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Unformatted text preview: Laura Irastorza BSC2011 Assignment II – Part A 1. There has been a lot of research done on how breast cancer develops and whether it is hereditary or not. After many years of research scientists discovered two genes that affect breast cancer growth. In 1994 BRCA1 and BRCA2 where identified. BRCA1 is located on chromosome 17 while BRCA2 is located on chromosome 13. They both belong to the tumor suppressing gene family. More specifically, BRCA1 and BRCA2 are known for repairing double-stranded DNA. They both interact with the RAD51 protein while repairing malfunctioning DNA. Therefore, when there are mutations with BRCA1 and BRCA2 the repair function may become disabled thus allowing many gene replication errors to slip by. This could possibly cause many cancerous growths. If these two genes are mutated they cannot suppresses tumors as they are supposed to do. Instead of restricting cell division, they allow it and tumors continue to grow undetected. These two genes are also linked to ovarian and prostate cancer. 2. Since flower color is controlled by one gene alone it would be easy to determine whether complete dominance, co-dominance, or incomplete dominance occurred. The first would be complete dominance. This means that one allele is dominant and other allele is recessive. If one walked through a garden and saw pea plants growing, for example, one would probably see about a 3 to 1 ratio of one color plant to the other. Let us just say the dominant color is purple and the recessive is white, therefore one would see a 3 to 1 ratio of purple flowers to white flowers. This is because if you had a true breeding purple (dominant) flower breed with a white (recessive) flower, the whole first generation would...
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- Fall '08