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.
allelomorph: one specific form of a gene, 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 information of an organism.
4.1.3 Define gene mutation.
Gene mutation: a change to the base sequence of a gene.
4.1.4 Explain the resultant of a base substitution mutation in apprisal to the processes of transcription and translation, using the example of sickle- jail cell anemia.
Sickle cell anaemia is a genetic disease that affects red blood 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 (haemoglobin 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 means that when the mutated gene is transcribed, a codon in the courier RNA will be different.



quite of the normal codon GAG, the messenger RNA will contain the codon GUG. This in turn will result in a slip during translation. In a healthy individual the codon GAG on the messenger RNA matches with the anticodon CUC on the transfer RNA carrying the amino acid glutamic acid. However, if the mutated gene is present then GUG on the messenger 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 position 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 donut shaped red blood cells...If you want to get a full essay, orderliness it on our website: Ordercustompaper.com



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