List of top Biology Questions asked in CBSE CLASS XII

Name the (i) ape-like (ii) man-like primates that existed 1.5 million years ago.
Whose skulls ‘A’, ‘B’, and ‘C’ are shown below? Which of the two are more similar to each other?
Identify the growth curves ‘A’ and ‘B’.
Write the number of RNA polymerases involved in the transcription of DNA in a prokaryote and eukaryotes.
Mention what does the dotted line in the graph indicate and state its importance also.
Name the human body organ affected by the consumption of these drugs.
Write the ‘palindrome’ recognized by EcoRI.
Production of Biological Products:
How are such drugs consumed?
Studying Diseases:
Where does EcoRI cut the palindrome? Write the events followed thereafter to form a recombinant DNA.
Chemical Safety Testing:
Name ‘A’ and ‘B’ fragments.
Name any two hotspots in India.
Name the group of drugs whose skeletal molecule is shown below:
With reference to flower color, two independent crosses were made, one between true breeding garden pea plants and another between true breeding Antirrhinum plants. Write the phenotypes of their F$_1$ progeny. Justify your answer giving reasons.
Explain Brood parasitism with the help of a suitable example.
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.
Differentiate between grazing food chain and detritus food chain.
Draw a well-labelled diagram of the sectional view of a male gametophyte/microspore of an angiosperm and write the functions of any two parts labelled. (Any four labels).
What is artificial insemination in ART? Under what conditions is the person medically advised to go for it?
Why does a patient of ADA-deficiency require repeated infusions of genetically engineered lymphocytes? Suggest a possible permanent remedy.
Assertion (A): Plasmids are autonomously replicating circular extra-chromosomal DNA.
Reason (R): Plasmids are usually present in eukaryotic cells.
Assertion (A): A given fig species can be pollinated only by its partner wasp.
Reason (R): The wasp pollinates the fig inflorescence while searching for suitable egg-laying sites.
Assertion (A): Patents are granted by governments to an inventor.
Reason (R): Patents prevent others from commercial use of an invention.