During this week (26-30 Oct) in Biology class, we started the class on Monday by conducting a mini lesson about recessive genetic disorders. Recessive genetic disorder is a disease that affect people born with recessive genes. Carriers are people who carries the gene’s disease but does not have the disease’s symptom. Example of recessive genetic disorder is cystic fibrosis where the their mucus producing gland produce excessive mucus and the mucus cannot be absorbed. Albinism is due to the inability of body to produce melanin, causing pale skin, hair and pale eyes. Tay-sachs disease is a disease that caused by the absence of enzyme responsible for breaking down fatty acid, causing them to accumulate the brain and make the neuron larger. Galactosemia is a disease where the body is unable to digest galactose, On Tuesday, we learned about dominant genetic disorder which is a disease that affect people born with dominant allele, either its homozygous or heterozygous. Example of dominant genetic disorder is Huntington’s disease which affect muscle coordination and the brain, affecting motor skills to decline. Achondroplasia is a disease that cause dwarfism, causing their body to be smaller even though they are adult and also with large head. There are no cure for any of this diseases. We also learn about pedigree, which is a diagram that shows the line of inheritance of a certain trait through generation. On Friday, we learned about sex-linked disease, which is a disease related to the chromosome of male and female. Female’s chromosome is homozygous with xx chromosome, while male’s chromosome is homozygous with xy chromosome. The gene on male’s x chromosome will be expressed in their phenotype even if its recessive. Most of the sex-linked disease are x-linked because there are 120 genes are known to be x-linked. Example of the disease is hemophilia, which is a disease of blood clotting inability and minor cut cause severe bleeding, mostly happens in male because if female get affected on one of its x chromosome, female still have other x chromosome to replace the mutated chromosome’s function, but male only have one x chromosome and the y chromosome cannot replace the mutated x chromosome’s function. Color blindness is an x-linked disease where people cannot differentiate red and green at the same time, it mostly occur on males due to same cause with hemophilia. Muscular dystrophy is an x-linked disease where the muscle weaken and get worse its year, causing them to survive no longer than thirty, it mostly occur on males due to the same cause with hemophilia and color blindness. Lastly, hypertrichosis is a y-linked disease where our ear grows excessive hair, occurs only in male since female does not have y chromosome.
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AuthorName: Astrida Nayla Archives
April 2016
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