Describe Transcription.

(N/A) Transcription is the process of copying genetic information from one strand of the $DNA$ into $RNA$.
The process of transcription is governed by the principle of complementarity,except that adenosine now forms a base pair with uracil instead of thymine.
Unlike replication,where the total $DNA$ of an organism is duplicated,in transcription only a segment of $DNA$ and only one of the two strands is copied into $RNA$.
Reasons why both strands are not copied at the same time during transcription:
$(i)$ If both strands were copied,they would code for $RNA$ molecules with different sequences (because complementary does not mean identical). Consequently,two proteins with different amino acid sequences would be produced,making the genetic information transfer machinery much more complicated.
$(ii)$ The two $RNA$ molecules produced simultaneously would be complementary to each other and would bind together to form a double-stranded $RNA$. This would prevent the $RNA$ from being translated into protein.