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Basic Structure of a Cell

Basic Structure of a Cell :



millions of these bases form sections of DNA that are called genes. Genes determine the characteristics that living things have. Human cells contain about one hundred thousand genes in all. They are made up of approximately six billion A’s, C’s, T’s and G’s, all in a specific order. When (:0115 reproduce, occasionally an error occurs in the reproduction of their DNA. An A, for example, is copie(l instead of a C, or a G instead of a T. These errors are mutations—permanent changes in the DNA. A mutation causes the production of a prot ein that is different from the original one. If the mut ated genes are present in the organism’s sex cells, they will be transmitted to the offspring. Some mutations can be fatal, but others produce a newer, stronger,better-equipped organism than the original “correct” one. In the process of genetic engineering, scientists add or delete whole sections of DNA in coils in order to prod
uce specific, intended changes in living organisms.

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