Molecular Basis of Inheritance — Part 2: Replication, transcription and translation: visual lesson, CBSE Class 12 Biology

Lesson

From DNA to protein

Part 2 — how DNA is copied, how its message is transcribed into RNA, and how RNA is translated into protein.

In this lesson you will

Explain semi-conservative replication and the Meselson–Stahl experiment
Describe the replication fork, leading and lagging strands
Describe transcription in bacteria and eukaryotes, including RNA processing
State the features of the genetic code and explain translation

Concept

Semi-conservative replication

Watson and Crick proposed that the two strands separate and each acts as a template for a new complementary strand. Each daughter molecule then has one parental and one new strand: semi-conservative replication.

Diagram

The Meselson–Stahl experiment (1958)

E. coli was grown for many generations in ¹⁵NH₄Cl (heavy nitrogen), then transferred to normal ¹⁴N medium. DNA was separated by density in a caesium chloride (CsCl) gradient.

Cookies