$A$ : $5S$ $rRNA$ and surrounding protein complex provides binding site of $tRNA$.
$R$ : $tRNA$ is soluble $RNA$ with unusual bases.

$DNA$ generally acts as a template for the synthesis of:

Given below are two statements.
Statement $I$: Heterocatalytic function of $DNA$ includes transcription and translation.
Statement $II$: $A$ unique feature of $DNA$ molecule which helps in its semiconservative duplication is the complementary nature of two strands.
In the light of the above statements,choose the correct answer from the options given below.

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?

In which of the following is the flow of genetic information in the reverse direction?

How many of the given statements $(i-iv)$ is/are correct?
$i.$ In transcription,adenosine pairs with uracil.
$ii.$ Regulation of lac operon by repressor is referred to as positive regulation.
$iii.$ The human genome has approximately $50,000$ genes.
$iv.$ Haemophilia is a sex-linked recessive disease.