Biotechnology and Its Applications

Notes

Introduction

What is Biotechnology?

Biotechnology is the application of living organisms, cells, enzymes, or biological systems to produce useful products and improve the quality of human life.

Applications of Biotechnology

Agriculture

Medicine

Industry

Environment

Forensic Science

Gene Therapy

This chapter mainly focuses on:

Genetically Modified (GM) Crops

Medical Biotechnology

Gene Therapy

Molecular Diagnosis

Transgenic Animals

Ethical Issues (Biopatents & Biopiracy)

1. Biotechnology in Agriculture

Genetically Modified Organisms (GMOs)

Definition

Organisms whose DNA has been altered using genetic engineering to introduce desirable traits.

Objectives of GM Crops

Insect resistance

Herbicide resistance

Disease resistance

Higher yield

Improved nutritional value

Stress tolerance (drought/salinity)

Reduced post-harvest losses

Bt Crops (Bt Cotton)

What is Bt?

Bt stands for Bacillus thuringiensis, a soil bacterium.

It produces Cry proteins (Cry toxins) that kill insect larvae.

Cry Genes

Gene Target Insect

Cry IAc Cotton bollworm

Cry IIAb Cotton bollworm

Cry IAb Corn borer

Mechanism of Action

Bt bacterium produces inactive Cry protein.

Insect larva eats Bt crop.

Alkaline pH of insect gut activates Cry protein.

Cry toxin creates pores in gut cells.

Larva dies due to starvation and infection.

Advantages of Bt Crops

Reduces pesticide use.

Higher crop yield.

Environment-friendly.

Cost-effective.

Pest-Resistant Plants (RNA Interference - RNAi)

Definition

RNA interference (RNAi) is a biological process in which double-stranded RNA (dsRNA) suppresses the expression of a specific gene.

Example

Nematode Meloidogyne incognita infects tobacco roots.

Scientists introduced dsRNA into tobacco plants.

When the nematode feeds on the plant:

dsRNA enters the nematode.

Target gene expression is blocked.

Nematode dies.

Importance

Pest control without harmful chemicals.

Eco-friendly.

2. Biotechnology in Medicine

Biotechnology has revolutionized healthcare through:

Recombinant medicines

Vaccines

Gene therapy

Molecular diagnosis

Recombinant Human Insulin (Humulin)

Diabetes Mellitus

A disease caused by deficiency of insulin.

Earlier insulin was obtained from pigs and cattle.

Problems:

Allergic reactions

Limited supply

Recombinant Insulin

Developed using E. coli bacteria.

Scientists

Eli Lilly Company

Two DNA chains (A & B) were produced separately.

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