ABO blood groups: multiple alleles and co-dominanceABO रुधिर वर्ग: बहुयुग्मविकल्पी और सह-प्रभाविता
NCERT Table 4.2 · 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
- Three alleles of gene I (जीन I के तीन युग्मविकल्पी) — Gene I has 3 alleles: Iᴬ and Iᴮ each make a slightly different sugar on the RBC surface; i makes no sugar. Each person carries any two.
- Group A (IᴬIᴬ or Iᴬi) (A वर्ग (IᴬIᴬ या Iᴬi)) — Iᴬ is completely dominant over i, so Iᴬi is also group A.
- Group B (IᴮIᴮ or Iᴮi) (B वर्ग (IᴮIᴮ या Iᴮi)) — Iᴮ is completely dominant over i, so Iᴮi is also group B.
- Group AB (IᴬIᴮ) — co-dominance (AB वर्ग (IᴬIᴮ) — सह-प्रभाविता) — Iᴬ and Iᴮ both express: the RBCs carry both A and B sugars. F1 resembles both parents = co-dominance.
- Group O (ii) (O वर्ग (ii)) — Only ii gives group O — no sugar is made.
- 6 genotypes, 4 phenotypes (6 जीनोटाइप, 4 फीनोटाइप) — 3 alleles give 6 genotypes (IᴬIᴬ, Iᴬi, IᴮIᴮ, Iᴮi, IᴬIᴮ, ii) but only 4 blood groups. ABO is also an example of multiple alleles.
Original diagram drawn by Simple Learning Hub, based on NCERT Table 4.2. Report a mistake