Edexcel iGCSE Biology-6.15-6.16 GM Plants & Food Production and Transgenic- Study Notes- New Syllabus
Edexcel iGCSE Biology-6.15-6.16 GM Plants & Food Production and Transgenic- Study Notes- New syllabus
Edexcel iGCSE Biology-6.15-6.16 GM Plants & Food Production and Transgenic- Study Notes -Edexcel iGCSE Biology – per latest Syllabus.
Key Concepts:
6.15 understand how genetically modified plants can be used to improve food production
6.16 understand that the term transgenic means the transfer of genetic material from one species to a different species
How GM Plants Improve Food Production
📌 Introduction
Genetically modified (GM) plants are plants whose DNA has been altered using biotechnology to introduce desirable traits.
These modifications help increase crop yield, reduce losses, and improve food quality, which is crucial to feed the growing population.
🧩 Ways GM Plants Improve Food Production
- Pest Resistance
Plants can be modified to produce toxins that kill harmful insects.
Example: Bt cotton produces a bacterial toxin that kills bollworms.
Reduces crop losses
Minimizes the use of chemical pesticides - Disease Resistance
GM plants can resist viruses, bacteria, or fungi.
Example: GM papaya resistant to Papaya Ringspot Virus.
Leads to healthy crops and higher yields - Herbicide Tolerance
Plants can tolerate certain weed-killing chemicals.
Example: GM soybeans that survive glyphosate spraying.
Allows farmers to kill weeds without harming crops - Drought and Stress Tolerance
Genes from other organisms can help plants survive dry conditions or poor soil.
Example: GM maize tolerant to drought.
Ensures stable production even in adverse conditions - Improved Nutritional Value
GM plants can be modified to produce more vitamins or minerals.
Example: Golden Rice contains beta-carotene (Vitamin A precursor).
Helps prevent malnutrition - Longer Shelf Life
GM crops can resist spoilage or ripening too quickly.
Example: GM tomatoes with slower ripening.
Reduces food wastage
⚙️ How It Works (Basic Process)
- Identify desired trait (e.g., pest resistance).
- Isolate the gene responsible for that trait.
- Insert the gene into plant cells using:
- Agrobacterium tumefaciens (natural gene transfer bacteria)
- Gene gun (physical insertion)
- Grow modified cells into full plants → GM plants ready.
🧠 Advantages
- Higher crop yield
- Reduced pesticide use → safer for environment
- Enhanced nutritional quality
- Better stress tolerance → less crop failure
⚠️ Considerations / Disadvantages
- Possible environmental effects → gene transfer to wild plants
- Ethical concerns → long-term health effects
- Cost of seeds → may be high for small farmers
📊 Summary Table
| Trait Introduced | Example | Benefit |
|---|---|---|
| Pest resistance | Bt cotton | Less insect damage, higher yield |
| Disease resistance | GM papaya | Healthier crops |
| Herbicide tolerance | GM soybean | Easier weed control |
| Drought tolerance | GM maize | Stable yield in dry regions |
| Nutritional improvement | Golden Rice | Prevents Vitamin A deficiency |
| Longer shelf life | GM tomato | Reduced wastage |
💡 Quick Recap
GM plants = DNA modified for useful traits
Main purposes → pest/disease resistance, drought tolerance, nutrition, shelf life
Methods → Agrobacterium or gene gun
Benefits → higher yield, safer, nutritious food
Drawbacks → environmental and ethical concerns
Understanding Transgenic Organisms
📌 Introduction
Transgenic organisms are organisms that have had genes transferred from one species to another.
The transferred gene may come from bacteria, plants, animals, or humans.
The goal is to give the recipient organism a useful trait that it did not naturally have.
🧩 Key Points
- Definition:
Transgenic = transfer of genetic material from one species to a different species. - How it is done:
- Identify the desired gene in donor species.
- Isolate the gene using molecular tools (restriction enzymes).
- Insert the gene into the recipient organism using:
- Plasmids (in bacteria)
- Viruses
- Gene guns / Agrobacterium (in plants)
- Grow the organism → it expresses the new trait.
- Examples:
- Bt cotton → gene from bacterium → pest resistance.
- Insulin-producing bacteria → human insulin gene → medical use.
- Glowfish → jellyfish gene → glows in the dark.
- Purpose:
- Medical: produce human proteins like insulin or clotting factors.
- Agricultural: pest/disease resistance, improved yield, nutrition.
- Scientific research: study gene function, disease models.
⚡ Quick Recap
Transgenic = gene from one species → different species
Goal: introduce useful trait
Method: isolate gene → insert into recipient → organism expresses trait
Examples: Bt cotton, GM insulin bacteria, glowfish