List of top Questions asked in CBSE CLASS XII- 2026

Conjuguez le verbe : Aussitôt que le scientifique (finir) le discours, tout le monde a applaudi.
Conjuguez le verbe : Si j'avais du temps, je (faire) un tour du monde.
Conjuguez le verbe : (Sortir) d'ici! Il y a un feu dans la forêt !
Conjuguez le verbe : Le professeur exige que nous (étudier) régulièrement.
Sujet : Rédigez une lettre décrivant votre ville préférée. (Environ 80 mots)
Sujet : Vous écrivez à votre cousin(e) décrivant une fête à l'école. (Environ 80 mots)
Sujet : Vous écrivez à votre ami(e) pour lui décrire un voyage dans les montagnes. (Environ 80 mots)
How many Faradays are required to reduce 1 mol of \( Cr_2O_7^{2-} \) to \( Cr^{3+} \) in acidic medium?
What is the full form of RFLP? State its basic principle and mention any two important applications.
How are virus-free plants produced from virus-infected plants? State any two advantages of virus-free plants.
Elaborate on the production of artificial seed and illustrate its structure with a well-labelled diagram.
Explain the steps involved in the development of Golden Rice through genetic engineering and mention its advantages in providing nutrition. How was Golden Rice further engineered?
Describe the steps involved in a Polymerase Chain Reaction (PCR) technique.
If a researcher starts with three double stranded DNA molecules, how many such molecules will be produced after 10 PCR cycles? Explain briefly.
Why do cereals and legumes have limited nutritional quality? Describe two genetic engineering approaches used to improve protein quality in seeds.
State the principle of mass spectrometry. Describe the procedure of Matrix Assisted Laser Desorption Ionisation (MALDI), explaining the significance of the matrix in this technique.
Write the significance of using a turbidostat and a chemostat in continuous culture system.
Draw labelled graphical representations of Batch and continuous culture systems.
What does the term 'fed' in fed-batch culture refer to?
What does the term 'fed' in fed-batch culture refer to?
Write the significance of using a turbidostat and a chemostat in continuous culture system.
Draw labelled graphical representations of Batch and continuous culture systems.
Describe the Blue-White selection method of screening for the presence of recombinant plasmids.
How can you differentiate between cancerous and non-cancerous cells in culture by microscopic examination? Give one example of each of such cell types.
Name the genes which fuse during translocation in Philadelphia chromosome.