Gene regulation governing lactose operon of E. coli that involves the lac I gene product is:

Which of the following are the post-transcriptional events in an eukaryotic cell? A. Transport of pre-mRNA to cytoplasm prior to splicing. B. Removal of introns and joining of exons. C. Addition of methyl group at 5' end of hnRNA. D. Addition of adenine residues at 3 ' end of hnRNA. E. Base pairing of two complementary RNAs. Choose the correct answer from the options given below :

Histones are enriched with -

Who proposed that the genetic code for amino acids should be made up of three nucleotides?

Match List I with List II: $\begin{array}{|l|l|l|l|}\hline & \text{List - I} & & \text{List - II} \\\hline \text{A}. & \text{Alfred Hershey and Martha Chase} & \text{(i)} & \text{Streptococcus pneumoniae} \\\hline \text{B.} & \text{Euchromatin} & \text{(ii)} & \text{Densely packed and dark-stained} \\\hline \text{C.} & \text{Frederick Griffith} & \text{(iii)} & \text{Loosely packed and light-stained} \\\hline \text{D.} & \text{Heterochromatin} & \text{(iv)} & \text{DNA as genetic material confirmation} \\\hline\end{array}$ Choose the correct answer from the options given below:

Given below are two statements : Statement I : In the RNA world, RNA is considered the first genetic material evolved to carry out essential life processes. RNA acts as a genetic material and also as a catalyst for some important biochemical reactions in living systems. Being reactive, RNA is unstable. Statement II: DNA evolved from RNA and is a more stable genetic material. Its double helical strands being complementary, resist changes by evolving repairing mechanism. In the light of the above statements, choose the most appropriate answer from the options given below :