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Atypical inheritance

Two questions on a word attachment.

Why do the alleles for red/green color blindness, Duschenne muscular dystrophy and hemophilia not follow typical inheritance patterns? List and briefly explain two other exceptions to simple Mendelian inheritance

You are given two true-breeding pea plants, one for the dominant characteristic of inflated pods and the other for the related recessive characteristic of constricted pods. (See Figure 11.3 in the text.) You perform a monohybrid cross of the two plants. What would be the genotypes and phenotypes of the P generation, F1 generation and F2 generation each respectively? For genotypes use "I" to represent the dominant allele for inflated pods and "i" to represent the recessive allele for constricted pods.The allele for detached earlobes is dominant in humans while the allele for attached earlobes is recessive. If two persons with attached earlobes have children what percentage are likely to have attached earlobes? detached earlobes? Would the answer necessarily be the same if the two parents both had detached earlobes? Why or why not?

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1. Why do the alleles for red/green color blindness, Duschenne muscular dystrophy and hemophilia not follow typical inheritance patterns? List and briefly explain two other exceptions to simple Mendelian inheritance

Red-green color blindness and DMD are examples of X-linked diseases. Since they are carried on the X chromosome males are more likely than females to exhibit the disease. Instead of needed two recessive alleles as in the case of Mendelian traits, males with one diseases X chromosome and a Y chromosome will exhibit the disease. Other exceptions to Mendelian inheritance are Huntington (whose severity and age of onset depends on the size of a triplet expansion) and Leber's ...

Solution Summary

Detailed examination with web references of atypical inheritance patterns of red/green color blindness, Duschenne muscular dystrophy and hemophilia. Included are mono- and di-hybrid cross problems with solutions.

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