Gene and Genetic Engineering

If you think why dogs give birth to dogs, cats give birth to cats, or an apple seed grows into an apple tree, you are thinking basic questions of Genetics. That phenomenon is called heredity. Why are we humans? The answer is simple: we are humans because our parents are humans. Our parents passed the information of humans to us and based on that kind of information we developed into humans. The information our parents passed to us is called Genetic Information. A unit of the genetic information is called a gene.

Genes exist in the sequence of DNA, a large molecule contained in the cells. DNA is composed of four bases, A, T, G, C. Different genes have different lengths and sequences.

Genes are softwares, or programs of an organism. They determine how an organism looks, how it takes its food, how it fights infection, and sometimes how it behaves. Change of a gene can mean death, illness or characteristic change to an organism.

The technique involving direct manipulation of genes is called genetic engineering.

One example of application of genetic engineering is Bt cotton. Bt represents Bacterial Toxin, a kind of protein encoded by Bacteria Bt gene. Bt is toxic to some insects. Bt gene is a bacteria gene. Cotton or other plants don’t naturally have the gene. Scientists have isolated the Bt gene from bacteria and transferred it into some cotton plants. The cotton plants that obtain the Bt gene are called genetically modified cotton or Bt cotton. Bt cotton can produce bacterial toxin, which can kill pests that eat the cotton. Nowadays, Bt cotton has widely planted in USA, China and India. Application of Bt cotton can increase yield, save farm labor and avoid pesticide contamination.

Another example of application of genetic engineering is Gene Therapy, a technique of directly using genes to treat or prevent diseases. Recently, scientists in University of Washington injected genes that produce color-detecting proteins into two color-blind monkeys and cured the color-blind monkeys. The two monkeys have been able to see red and green for the first time.

Genetic engineering has already emerged as a powerful technique in agriculture and medicine. It is expected that genetic engineering will provide revolutionary technology to solve energy, environmental, and global warming problems in the future.

Someone says that the 20th century is the century of physics and 21st century is the century of biology. I believe it.

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The above is one of 5-7 minute speeches that I delivered in my Toastmaster Club.