Recombination DNA technology (Genetic Engineering) allows genes to be transferred 1. across different species of plants 2. from animals to plants 3. from microorganisms to higher organisms Select the correct answer using the codes given below.
Contents13
- A1 only
- B2 and 3 only
- C1 and 3 only
- D1, 2 and 3
Show answer
Answer: (D) 1, 2 and 3
Recombinant DNA technology (genetic engineering) is the general name for taking a piece of one organism's DNA and combining it with another organism's DNA.
The whole power of this technology lies in its ability to cross species barriers that are impossible in natural breeding.
All three statements are correct with real examples:
(1) Across different species of plants — e.g., the gene 'Chitinase' has been transferred from one plant species (Rice) to other plants to confer fungal resistance.
(2) From animals to plants — e.g., the gene '2'-5' oligoadenylate synthetase' from Rat has been transferred to plants to confer virus resistance.
(3) From microorganisms to higher organisms — e.g., the Bt gene from the bacterium Bacillus thuringiensis has been inserted into cotton (Bt Cotton) to make it pest-resistant.
Also, human proteins like 'Somatostatin' have been synthesized from genes inserted into bacteria.
So all three are correct.
Recombinant DNA technology can transfer genes across any species barrier - plants to plants, animals to plants, and microorganisms to higher organisms like the Bt gene from bacteria inserted into cotton.
The key concept is that genetic engineering breaks natural breeding limitations, allowing transfer between completely unrelated organisms that could never crossbreed naturally.
Recombinant DNA Technology
Science And Technology Recombination DNA technology Genetic Engineering genes to be transferred
Recombinant DNA Technology: Cross-Species Gene Transfer & Applications
Recombinant DNA technology allows genes to be transferred across all species barriers — plants to plants, animals to plants, microorganisms to higher organisms
Bt Cotton uses bacterial genes (Bacillus thuringiensis) for pest resistance — classic example of microorganism to plant transfer
Technology breaks natural breeding limitations by combining DNA from any two organisms
Chitinase gene from rice transferred to other plants for fungal resistance
Core Concept
Recombinant DNA technology (genetic engineering) combines DNA from different organisms to create new genetic combinations impossible in nature. Unlike traditional breeding which works only within species, this technology crosses all species barriers — the key breakthrough that makes modern biotechnology possible.
Cross-Species Gene Transfer Examples
Transfer Type | Source → Target | Gene/Protein | Purpose | Example |
|---|---|---|---|---|
Plant to Plant | Rice → Other plants | Chitinase | Fungal resistance | Disease-resistant crops |
Animal to Plant | Rat → Plants | 2'-5' oligoadenylate synthetase | Virus resistance | Antiviral crops |
Microorganism to Plant | Bacillus thuringiensis → Cotton | Bt gene | Pest resistance | Bt Cotton |
Higher organism to Microorganism | Human → Bacteria | Somatostatin | Protein production | Medical insulin production |
Key Advantages
Precision: Target specific genes rather than entire genomes
Speed: Skip decades of traditional breeding programs
Novel traits: Introduce characteristics impossible through natural breeding
Scalability: Mass produce valuable proteins using bacterial factories
Question Analysis
This question tests whether students understand that genetic engineering has no species limitations. All three statements are correct because the technology's fundamental power lies in crossing natural barriers that restrict traditional breeding.
Trap: Thinking gene transfer works only within plant families — actually works across all kingdoms of life
Trap: Assuming animal genes cannot function in plants — they can with proper regulatory sequences
Trap: Believing microorganism genes are too simple for higher organisms — Bt Cotton proves otherwise
Confusion: Recombinant DNA vs Hybrid breeding — only recombinant DNA crosses species barriers
Bt Cotton Technology
Science And Technology Bt gene Bacillus thuringiensis
Bt Cotton: Bacterial Genes for Pest Resistance
Bt Cotton contains genes from Bacillus thuringiensis bacteria that produce insecticidal proteins
Target pest: American bollworm — major cotton pest in India
India is the largest Bt Cotton producer globally
Cry proteins from Bt bacteria kill specific insects when ingested
Mechanism
Bacillus thuringiensis naturally produces Cry proteins that are toxic to specific insects. When the Bt gene is inserted into cotton plants, they produce these proteins continuously. Insects eating the plant ingest the toxin and die, providing built-in pest protection.
How Bt Cotton Works
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**Gene Insertion**
**Bt gene** from *Bacillus thuringiensis* inserted into cotton DNA`"]
s2["`**Protein Production**
Cotton plant produces **Cry proteins** in all tissues`"]
s3["`**Pest Attack**
**American bollworm** or other target pests eat cotton leaves/bolls`"]
s4["`**Toxin Activation**
**Cry proteins** activate in insect's alkaline gut environment`"]
s5["`**Pest Death**
Toxin destroys gut lining, killing the pest within days`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5India Context
2002: First Bt Cotton variety approved in India
Maharashtra, Gujarat, Andhra Pradesh: Leading Bt Cotton producing states
Reduced pesticide use: Farmers report 30-40% less chemical spraying
Yield increase: 30-60% higher yields compared to conventional cotton
Trap: Thinking Bt Cotton is resistant to all pests — only effective against specific lepidopteran insects
Trap: Confusing Bt with Bt brinjal — Cotton is approved, brinjal is not yet approved in India
Confusion: Cry proteins vs Bt bacteria — plants produce the proteins, not live bacteria
Genetically Modified Crops in India
Science And Technology
GM Crops in India: Current Status & Regulatory Framework
Bt Cotton is the only GM crop commercially approved for cultivation in India
GEAC (Genetic Engineering Appraisal Committee) under Ministry of Environment regulates GM crops
Bt Brinjal approved by GEAC but moratorium imposed by government in 2010
Field trials ongoing for GM mustard, rice, and other crops
Regulatory Process
GM crops in India require multi-stage approval from laboratory testing to contained field trials to large-scale trials before GEAC can grant commercial cultivation approval. The process typically takes 8-12 years and involves safety assessments for environment, food, and feed.
GM Crop Status in India
Crop | Status | Stage | Key Details |
|---|---|---|---|
Bt Cotton | Approved | Commercial cultivation | Since 2002, covers 95% of cotton area |
Bt Brinjal | Moratorium | Approved but banned | 2010 indefinite moratorium by Environment Minister |
GM Mustard (DMH-11) | Under review | Seeking commercial approval | Herbicide-tolerant variety |
Golden Rice | Field trials | Biosafety evaluation | Vitamin A enriched rice |
Bt Rice | Field trials | Contained trials | Multiple varieties under testing |
Current Challenges
Public resistance: Concerns about food safety and farmer dependency
Regulatory delays: Approval process takes over a decade
Political sensitivity: State governments opposing GM crop trials
Import dependency: India imports GM soybean oil but bans GM food crop cultivation
Trap: Thinking multiple GM crops are approved in India — only Bt Cotton is commercially allowed
Trap: Confusing GEAC approval with commercial cultivation — Bt Brinjal shows they're different
Confusion: GM import vs GM cultivation — India imports GM soy but restricts domestic GM food crops