Molecular Basis of Inheritance — Part 3: Gene regulation, the Human Genome Project and DNA fingerprinting: visual lesson, CBSE Class 12 Biology

Lesson

Regulation, genomes and fingerprints

Part 3 — how cells switch genes on and off, what we learned by reading the whole human genome, and how DNA can identify a person.

In this lesson you will

Explain how the lac operon is switched off and on
State the goals, methods and main findings of the Human Genome Project
Explain the principle, steps and uses of DNA fingerprinting

Concept

Levels of gene regulation

Gene expression can be regulated at several levels in eukaryotes; in prokaryotes, control is mainly at the initiation of transcription.

Table of four levels of regulation of gene expression
Level	Example of control
Transcription	Whether the primary transcript is made
Processing	Splicing of the transcript
Transport	Movement of mRNA from nucleus to cytoplasm
Translation	Whether and how fast the mRNA is translated

Diagram

The lac operon

An operon is a set of genes controlled together. The lac operon (Jacob and Monod) has a regulatory gene i, a promoter, an operator and three structural genes: z (β-galactosidase), y (permease) and a (transacetylase).

Cookies