Base substitution caused by base analogs is known as:

Statement-$I$: The split gene arrangements represent probably an ancient feature of the genome.
Statement-$II$: Introns or intervening sequences do not appear in mature or processed $\text{RNA}$.

Read the following statements $:-$
$(i)$ Eukaryotic $\text{mRNA}$ is polycistronic whereas prokaryotic $\text{mRNA}$ is monocistronic.
$(ii)$ Prokaryotic $\text{mRNA}$ is cap-less and tail-less whereas eukaryotic $\text{mRNA}$ is with cap and tail.
$(iii)$ The precursor of prokaryotic $\text{mRNA}$ is $\text{hnRNA}$.
$(iv)$ In replication,only one of the strands acts as a template.
$(v)$ In eukaryotes,transcription occurs in the nucleus and translation in the cytoplasm.
Which of the above statements are correct?

Assertion : Histones are basic proteins of major importance in packaging of eukaryotic $DNA$. $DNA$ and histones comprise chromatin forming the bulk of eukaryotic chromosome.
Reason : Histones are of five major types $H_1, H_2A, H_2B, H_3$ and $H_4$.

Which one of the following pairs is not correctly matched?

The $1$ gene $1$ enzyme relationship was first established in .......... .