THE BENEFITS AND USES OF MICROBES In your opinion, what are the most important applications of biotechnology? Tick your choices and discuss them in groups. Why biotechnology? To improve the quality of life. understand and combat disease. fight hunger. eliminate pollutants and wastes from the environment. create environmentfriendly products and fuels. improve agricultural productivity and decrease the use of fertilizers and pesticides. improve the nutritional qualities and safety of foods. Other 2 MICROBIAL BIOTECHNOLOGY 1 4.4 Listen to a Biotechnology teacher introducing the main principles of Biotechnology and fill in the blanks in the passage below. Biotechnology can be broadly defined as using living (1) ............................... or their products for commercial purposes . As such, biotechnology has been practised by human society since the beginning of recorded history in such activities as baking (2) ..............................., brewing alcoholic (3) .............................., or breeding food crops or domestic (4) ................................ All living organisms are composed of cells that contain a substance called (5) ............................... (deoxyribonucleic acid) in the chromosomes. The structure of DNA molecules contains (6) ............................... that is used by cells as a recipe for the organism; that is, the (7) ............................... of any living thing essentially are determined by the information in DNA. The words for the DNA recipe, called (8) ..............................., are derived from a 4-letter alphabet (A, C, G, T). The entire recipe is called the (9) ................................ Except for the (10) ............................... and number of letters in each recipe, DNA from any organism is chemically and physically the same. One of the great scientific (11) ............................... of biotechnology is that DNA from any organism will function if it is transferred into any other organism! Combining DNA from different existing organisms (plants, animals, insects, bacteria, etc.) results in modified organisms with a combination of traits from the (12) ................................ The sharing of DNA information takes place naturally through sexual (13) ..............................., however, sexual reproduction can occur only between individuals of the same (14) ................................ What s new since 1973 is that scientists have been able to identify the specific DNA genes for many desirable (15) ............................... and transfer only those genes, usually carried on a plasmid or virus, into another organism. This (16) ...............................is called genetic engineering. Virtually any desirable trait found in (17) ............................... can, in principle, be transferred into any chosen organism. An organism modified by genetic (18) ............................... is called transgenic. 154 Module 4 ELEMENTS