List of top Biology Questions

The following diagram shown restriction sites in E. coli cloning vector pBR322. Find the role of ‘X’ and ‘Y’gens :

Which cells of islets of Langerhans produce the hormone insulin?
Describe the pyramid of energy with the help of a diagram.
Give the name and type of I, IV and VII cranial nerves.
How many meiotic divisions are required for the formation of 300 seeds in angiosperm?
Double fertilization is a characteristic of
Describe the physiological effects and applications of ethylene.
Analogous structures are a result of:

Write short notes on the following: 
Chemical composition of DNA.

Answer the following questions:
(A) Stability of DNA is higher than that of RNA. How?
(B) What are the roles of the three parts of the transcription unit?
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Allergy
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Implantation
How is gene of interest amplified by using PCR?
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Autogamy
What are spermatogonia, primary spermatocytes and secondary spermatocytes?
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Phosphorus cycle
Explain the causes of biodiversity loss.
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Primary immunity
Describe the structure of microsporangium.
What are contraceptive pills? How do they function?
Explain double fertilization.
How is the name given to restriction endonucleases?
What are the factors which affect population growth?
What is cell mediated immunity?
What is cyclosporin-A and what is its use?