Explore how a beta-haemoglobin mutation changes an mRNA codon, amino acid and red-cell oxygen transport in IB Biology SL D1.2.11.
Explain the causes and consequences of sickle-cell anemia.
(point) mutation of gene for hemoglobin;
CTC to CAC / GAG to GTG / substitution of T/thymine with A/adenine;
mRNA copy of gene is GUG instead of GAG;
valine instead of glutamic acid;
(in homozygotes) red blood cells become sickle-shaped;
(in homozygotes) less oxygen carried;
(in homozygotes) red blood cells do not survive long / burst / block blood vessels/capillaries / circulatory problems may cause pain/organ failure/example of symptom;
heterozygotes have malaria resistance;