Crops developed by integrating a foreign gene into their genome to obtain desirable traits such as high yield, disease resistance, and tolerance to stresses like alkalinity, cold, drought, and weeds are called genetically modified crops.
Definitions [8]
Define.
Biotechnology
The technique of bringing about improvements in living organisms by genetic modifications and hybridization, for the welfare of human beings is known as ‘Biotechnology’.
Definition: Biotechnology
The European Federation of Biotechnology (EFB) defined biotechnology as ‘the integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services.’
Define genomic library.
A genomic library is a collection of clones that represent an organism's whole genome.
Definition: Hybrid Seeds
Seeds produced by recombination of genes from two different crop varieties to obtain improved characteristics, especially in fruits, are called hybrid seeds.
Define the term:
Bioethics
Bioethics is the branch of ethics that deals with moral principles and issues arising from advances in biology, medicine, and life sciences.
Definition: Biopiracy
Biopiracy is defined as ‘theft of various natural products and then selling them by getting patent without giving any benefits or compensation back to the host country’.
or
It is an unauthorised misappropriation of any biological resource and indigenous knowledge.
Definition: Genetically Modified Crops (GMOs)
Definition: Polymerase Chain Reaction (PCR)
The in-vitro technique used to amplify a specific segment of DNA, producing millions of copies from a small amount of DNA in a short time using repeated thermal cycles, is called polymerase chain reaction (PCR).
Key Points
Key Points: Biotechnology
- Biotechnology involves the use of biological systems, cells, and biomolecules along with genetic and non-genetic techniques for human welfare.
- It integrates sciences such as cytology, biochemistry, molecular biology, and genetic engineering and has major applications in agriculture and pharmacy.
- Biotechnology enables production of antibiotics, vaccines, hormones (insulin), antibodies, and development of high-yield crop varieties through tissue culture and gene manipulation.
- Major benefits include increased crop yield, development of disease- and stress-resistant varieties, and reduced expenditure on disease control.
- In India, biotechnology is promoted by the Department of Biotechnology (DBT) established in 1986, under which several national research institutes function.
Key Points: Genetically Modified Organisms (GMOs)
| Crop / Variety | Gene Source | Introduced Character | Target / Function | Advantage |
|---|---|---|---|---|
| Bt Cotton | Bacillus thuringiensis | Insecticidal toxin production | Bollworm control | Prevents crop damage |
| Bt Brinjal | Bacillus thuringiensis | Insect resistance | Pest destruction | Reduces pesticide use |
| Golden Rice | Beta carotene synthesizing gene | Vitamin A production | Nutritional enhancement | Prevents vitamin A deficiency |
| Herbicide tolerant crops | Genetically modified plant genes | Herbicide resistance | Weed control | Selective destruction of weeds without harming crop |
Key Points: Mechanism of PCR
| Step | Temperature | Process | Result |
|---|---|---|---|
| Denaturation | 90–98 °C | Double-stranded DNA separates into single strands | Template strands formed |
| Annealing | 40–60 °C | Primers bind to complementary sequences on DNA | Primer-template complex formed |
| Extension (Elongation) | 70–75 °C | Taq DNA polymerase adds nucleotides to primers | New DNA strands synthesized |
| Completion of One Cycle | — | One complete set of three steps | DNA quantity doubles |
| Repeated Cycles | — | Steps repeated 20–30 times | Millions of DNA copies formed |
Key Points: Methodology for rDNA Technology
| Stage | Description | Key Tools / Examples |
|---|---|---|
| Isolation of DNA (Gene) | Desired gene is isolated, purified, and cleaved using restriction enzymes | Restriction endonucleases |
| Insertion into Vector | Foreign (passenger) DNA is inserted into plasmid/phage vector to form rDNA | DNA ligase, pBR322, λ phage |
| Transfer into Host | Recombinant DNA is introduced into competent host cell | Transformation, Ca²⁺, E. coli, Agrobacterium |
| Selection of Transformants | Recombinant cells are identified using marker genes | Antibiotic resistance (Ampᴿ, Tetᴿ) |
| Multiplication | Selected transformed cells are cultured and multiplied | Culture media |
| Expression of Gene | Desired product is synthesized and purified | Bioreactors, downstream processing |
Important Questions [14]
- Give an Example of the Source of Thermostable Enzyme Dna Polymerase.
- What are plasmids?
- The biological scissor is ______.
- The recognition sequence of restriction enzymes is generally ______ nucleotide long.
- Annealing step of PCR operates at ______ C.
- Name the plant disease caused by Agrobacterium tumefaciens.
- What is polymerase chain reaction (PCR)?
- Describe three steps involved in mechanism of PCR.
- Give the applications of PCR technique.
- CDNA means ______.
- In the process of rDNA technology, if two separate restriction enzymes are used to cut vector and donor DNA then which problem will arise in the formation of rDNA or chimeric DNA? Explain.
- What are the effects of biotechnology with relation to human health?
- What is ‘biopatent’? Give any two examples.
- Explain any three examples of biopiracy.
Concepts [12]
- Biotechnology
- Principles of Biotechnology
- Methodology for rDNA Technology
- Crop Biotechnology > Hybrid Seeds
- Bioethics
- Effects of Biotechnology on the Environment
- Biopiracy
- Transgenic Plants
- Effects of Biotechnology on Human Health
- Tools and techniques for gene cloning/ rDNA technology
- Crop Biotechnology > Genetically Modified Organisms (GMOs)
- Overview of Biotechnology
