Gene Expression — Part 2: Regulation, the Human Genome Project and DNA fingerprinting: visual lesson, ISC Class 12 Biology

Lesson

Regulation, genomes and fingerprints

Part 2 — how genes are switched on and off, how the human genome was read, and how DNA identifies people.

In this lesson you will

Explain how lactose switches on the lac operon
State the goals, methods, salient features and applications of the Human Genome Project
Outline DNA fingerprinting and its applications and ethical issues

Concept

Levels of gene regulation

In eukaryotes expression can be regulated at several levels; in bacteria, control of transcription initiation is the main one.

Table of levels of regulation of gene expression
Level	Example
Transcription	Formation of the primary transcript
Processing	Splicing of hnRNA
Transport	mRNA moving from nucleus to cytoplasm
Translation	Rate of protein synthesis

Diagram

The lac operon

Proposed by Jacob and Monod, the lac operon has a regulatory gene i (makes the repressor), the promoter p, the operator o, and structural genes z (β-galactosidase), y (permease) and a (transacetylase). Lactose (allolactose) is the inducer.

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