IBDP CORE>TOPIC 4>GENETICS>4.1CHROMOSOMES, GENES, ALLELES AND MUTATIONS
https://askabiologist.asu.edu/monster-maker-game/play.html
Open the build a monster page - read the information and build the monster.
After you finish building the monster, you have name it and save it. Then upload on managebac. The first person to upload gets full 20 points.
Build a monster
Open the build a monster page - read the information and build the monster.
After you finish building the monster, you have name it and save it. Then upload on managebac. The first person to upload gets full 20 points.
Build a monster
Explain the meaning of the term base substitution and, using a human example, how a single base substitution can have very large effects. 9 marks |
Explain, using sickle cell anemia as an example, the consequences of a base substitution mutation with regard to transcription and translation 8marks
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Changing one base to another in a gene is called Base substitution;
Thus a new allele of the gene is produced. Then the mRNA transcribed from the gene will have one base substitution; Therefore one polypeptide / protein may have one amino acid substitution; This polypeptide / protein may function differently and cause the phenotype of the individual to be different; In sickle cell anaemia; GTG to GAG; valine to glutamic acid; structure of haemoglobin affected; haemoglobin molecules link together (at low oxygen levels); red blood cells become distorted / sickle shape / anaemia; malaria resistance in heterozygotes. |
Transcription is the production of mRNA from DNA template;
DNA sequence determines mRNA sequence; translation is the production of a polypeptide using mRNA; which determines polypeptide sequence; gene mutation is a change in the base sequence of a gene;substitution is when a single base is changed into another base; This leads to a different mRNA sequence; which may change the amino acid sequence in the polypeptide;in sickle-cell anemia, glutamic acid/glu is replaced by valine/val / polar by non-polaramino acid; which affects hemoglobin conformation/shape / function;sickling occurs in low oxygen conditions/sickle cells carry less oxygen |