List of top Questions asked in CBSE CLASS XII

Which one of the two curves is more “realistic” and why?
Which of the two curves is relevant in present days with respect to human population in our country and why?
‘A proper understanding of the menstrual cycle can help immensely in family planning.’ Do you agree with the statement? Provide reasons for your answer.
Why does endosperm development precede embryo development in angiosperm seeds? State the role of endosperm in mature albuminous seeds.
Draw a labelled diagram showing the different embryonic stages of a dicot plant, up to a fully mature embryo.
Describe the life cycle of HIV from the time of its entry into the human body till full-blown AIDS sets in.
Write the symptoms of malaria in humans and explain what causes these symptoms.
Whose skulls ‘A’, ‘B’, and ‘C’ are shown below? Which of the two are more similar to each other?
Name the (i) ape-like (ii) man-like primates that existed 1.5 million years ago.
Name this RNA product transcribed from the DNA that subsequently translates into a polypeptide of 400 amino acids. Mention the enzyme responsible for transcribing this type of RNA from the DNA.
Name and explain the process the RNA molecule transcribed from 8000 nucleotide-long DNA undergoes to be able to translate a polypeptide of 400 amino acids.
Write the number of RNA polymerases involved in the transcription of DNA in a prokaryote and eukaryotes.
Identify the growth curves ‘A’ and ‘B’.
Mention what does the dotted line in the graph indicate and state its importance also.
How are such drugs consumed?
Name the human body organ affected by the consumption of these drugs.
Production of Biological Products:
Studying Diseases:
Chemical Safety Testing:
Name ‘A’ and ‘B’ fragments.
Write the ‘palindrome’ recognized by EcoRI.
Where does EcoRI cut the palindrome? Write the events followed thereafter to form a recombinant DNA.
Study the graph given below that represents the changes in the thickening of the uterine wall in women ‘X’ and women ‘Y’ over a period of one month:
What does the graph with respect to women ‘X’ and woman ‘Y’ indicate? Give a suitable reason.
Name any two hotspots in India.
Differentiate between grazing food chain and detritus food chain.