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  3. The Discovery of Genes Perhaps you may have wondered why you look like your father or mother, while your sister looks like an

The Discovery of Genes Perhaps you may have wondered why you look like your father or mother, while your sister looks like an

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问题                                    The Discovery of Genes
   Perhaps you may have wondered why you look like your father or mother, while your sister looks like an aunt or even one of your grandparents. The way you look, talk and move and how tall you will grow depend mostly upon the very small particles called genes, which are found in the cells of your body. You get these genes from your parents. Each time they reproduce (生育) they pass along a set of genes. But each new set may be a little different from the previous sets. So when parents have a number of children, they will find that each child looks somewhat like themselves but with individual features too.
   In the past nobody really understood why members of the same family resembled each other. All through the eighteenth and nineteenth centuries many scientists tried to find out how the features of living things were passed on to the next generation. Then in the 1860s one man succeeded in finding out the answer. He was Gregor Mendal, an Austrian who was very interested in growing plants.
   He experimented with pea (豌豆) plants. He found that there was something in the parent plant that gave the offspring (后代) certain features, such as tallness or shortness. This "something" is now called genes. He also discovered that of all the features of a plant which were passed on to another generation, some were stronger than others. In such a case the stronger features would be dominant in the new plants. He proved this by crossing a purple-flowered plant with a white-flowered plant--the first new generation all had purple flowers. But when seeds from the new purple-flowered plants grew up, one plant of this generation was white. So although the white features did not show in the plants of the first generation, it had been there all the time.
   Mendal published his findings in 1866, but it was only in 1900 that the importance of his work was recognized. Scientists realized that his theories on heredity (遗传) could also be applied to all forms of life, including humans.
选项 A、completely on his own genes.
B、largely on his parents’ genes.
C、mostly on his brothers’ genes.
D、mainly on his sisters’ genes.
答案C
解析
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