Genetic Modification of Food
You have probably heard of GM foods, but do you know what GM stands for? It is short for genetic modification. “Genetic” means to do with genes and “modification” means changing.
Genes are tiny parts found inside the cells of all living things. Each species (type) of plant and animal has its own genes that make it grow and look the way it does. By changing, or modifying, genes, we can change living things. Using GM, humans can make new types of living things that have never existed before; GM foods are foods that come from crop plants that have had some of their genes changed.
A CLOSER LOOK AT GENES
All living things, including plants, animals, and humans, have genes. Living things are made up of tiny cells. Each cell has a control unit called a nucleus, and inside the nucleus are the genes. They are made of long, coiled-up strings of a chemical called DNA. The genes in a cell are like a cell’s instruction book. They tell the cell how to work, and how to make the body parts and substances that a living thing needs.
A living thing has lots of different genes that do different jobs. For example, there are genes inside your cells that decide what colour your hair is, how tall you are and what shape your nose is. Genes inside plants control things like how fast the plant grows, how strong it is and what kinds of chemicals it contains.
HOW CAN GENES BE CHANGED?
In the past 100 years, scientists have found out a lot about genes. They have understood how genes work and how different genes do different jobs. More recently, scientists learned how to take genes out of cells, and put them back into other cells. It is now possible to take a gene out of one living thing, such as a fish and put it into a cell from a different kind of living thing, such as a tomato plant. Scientists can also rearrange genes, or remove genes, to change the way a living thing works. This is what GM means.
Once the genes in a cell have been modified, the cell is grown into a new plant. The cell divides and copies itself to make more and more cells as the plant grows. This means that when the plant is fully grown, all its cells have the modified genes. Any seeds it makes will have the modified genes too.
Scientists working in laboratories have made many different types of GM plants and GM animals. Some types of GM plants have become common crops that lots of farmers use. For example, millions of people have eaten foods from GM tomato, maize and soya plants.
WHY ARE GM CROPS USEFUL?
The changes made to GM crops can make them easier to grow, bigger, longer lasting, or resistant to frost or mould. For example, one type of GM strawberry plant was made using a gene from a flounder fish that can survive in icy cold water. The gene made the strawberries survive better in frosty weather so that the crop did not go to waste. Other crops are designed to be poisonous to pest insects or to grow faster than normal.
Better crops mean more profits for farmers and food companies, and cheaper food for the public. GM crops could also help farmers in countries that suffer from droughts or poor soil, by making crops stronger and more resistant to dry weather.
GM foods have been tested for safety, and the tests show they are healthy to eat. However, some people are worried about GM crops and GM foods and think they could be dangerous. There are several reasons for this. Because GM foods are quite a new invention, it is not yet possible to say whether they could be harmful in the long run. Also, some experts say that growing GM crops can harm the environment—for example, by killing insects, or by making it harder for weeds to grow and so making it harder for some kinds of wildlife to survive. However, some GM crops can also help the environment because farmers do not need to use as much chemical pesticide spray and weedkiller.