Genetic mapping of bacteriophage $\phi X174$ has been done by

Match the following and select the correct option:
Column $A$ | Column $B$
$(i)$ Oncogenes | $(1)$ Causes $AIDS$
(ii) Single circular $DNA$ | $(2)$ $Lac$-Operon concept
(iii) Splicing | $(3)$ Component of bacterial chromosome
(iv) Jacob and Monod | $(4)$ Processing of $mRNA$ molecules
| $(5)$ When activated cause cancer
Select the correct sequence for $(i), (ii), (iii), (iv)$ respectively.

Match the process in Column-$I$ with the enzyme involved in Column-$II$.

Column-$I$	Column-$II$
$(A)$ $DNA$ replication	$(p)$ $RNA$ polymerase
$(B)$ Translation	$(q)$ $DNA$ polymerase
$(C)$ Transcription	$(r)$ Reverse transcriptase
$(D)$ Reverse transcription	$(s)$ Aminoacyl synthetase

Select the code for the correct answer from the options given below.

Read the following four statements ($1$ to $4$):
$1$. In transcription,uracil pairs with adenosine.
$2$. Regulation of $lac$ operon by a repressor is referred to as positive regulation.
$3$. The human genome contains approximately $50,000$ genes.
$4$. Haemophilia is a sex-linked recessive disease.
How many of the above statements are correct?

Segment of $DNA$ which is responsible for inheritance and expression of a particular character is known as

The central dogma of molecular biology is shown below. Identify the processes $P, Q,$ and $R$.