2025 source guide · Biology

NEET 2025 Biology Plant Physiology Questions

Use this page to connect the official 2025 paper with current Biology practice. NeetVellum does not claim a chapter appeared in that paper until the official question and final key have been mapped.

What to master

photosynthesis, respiration, growth and hormonal control.

Original practice preview

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

Example 1 · difficulty 2/5

Which statement correctly distinguishes Ingenhousz’s contribution from Priestley’s earlier work?

  • A. Ingenhousz discovered starch formation, whereas Priestley discovered chlorophyll.
  • B. Ingenhousz identified sunlight and green plant parts as necessary for oxygen evolution, whereas Priestley showed that plants could restore altered air.
  • C. Ingenhousz traced oxygen to water, whereas Priestley separated sunlight into a spectrum.
  • D. Ingenhousz located carbon fixation in the stroma, whereas Priestley located pigments in thylakoids.

Example 2 · difficulty 2/5

Why is a plant usually kept in darkness before a Sachs-type experiment on starch formation?

  • A. To remove chlorophyll from the leaves
  • B. To stop the leaf from taking up carbon dioxide permanently
  • C. To use up previously stored starch so that newly formed starch can be attributed to the experimental light treatment
  • D. To fill the chloroplasts with oxygen before illumination

Example 3 · difficulty 3/5

In Engelmann’s experiment, why were aerobic bacteria suitable biological indicators for constructing an action spectrum?

  • A. They emitted different colours at different wavelengths.
  • B. They supplied carbon dioxide only to portions receiving green light.
  • C. They converted all incident wavelengths into red light for the alga.
  • D. They moved toward regions with greater oxygen concentration, revealing wavelengths that drove photosynthesis most effectively.

The evidence-first practice loop

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

Canonical chapter practice

Frequently asked questions

Are these official NEET 2025 Biology Plant Physiology 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 2025 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.

Built by NeetVellum · original practice, explicit provenance, no fabricated PYQ claims.
NEET 2025 Biology Plant Physiology Questions · NeetVellum