Biology Genetics

4.1.1 State that eukaryote chromosomes are made of DNA and proteins. eucaryote chromosomes are made of DNA and proteins. 4.1.2 Define ing rosy-cheekeddenedient, allele and genome. cistron: a heritable factor that controls a specific characteristic. allele: one specific form of a factor, differing from other alleles by one or a few bases only and occupying the selfsame(prenominal) gene locus as other alleles of the gene. Genome: the whole of the genetical discipline of an organism. 4.1.3 Define gene magnetic variation. Gene mutation: a careen to the base sequence of a gene. 4.1.4 Explain the resultant of a base reversal mutation in apprisal to the processes of organisation and translation, using the example of sickle- jail booth anemia. Sickle cell anaemia is a genetic disease that affects red product line cells in the body. It is due to a mutation on the Hb gene which codes for a polypeptide of 146 amino group caustics which is part of haemoglobin (haemo globin is an important protein division in red blood cells). In sickle cell anaemia the codon GAG found in the normal Hb gene is mutated to GTG. This is called a base substitution mutation as adenine (A) is replaced by thymine (T). This promoter that when the mutated gene is transcribed, a codon in the courier ribonucleic acid impart be different.

quite of the normal codon GAG, the messenger RNA provide contain the codon GUG. This in turn will result in a slip during translation. In a healthy somebody the codon GAG on the messenger RNA matches with the anticodon CUC on the designate RNA carrying the amino acid glutamic acid. However, if the mutated gene is have past GUG on the mess enger RNA matches with the anticodon CAC on ! the transfer RNA which carries the amino acid valine. So the base substitution mutation has caused glutamic acid to be replaced by valine on the sixth stick on the polypeptide. This results in haemoglobin S being present in red blood cells instead of the normal haemoglobin A. This has an effect on the phenotype as instead of normal halo shaped red blood cells...If you want to get a full essay, orderliness it on our website: OrderEssay.net

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