A gene showing codominance has

(A)alleles that are recessive to each other
(B)both alleles independently expressed in the heterozygote
(C)one allele dominant on the other
(D)alleles tightly linked on the same chromosome

The NCERT line that answers it

Verbatim line

But when $I^A$ and $I^B$ are present together they both express their own types of sugars: this is because of co-dominance.

Chapter: Principles of Inheritance and Variation
Section: 4.2.2.2 Co-dominance

The answer appears as a continuous sentence in NCERT. This is that sentence.

How this line gives the answer

3333, emb=1.0, combined=0.7333). Verified: high — The span explicitly states that when IA and IB alleles are present together, 'they both express their own types of sugars: this is because of co-dominance,' which directly matches option B's definition of codominance as both alleles independently expressed in the heterozygote.

We did this for 1,565 questions.

Every one traced to the exact sentence in NCERT that answers it, including 90% of the 2026 paper. Sit a mock on the real NEET 2027 computer interface and every mark you drop comes back with its line attached.

Take the free 5-minute check More from this chapter

Question text is reproduced from the published NEET 2015 paper for study and commentary. NCERT text is quoted, not redistributed; textbooks remain at ncert.nic.in. Our mapping method, including its measured error rates, is published at /methodology.