2018 source guide · Chemistry

NEET 2018 Chemistry Biomolecules Questions

Use this page to connect the official 2018 paper with current Chemistry practice. NeetVellum does not claim a chapter appeared in that paper until the official question and final key have been mapped.

Practice 100 verified questions →Check official NTA archive ↗

What to master

carbohydrates, proteins, enzymes, vitamins and nucleic acids.

Original practice preview

These are current-syllabus NeetVellum questions, shown separately from historical-paper provenance.

Example 1 · difficulty 3/5

Amylopectin, the major fraction of starch, is a branched polymer of α-D-glucose units. The linkages responsible specifically for its branching points are:

A. C1–C4 glycosidic linkages throughout the molecule
B. C1–C6 glycosidic linkages occurring on a backbone held by C1–C4 linkages
C. C1–C2 glycosidic linkages
D. β-glycosidic C1–C4 linkages, as found in cellulose

Example 2 · difficulty 4/5

Glucose decolourises bromine water to give gluconic acid, yet it fails to give Schiff's test and does not form the characteristic addition product with sodium hydrogensulphite. The most consistent explanation for these observations is:

A. glucose actually possesses a ketonic group, since ketoses also reduce bromine water
B. glucose already contains a carboxylic acid group, which bromine water merely oxidises further
C. in solution glucose exists predominantly as a cyclic hemiacetal, so free aldehydic character is greatly diminished, although mild oxidation still reveals the –CHO group
D. the tests fail because glucose is simply a polyhydroxy compound with no carbonyl group whatsoever

Example 3 · difficulty 1/5

A carbohydrate cannot be hydrolysed into simpler carbohydrate units. How should it be classified?

A. Monosaccharide
B. Disaccharide
C. Oligosaccharide
D. Polysaccharide

The evidence-first practice loop

1. Verify provenanceOfficial paper and final key before accepting a PYQ label.
2. Attempt closed-bookExpose the concept or execution gap before rereading.
3. Repair and returnClassify the miss and re-practice after a delay.

Canonical chapter practice

Biomolecules →

Frequently asked questions

Are these official NEET 2018 Chemistry Biomolecules PYQs?

No. The previews are original NeetVellum practice questions. A historical item receives a PYQ label only after its official paper and authoritative final answer key are attached. Use the official archive for the source paper.

How should I use the NEET 2018 paper?

Solve the official paper under its original timing, verify against the final key, classify every miss, and then use the linked current-syllabus practice bank to repair the exposed concept.