil texture refers to the proportion of sand, silt and clay sized particles that make up the mineral fraction of the soil. 

Q35. What is a flower's male part called?

Ans: Stamen

Q36. Define pollination.

Ans: Pollination is the act of transferring pollen grains from the male anther of a flower to the female stigma.

Q37. Pollen is contained in which part of the flower?

Ans: Anther

Q38. What produces the female gamete?

Ans: Ovule

Q39. What are the various kinds of soil?

Ans: Clay, Loamy, Sandy and Silt.

Marks Distribution for CBSE Class 12 Biology Viva Questions 2025

While it is important to look at the CBSE class 12 biology viva questions with answers 2025, it is equally important to look at the marks distribution for the same. Here is the section-wise marking scheme for CBSE class 12 biology viva.

Also Check: CBSE Class 12 Previous Year Question Papers

Best Books for CBSE Class 12 Biology Viva Questions with Answers 2025

Students must ensure studying from reliable sources to ensure updated curriculum and higher marks. While the primary source of information must be the official syllabus prescribed by the Central Board of Education (CBSE), students can also use the following books for CBSE class 12 biology viva questions with answers 2025.

• Practical Skills In Biology Class 12 Experiments, Projects, Viva Voce - CBSE - Examination 2023-2024
• Laboratory Manual Biology Class 12th [Experiments |Viva-Voce] - COMBO
• Biology Lab Manual Class 12 |Viva-voce Questions |Lab Experiments |Investigatory Projects| with latest Syllabus prescribed by CBSE - Blueprint Education
• CBSE Class 12 Biology Lab Manual with Viva Voice Question and Answer (Sahitya Bhawan)
• Laboratory Manual Biology CBSE Class-12 Experiments Projects Viva-voce (by Arihant)

Also Check: CBSE Class 12 Question Bank - All Subjects PDF Download

Preparation Tips for CBSE Class 12 Biology Viva Questions 2025

It is a great practice to look at the CBSE class 12 biology viva questions with answers 2025 and a set of preparation tips will make it even better. So, here is a list of tips for students preparing for the CBSE class 12 biology viva questions 2025.

• Thorough knowledge of the subject

It is important to have a good knowledge of the subject entirely. Two experiments are to be conducted by the students in the examination hall. The questions will be based on these experiments. It is therefore crucial that the students know the topics on which the experiments are given.

• Summarising the projects

Questions in the viva voce are also asked based on the investigatory project. Questions on the methods used in the investigatory project, the handling of data, etc., are asked.Thus, the students must prepare themselves well for such questions while working on the project.

• Answering the questions concisely

It is better not to get into a detailed description while answering the questions in viva, unless asked. Keeping it concise and to the point is the key to score good in the viva.