List of top Biology Questions asked in CBSE CLASS XII

Using various resources such as your school library or the internet and discussions with your teacher trace the evolutionary stages of any one animal say horse.
Can we call human evolution as adaptive radiation?
Describe one example of adaptive radiation.
Find out through internet and popular science articles whether animals other than man have self-consciousness.
Attempt giving a clear definition of the term species
Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.
Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
What is DNA fingerprint? Mention its application.
Why is the Human Genome project called a mega project?
Explain(in one or two lines)the function of the followings:
(a)Promoter
(b)tRNA
(c)Exons
In the medium where E.coli was growing lactose was added which induce the lac operon. Then why does lac operon shut down some time after addition of lactose in the medium?

List two essential roles of the ribosome during translation.

How did Hershey and Chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?

Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesised from it (DNA or RNA), list the types of nucleic acid polymerases.

If the sequence of the coding strand in a transcription unit is written as follows: 

5-ATGCATGCATGCATGCATGCATGCATGC-3

 Write down the sequence of mRNA.

If a double standard DNA has 20 per cent of cytosine calculate the per cent of adenine in the DNA.
Who had proposed the chromosomal theory of inheritance?
What is point mutation? Give one example.
Briefly mention the contribution of T.H. Morgan in genetics.
Mention the advantages of selecting pea plant for experiment by Mendel.
How many eggs do you think were released by the ovary of a female dog which gave birth to 6 puppies?
How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?
In our society the women are often blamed for giving birth to daughters. Can you explain why this is not correct?.
What is parturition? Which hormones are involved in induction of parturition?
What is menstrual cycle? Which hormones regulate menstrual cycle?