Science (English Medium) Class 12 - CBSE Important Questions

State the aim and describe Messelson and Stahl’s experiment.

How are the following formed and involved in DNA packaging in a nucleus of a cell?

Differentiate between Euchromatin and Heterochromatin.

List the criteria a molecule that can act as genetic material must fulfill. Which one of the criteria are best fulfilled by DNA or by RNA thus making one of them a better genetic material than the other? Explain.

Give an example of a codon having a dual function.

State the difference between the structural genes in a Transcription Unit of Prokaryotes and Eukaryotes.

List two essential roles of ribosomes during translation.

How is Prokaryotic Transcription process different in eukaryotes?

Explain the processing the hnRNA needs to undergo before becoming functional mRNA in eukaryotes.

Explain the role of initiator tRNA in the initiation of protein synthesis.

Write the percentage of the total human genome that codes for proteins and the percentage of discovered genes whose functions are known as observed during HGP.

Expand the ‘SNPs’ identified by scientists in HGP.

How does a degenerate code differ from an unambiguous one?

Write the function of RNA polymerase II.

Explain the process of transcription in Eukaryotes.

Explain the role of histones in forming a nucleosome.

Write any six salient features of the human genome as drawn from the human genome project.

Answer the following question.
Write the basis on which Alfred Sturtevant explained gene mapping.

Differentiate between the genetic codes given below:
Unambiguous and Universal

Differentiate between the genetic codes given below:
Degenerate and Initiator