Genetic Modification

Genetic modification works because the genetic code is UNIVERSAL — every organism uses the same A/T/C/G alphabet. So a gene from a human can be read and used by a bacterium.

The 4 basic steps:

1. IDENTIFY the gene you want (e.g. human insulin gene).
2. CUT IT OUT using RESTRICTION ENZYMES — molecular scissors that cut DNA at specific sequences.
3. INSERT the gene into a VECTOR. The vector is usually a PLASMID (a small ring of bacterial DNA). The same restriction enzyme is used so the ends match.
4. TRANSFER the plasmid into the target organism (e.g. E. coli). The bacterium now reads the human gene and makes insulin.
5. GROW the modified organism in large quantities.

The trick that makes this work is the RESTRICTION ENZYME. It always cuts at the same sequence (e.g. GAATTC), leaving 'sticky ends' that can re-join with any other DNA cut by the same enzyme. So the insulin gene and the plasmid can be glued together.

Medical:

• Insulin — already covered. Saves the lives of millions of diabetics.
• Vaccines — some flu and hepatitis-B vaccines use GM yeast to make a viral protein.
• Gene therapy (still experimental): inserting a working gene into a patient with a genetic disorder (e.g. cystic fibrosis, sickle-cell).

Agricultural:

• Bt-cotton / Bt-corn: insert a bacterial gene (from Bacillus thuringiensis) that codes for a protein toxic to caterpillars. Crop is then naturally pest-resistant — less pesticide needed. Widely grown in India, China, US.
• Golden Rice: rice modified to produce beta-carotene (vitamin A precursor). Designed to prevent blindness from vitamin-A deficiency in poorer countries.
• Herbicide-resistant crops (e.g. 'Roundup-Ready' soybeans): allow farmers to spray weedkiller without harming the crop. Boosts yields but raises herbicide use.

Environmental:

• GM bacteria that BREAK DOWN oil spills, plastics or heavy metals.
• 'Bioremediation' projects use these to clean polluted soils.

Concerns that are taken seriously:

• Cross-pollination. GM plants can pollinate wild relatives, potentially spreading the modification beyond farmers' fields.
• Loss of biodiversity. When everyone uses the same engineered crop variety, native varieties disappear.
• Antibiotic-resistance markers. Some early GM techniques used resistance genes to track insertion; these could spread to disease bacteria.
• Allergens. Adding a gene from a peanut into wheat could give people unexpected allergic reactions.
• Corporate control / patents. Big seed companies own patents on GM seeds; farmers can't replant seeds from their own crop, and have to buy new ones each year.
• Animal welfare. Some GM animals (e.g. AquAdvantage salmon) may suffer health problems.

Counter-arguments:

• The same risks (cross-pollination, allergens) exist in conventional breeding.
• Properly regulated, GM has saved millions of lives (insulin) and reduced pesticide use (Bt-cotton).
• The science is well-understood, with 30+ years of safety data.

The MYP grade-7 answer doesn't take a one-sided 'GM is wrong' or 'GM is fine' position. It IDENTIFIES specific risks and benefits, weighs them, and discusses HOW REGULATION can manage the risks.