What a GMO Is

Tissue culture and somatic hybridisation can rearrange whole cells, but genetics offers a more precise path. If farmers are to obtain the maximum yield from their fields while cutting down on fertilisers and chemicals, one promising solution is the use of genetically modified crops.

Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). The word covers a lot of ground — but in agriculture the focus is on GM plants, whose genetic makeup has been deliberately changed to give them useful new properties that ordinary varieties do not possess.

Tolerating Stress, Needing Fewer Chemicals

Genetic modification has made crops useful in several practical ways. First, it has made them more tolerant to abiotic stresses — conditions such as cold, drought, salt and heat that would normally cripple a crop.

Second, it has reduced reliance on chemical pesticides by creating pest-resistant crops. This matters both to the farmer's costs and to the environment, since fewer sprays mean less chemical runoff. Together these two benefits address the very problems that made conventional agriculture so difficult and expensive for growers in the developing world.

Protecting Yield and the Soil

GM crops also help after the plant has grown. Genetic modification has helped reduce post-harvest losses, so that more of what is grown actually reaches people rather than spoiling in storage.

It has also increased the efficiency of mineral usage by plants. This is quietly important: when plants use soil minerals more efficiently, it prevents the early exhaustion of soil fertility, keeping farmland productive for longer. In this way GM crops act not just on a single season's yield but on the long-term health of the land itself.

Better Nutrition and Beyond Food

Perhaps the most celebrated benefit is nutritional. Genetic modification has enhanced the nutritional value of food — the best-known example being golden rice, a variety of rice enriched with vitamin A, developed to combat vitamin-A deficiency in populations that depend on rice as a staple.

The reach of GM goes well beyond the dinner plate. It has been used to create tailor-made plants that supply alternative resources to industry, in the form of starches, fuels and pharmaceuticals. A crop can thus be engineered not only to feed people but to serve as a renewable factory for industrial raw materials.

Quick Recap

  • GMO = plants, bacteria, fungi and animals whose genes have been altered by manipulation.
  • GM plants are more tolerant to abiotic stresses — cold, drought, salt and heat.
  • They have reduced reliance on chemical pesticides by being pest-resistant.
  • They reduce post-harvest losses and increase efficiency of mineral usage, which prevents early exhaustion of soil fertility.
  • They enhance the nutritional value of food, e.g. golden rice (vitamin-A-enriched rice).
  • GM has also produced tailor-made plants supplying industry with starches, fuels and pharmaceuticals.

Solved Examples — Section 4

Q1. What is a Genetically Modified Organism (GMO)?

Answer: A plant, bacterium, fungus or animal whose genes have been altered by manipulation.

Q2. Name two abiotic stresses to which GM crops have been made more tolerant.

Answer: Any two of cold, drought, salt and heat.

Q3. How do GM crops help reduce the use of chemical pesticides?

Answer: By being engineered as pest-resistant crops, which lowers the need to spray chemical pesticides.

Q4. Why is increased efficiency of mineral usage by GM plants beneficial for soil?

Answer: Because efficient mineral use prevents the early exhaustion of soil fertility, keeping the land productive for longer.

Q5. Give an example of a GM crop with enhanced nutritional value.

Answer: Golden rice, a vitamin-A-enriched variety of rice.

Q6. Besides food, what industrial resources can tailor-made GM plants supply?

Answer: Starches, fuels and pharmaceuticals.