Question

A. Look at the above sequence and mention the events A, B, and C.
B. What does Central Dogma state in molecular biology? How does it differ in some virus?

Answer 1

Hint: DNA is a double helical structure that stores genetic information. Although DNA and RNA both function as genetic material, DNA is more stable (both chemically and structurally) and therefore, is a better genetic material.

Complete answer:
While DNA stores the genetic information, RNA helps in its transfer and expression. RNA is evolved much before DNA, and DNA is considered to be derived from RNA. The hydrogen bonding between the opposite strands makes the DNA much stable by making one strand complementary to the other.
(a) In the given diagram, A represents the process of Replication, B represents the process of Transcription, and C represents the process of Translation.
(b) After the structure of DNA was described, Francis Crick proposed the Central Dogma in molecular biology. It states that the genetic information can move from DNA to RNA, and RNA to Protein. DNA can replicate in a semi-conservation manner. This process is guided by the hydrogen bonding present in the complementary strands. The process of the formation of RNA from DNA is known as transcription. One of the two strands of DNA acts as the template strand for transcription to occur. The template strand directs the synthesis of the complementary strand for RNA. The process of the formation of protein from RNA is known as translation.
In some viruses, such as Retrovirus, the information can be flown from RNA to DNA in a reverse direction, instead of from DNA to RNA. This process is known as reverse transcription.

Note: Translation in prokaryotes is simple and direct as the mRNA transcribed is functional, while translation in eukaryotes is a complex process. The coding regions are separated from the non-coding regions before translation.