Sickle-cell anaemia: normal vs sickle RBCs and β-chainदात्र कोशिका अरक्तता: सामान्य बनाम हँसिया RBC और β-शृंखला
NCERT Fig 4.15 · Class 12 Biology · Chapter 4 · interactive diagram
📖 Read Ch 4 with this diagramइस डायग्राम के साथ अध्याय 4 पढ़ेंIs diagram ke saath Ch 4 padhiyeAll diagramsसभी डायग्रामSaare diagrams
Parts and their functions
- Normal RBCs (सामान्य RBC) — Biconcave discs that carry oxygen.
- Sickle-shaped RBCs (हँसिया आकार की RBC) — HbS polymerises at low oxygen tension → RBC changes from a biconcave disc to an elongated sickle shape.
- β-globin chain of HbA (normal) (HbA की β-ग्लोबिन शृंखला (सामान्य)) — Positions 1–7: Val-His-Leu-Thr-Pro-Glu-Glu. Glutamic acid (Glu) is at position 6.
- β-globin chain of HbS (sickle) (HbS की β-ग्लोबिन शृंखला (दात्र)) — Glu is replaced by valine (Val) at the 6th position — a point mutation. Autosomal recessive: the disease shows only in HbS HbS individuals.
- Codon change GAG → GUG (कोडॉन बदलाव GAG → GUG) — A single base substitution in the 6th codon of the β-globin gene (GAG → GUG) changes Glu to Val.
Original diagram drawn by Simple Learning Hub, based on NCERT Fig 4.15. Report a mistake