List of top Biology Questions

Assertion (A): Saheli is the World’s first non-steroidal oral contraceptive pill.
Reason (R): It has been developed by National Institute of Immunology, New Delhi.
RNA interference (RNAi) helps in making tobacco-plant resistant to a nematode (Meloidogyne incognita). Choose the correct option that shows how RNAi is achieved:
Evolution of modern man involves the following man-like primates. Choose the correct series of human evolution:
How many pollen grains and ovules are likely to be formed in the anther and ovary of an angiosperm bearing 50 microspore mother cells and 50 megaspore mother cells respectively?

The sequence of nitrogenous bases in a segment of a coding strand of DNA is 
5' – AATGCTAGGCAC – 3'. Choose the option that shows the correct sequence of nitrogenous bases in the mRNA transcribed by the DNA.

Amplification of gene of interest by using DNA polymerase may go up to:

Identify the labelled parts P, Q, R, and S in the stages of a dicot embryo shown in the diagram.

Choose the option that indicates correct labelling of 'P', 'Q', 'R', and 'S' of embryo in different stages of its development.

Match the following items of Column-I with that of Column-II:

Transplantation of tissues/organs to some patients often fails due to rejection by the body of the patient. Which type of immune response is responsible for such rejections?
The process of mineralization by microorganisms helps in the release of:

Match the items in Column-A with that of Column-B:

GEAC stands for
A man whose father was colour-blind marries a woman who had a colour-blind mother and normal father. What percentage of male children of this couple will be colour-blind?
Student to attempt either option (A) or (B): (A) What is meant by ‘right’ and ‘wrong’ type of pollen when pollen lands on the stigma? A two-celled right type pollen has landed on the stigma. Explain the events taking place till fertilization in angiosperms. Why is pollen pistil interaction said to be dynamic?
OR
(B)
  • Give the schematic representation of oogenesis in human females indicating chromosome number at each step.
  • In which part of the female reproductive system do the following events take place?
    • I. Formation of corpus luteum
    • II. Maturation of tertiary follicle
    • III. Fertilisation
    • IV. Implantation
A person is suffering from high grade fever. Which symptoms will help to identify if he/she is suffering from Typhoid, Pneumonia or Malaria?
  • Why are transgenic animals so called?
  • With the help of an example each, explain the role of transgenic animals in the following:
    • [(i)] Vaccine safety
    • [(ii)] Biological products
(a) “The process of evolution of different species in a given geographical area starts from a point and literally radiates to other geographical areas.” Explain it with an example.
(b) Cite an example where more than one adaptive radiation has occurred in an isolated geographical area. Name the type of evolution your example depicts.

Construct and label a transcription unit from which the RNA segment given below has been transcribed. Write the complete name of the enzyme that transcribed this RNA.

Gene therapy can be used to treat an ADA deficient patient. Explain.
Is it a permanent cure? How can ADA be cured permanently?
Student to attempt either option (A) or (B): (A) Ravi lives in a village where he suggested to the local farmers to introduce a fungus as biofertilizer into their crop fields. State the benefits provided by the fungus to the crop.
OR
(B)
  • [(i)] How do secondary lymphoid organs provide immunity?
  • [(ii)] Highlight the role of spleen as an organ that provides immunity.
Student to attempt either option (A) or (B): (A) How is DNA isolated in purified form from a bacterial cell?
OR
(B) Explain how human functional insulin was produced by using recombinant DNA (rDNA) technology.
Assertion (A): Swiss cheese is characterized by large holes due to CO2 production.
Reason (R): It is ripened by growing a specific fungi.
Assertion (A): A piece of DNA inserted into an alien organism generally does not replicate, if not inserted into a chromosome.
Reason (R): \textit{Chromosomes have specific sequences called ‘ori’ region, where DNA replication is initiated.
Assertion (A): Biotechnology produces transgenic microorganisms that function as microfactories for proteins.
Reason (R): Transgenic microorganisms can be developed to produce proteins of human use, like insulin.
Assertion (A): A male individual always inherits haemophilia from his mother.
Reason (R): The gene for haemophilia lies on X-chromosome.