Genetics Assignment Example | Topics and Well Written Essays - 1250 words

Genetics - Assignment Example Accordingly, the accumulation of mutant mtDNA in the reproductive tissues appears to underlie/impair fetal viability, thus, increasing chances of having recurrent miscarriages. 8 In the following pedigrees, the disorders or traits presented follow simple patterns of Mendelian inheritance. For each trait, determine the most probable mode of inheritance, stating whether the trait is due to an autosomal or X-linked gene, and a dominant or recessive allele. In each case, indicate and explain the evidence for each pattern, giving at least one statement and example from the pedigree to defend each part of your analysis. Then, providing a legend for your symbols, assign genotypes to the specified individuals. (15 marks) 9 Achondroplasia is an autosomal dominant disorder associated with a gene on chromosome 4. Sickle cell anaemia is due to a gene on chromosome 11. A man and a woman with achondroplasia, who each had a normal parent, are carriers for sickle cell anaemia. Every individual has two copies of each of the genes in their system, one from each parent. The color of the human eye color is determined by at least three hereditable genes. However, only two are well understood. A gene often has two alleles: a dominant one that confers eye color (B for blue eye color) and a recessive one which gives rise to the brown eye color. A brown eyed dad and a green eyed mom may be carriers of the recessive gene of eye color, and thus be able to pass down brown eye genes to their children. As alluded to in the diagram above, both parents are carriers of the brown eyes genes. There is, thus, a slim chance that brown eyed child [bb/gg] being born in the family. Both lead to monoallelic expression [without altering the genetic sequence]; that is genomic imprinting and X-inactivation share certain physical properties such as DNA hypermethylation, altered replication timing