If you are looking for Re-NEET 2026 Biology MCQs to sharpen your preparation before June 21, this is the resource you need. Biology carries 360 out of 720 marks in NEET — it is the single highest-scoring section and the one that separates average scores from 600+ scores. These 50 most expected questions for Re-NEET 2026 Biology have been curated based on five-year chapter-wise weightage analysis, NCERT line-level importance, and recurring question patterns from NEET 2021 through 2025. Work through every question, check your answers, and identify the chapters where you are dropping marks.
For a full chapter-wise preparation strategy, refer to our Re-NEET 2026 Biology preparation guide alongside this practice set.
How to Use This Practice Set
- Attempt each question independently before checking the answer
- Note every wrong answer — these point directly to your weak chapters
- Re-read the relevant NCERT paragraph for every incorrect answer
- Revisit this set after 5 days to test retention
Section 1: Genetics and Evolution (Most Expected — 12–15 Questions in NEET)
Q1. Which of the following correctly represents the law of segregation?
- A) Two alleles of a gene separate during gamete formation and reunite randomly at fertilisation
- B) Genes for different traits assort independently
- C) One allele always dominates over another
- D) Alleles do not separate during meiosis
Answer: A Mendel’s Law of Segregation — alleles separate during gamete formation.
Q2. A cross between a homozygous tall plant (TT) and a homozygous dwarf plant (tt) produces F1 plants. When F1 plants are self-pollinated, the ratio of tall to dwarf plants in F2 is:
- A) 1:1
- B) 3:1
- C) 1:3
- D) 2:1
Answer: B Classic monohybrid cross — F2 phenotypic ratio is 3:1.
Q3. In which of the following conditions does codominance occur?
- A) Tt genotype in Mendel’s pea plants
- B) ABO blood group system — genotype IAIB
- C) Incomplete dominance in snapdragon flower colour
- D) Homozygous dominant genotype
Answer: B IAIB expresses both A and B antigens equally — classic codominance.
Q4. The term ‘mutation’ was coined by:
- A) Gregor Mendel
- B) Hugo de Vries
- C) Thomas Hunt Morgan
- D) Francis Crick
Answer: B Hugo de Vries coined the term mutation while working with Oenothera lamarckiana.
Q5. Which of the following is NOT a characteristic of the genetic code?
- A) It is universal
- B) It is degenerate
- C) It is overlapping
- D) It is unambiguous
Answer: C The genetic code is non-overlapping — each nucleotide belongs to only one codon.
Q6. Sickle cell anaemia is caused by a point mutation that substitutes:
- A) Glutamic acid with Valine at position 6 of beta-globin chain
- B) Valine with Glutamic acid at position 6 of alpha-globin chain
- C) Lysine with Valine at position 6 of beta-globin chain
- D) Glutamic acid with Alanine at position 6 of beta-globin chain
Answer: A Glutamic acid → Valine substitution at position 6 of the beta-globin chain causes sickle cell anaemia.
Q7. Which evolutionary concept is demonstrated by the presence of analogous organs in different species?
- A) Divergent evolution
- B) Convergent evolution
- C) Co-evolution
- D) Microevolution
Answer: B Analogous organs indicate convergent evolution — similar function, different origin.
Q8. The connecting link between Reptilia and Aves is:
- A) Platypus
- B) Archaeopteryx
- C) Dodo
- D) Lungfish
Answer: B Archaeopteryx showed features of both reptiles (teeth, clawed wings) and birds (feathers).
Section 2: Human Physiology (14–18 Questions Expected)
Q9. Which enzyme initiates protein digestion in the stomach?
- A) Trypsin
- B) Pepsin
- C) Erepsin
- D) Lipase
Answer: B Pepsin, activated from pepsinogen by HCl, begins protein digestion in the stomach.
Q10. The correct sequence of events during muscle contraction according to the sliding filament theory is:
- A) Ca²⁺ release → myosin head binds actin → ATP hydrolysis → power stroke
- B) ATP hydrolysis → Ca²⁺ release → actin binds myosin → power stroke
- C) Power stroke → Ca²⁺ release → myosin binds actin → ATP hydrolysis
- D) Ca²⁺ release → ATP hydrolysis → actin slides → troponin inhibition
Answer: A Ca²⁺ released from sarcoplasmic reticulum triggers tropomyosin shift, allowing myosin-actin binding and power stroke.
Q11. What is the oxygen-carrying capacity of one gram of haemoglobin?
- A) 1.2 mL
- B) 1.34 mL
- C) 2.0 mL
- D) 0.98 mL
Answer: B One gram of haemoglobin carries 1.34 mL of oxygen — a frequently tested NCERT fact.
Q12. Which part of the nephron is impermeable to water but permeable to electrolytes?
- A) Proximal Convoluted Tubule
- B) Descending limb of loop of Henle
- C) Ascending limb of loop of Henle
- D) Collecting duct
Answer: C The ascending limb of loop of Henle is impermeable to water but allows electrolyte reabsorption.
Q13. The pacemaker of the human heart is:
- A) AV node
- B) Bundle of His
- C) SA node
- D) Purkinje fibres
Answer: C The Sino-Atrial (SA) node generates the impulse that initiates heartbeat — it is the pacemaker.
Q14. Which hormone is responsible for the ‘fight or flight’ response?
- A) Thyroxine
- B) Insulin
- C) Adrenaline (Epinephrine)
- D) Cortisol
Answer: C Adrenaline, secreted by the adrenal medulla, triggers the fight or flight response.
Q15. The functional unit of the kidney is the:
- A) Glomerulus
- B) Nephron
- C) Bowman’s capsule
- D) Loop of Henle
Answer: B The nephron is the structural and functional unit of the kidney.
Q16. Which of the following is correctly matched?
- A) Rods — colour vision
- B) Cones — dim light vision
- C) Rods — dim light vision
- D) Cones — peripheral vision
Answer: C Rods contain rhodopsin and function in low-light (dim) vision. Cones handle colour and bright-light vision.
Section 3: Molecular Biology — DNA Replication, Transcription, Translation
Q17. The enzyme responsible for relieving the tension ahead of the replication fork during DNA replication is:
- A) DNA Ligase
- B) Helicase
- C) Topoisomerase
- D) Primase
Answer: C Topoisomerase cuts and rejoins DNA strands to relieve torsional stress ahead of the replication fork.
Q18. Which of the following RNA types acts as an adapter molecule during translation?
- A) mRNA
- B) rRNA
- C) tRNA
- D) snRNA
Answer: C tRNA carries amino acids and matches codons on mRNA through its anticodon — it is the adapter molecule.
Q19. The lac operon model was proposed by:
- A) Watson and Crick
- B) Jacob and Monod
- C) Hershey and Chase
- D) Meselson and Stahl
Answer: B Jacob and Monod proposed the lac operon model of gene regulation in E. coli in 1961.
Q20. Which experiment proved that DNA is the genetic material in bacteriophage?
- A) Griffith’s experiment
- B) Avery, MacLeod and McCarty experiment
- C) Hershey-Chase experiment
- D) Meselson-Stahl experiment
Answer: C Hershey and Chase used radioactive isotopes (³²P and ³⁵S) to prove DNA is the genetic material in T2 phage.
Section 4: Plant Physiology
Q21. Which of the following is the correct site of photosystem I and photosystem II?
- A) Stroma — PS I, Grana — PS II
- B) Grana — PS I and PS II both
- C) PS II on grana thylakoids, PS I on stroma lamellae
- D) Stroma — PS I and PS II both
Answer: C PS II is located on grana thylakoids; PS I is on stroma lamellae (stroma thylakoids).
Q22. Which plant hormone is known as the ‘stress hormone’?
- A) Gibberellin
- B) Cytokinin
- C) Ethylene
- D) Abscisic Acid (ABA)
Answer: D ABA is called the stress hormone — it promotes stomatal closure during water stress.
Q23. The C4 pathway (Hatch-Slack cycle) has its primary CO₂ fixation in:
- A) Bundle sheath cells
- B) Mesophyll cells
- C) Guard cells
- D) Epidermal cells
Answer: B In C4 plants, CO₂ is initially fixed in mesophyll cells by PEP carboxylase, forming oxaloacetate (OAA).
Q24. Photoperiodism was first studied in which plant?
- A) Tobacco (Nicotiana tabacum)
- B) Xanthium
- C) Hyoscyamus
- D) Arabidopsis
Answer: A Garner and Allard first studied photoperiodism in Nicotiana tabacum (Maryland Mammoth).
Q25. Which of the following is a long-day plant?
- A) Chrysanthemum
- B) Xanthium
- C) Henbane (Hyoscyamus niger)
- D) Tobacco (Maryland Mammoth)
Answer: C Henbane (Hyoscyamus niger) requires long days (short nights) to flower — it is a long-day plant.
Section 5: Cell Biology and Cell Division
Q26. Which phase of meiosis is the longest?
- A) Metaphase I
- B) Anaphase II
- C) Prophase I
- D) Telophase I
Answer: C Prophase I is the longest phase of meiosis, subdivided into Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.
Q27. The powerhouse of the cell is:
- A) Nucleus
- B) Ribosome
- C) Mitochondria
- D) Golgi apparatus
Answer: C Mitochondria produce ATP through oxidative phosphorylation — they are the powerhouse of the cell.
Q28. Which of the following is correct about the fluid mosaic model of the cell membrane?
- A) Proteins are immobile within the lipid bilayer
- B) Lipids form a monolayer with proteins on the outside
- C) Proteins float within a fluid phospholipid bilayer
- D) Carbohydrates form the core of the membrane
Answer: C The fluid mosaic model (Singer and Nicolson, 1972) describes proteins floating in a fluid phospholipid bilayer.
Q29. Ribosomes are the sites of:
- A) Transcription
- B) Replication
- C) Translation
- D) Post-translational modification
Answer: C Ribosomes are the molecular machines where mRNA is translated into proteins.
Q30. Which of the following organelles is absent in prokaryotes?
- A) Ribosome
- B) Cell membrane
- C) Mitochondria
- D) Cell wall
Answer: C Prokaryotes lack membrane-bound organelles including mitochondria, endoplasmic reticulum, and Golgi apparatus.
Section 6: Ecology and Environment
Q31. Which of the following represents a correct food chain?
- A) Hawk → Snake → Frog → Grasshopper → Grass
- B) Grass → Grasshopper → Frog → Snake → Hawk
- C) Grass → Frog → Grasshopper → Snake → Hawk
- D) Grasshopper → Grass → Frog → Snake → Hawk
Answer: B Energy flows from producers (Grass) to primary consumers (Grasshopper) upward through the trophic levels.
Q32. The 10% energy transfer law in an ecosystem was given by:
- A) Lindeman
- B) Odum
- C) Tansley
- D) Elton
Answer: A Raymond Lindeman proposed the 10% law — only 10% of energy is transferred from one trophic level to the next.
Q33. Which biome has the highest biodiversity?
- A) Temperate deciduous forest
- B) Tropical rainforest
- C) Savanna grassland
- D) Coral reef
Answer: B Tropical rainforests have the highest species diversity due to year-round warmth and rainfall.
Q34. The concept of the ecological niche was introduced by:
- A) Charles Darwin
- B) G. Evelyn Hutchinson
- C) Eugene Odum
- D) Robert MacArthur
Answer: B G. Evelyn Hutchinson introduced the modern n-dimensional hypervolume concept of an ecological niche.
Q35. Which of the following is a greenhouse gas?
- A) Nitrogen (N₂)
- B) Oxygen (O₂)
- C) Methane (CH₄)
- D) Argon (Ar)
Answer: C Methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) are major greenhouse gases.
Section 7: Biotechnology
Q36. The enzyme used to join two DNA fragments in recombinant DNA technology is:
- A) Helicase
- B) DNA Ligase
- C) Restriction Endonuclease
- D) DNA Polymerase
Answer: B DNA Ligase forms phosphodiester bonds between DNA fragments — it is the “molecular glue” in recombinant DNA technology.
Q37. The first genetically engineered insulin was produced using:
- A) Saccharomyces cerevisiae
- B) Escherichia coli
- C) Agrobacterium tumefaciens
- D) Bacillus thuringiensis
Answer: B Eli Lilly produced the first recombinant human insulin (Humulin) using E. coli in 1982.
Q38. Bt toxin, used in Bt cotton, is derived from:
- A) Bacillus subtilis
- B) Agrobacterium tumefaciens
- C) Bacillus thuringiensis
- D) Pseudomonas fluorescens
Answer: C The cry genes from Bacillus thuringiensis encode Bt toxin, which is toxic to specific insect larvae.
Q39. PCR (Polymerase Chain Reaction) was developed by:
- A) Watson and Crick
- B) Kary Mullis
- C) Frederick Sanger
- D) Paul Berg
Answer: B Kary Mullis developed PCR in 1983 and was awarded the Nobel Prize in Chemistry in 1993.
Q40. The Ti plasmid used in plant genetic engineering is found in:
- A) Bacillus thuringiensis
- B) Rhizobium leguminosarum
- C) Agrobacterium tumefaciens
- D) Escherichia coli
Answer: C Agrobacterium tumefaciens carries the Ti (tumour-inducing) plasmid used as a vector in plant transformation.
Section 8: Reproduction in Plants and Animals
Q41. Which of the following is NOT a feature of wind-pollinated flowers?
- A) Large, feathery stigma
- B) Light, non-sticky pollen
- C) Bright coloured petals
- D) Single ovule per flower
Answer: C Wind-pollinated flowers are generally dull-coloured and small — bright petals are features of insect-pollinated flowers.
Q42. The correct sequence of embryonic development is:
- A) Zygote → Morula → Blastula → Gastrula
- B) Zygote → Blastula → Morula → Gastrula
- C) Zygote → Gastrula → Morula → Blastula
- D) Morula → Zygote → Blastula → Gastrula
Answer: A Zygote → Morula (solid ball) → Blastula (hollow ball) → Gastrula (three germ layers).
Q43. The acrosome of a sperm contains:
- A) Mitochondria
- B) Nucleus
- C) Hydrolytic enzymes
- D) Flagellum proteins
Answer: C The acrosome contains hydrolytic enzymes (including hyaluronidase) that help the sperm penetrate the egg.
Q44. Which of the following contraceptive methods has the highest efficiency?
- A) Condoms
- B) Cervical cap
- C) Combined oral contraceptive pills
- D) Copper-T IUD
Answer: C Combined oral contraceptive pills (OCPs) have ~99% efficiency when used correctly, making them the most effective among these options.
Q45. Where does fertilisation normally occur in the human female reproductive system?
- A) Uterus
- B) Ovary
- C) Fallopian tube (Ampullary-isthmic junction)
- D) Cervix
Answer: C Fertilisation typically occurs at the ampullary-isthmic junction of the fallopian tube.
Section 9: Biological Classification and Diversity
Q46. Which of the following is a correct characteristic of Kingdom Fungi?
- A) Autotrophic nutrition
- B) Presence of chlorophyll
- C) Cell walls made of chitin
- D) Prokaryotic cell organisation
Answer: C Fungi have cell walls made of chitin — they are heterotrophic, eukaryotic, and lack chlorophyll.
Q47. Who proposed the five-kingdom classification?
- A) Carolus Linnaeus
- B) Ernst Haeckel
- C) R.H. Whittaker
- D) Carl Woese
Answer: C R.H. Whittaker proposed the five-kingdom classification in 1969 — Monera, Protista, Fungi, Plantae, Animalia.
Q48. Which of the following is NOT a characteristic of viruses?
- A) They can replicate only inside a host cell
- B) They contain either DNA or RNA, never both
- C) They have their own ribosomes
- D) They are obligate intracellular parasites
Answer: C Viruses do not have ribosomes — they hijack the host cell’s ribosomes for protein synthesis.
Q49. The antibiotic penicillin is obtained from:
- A) Streptomyces griseus
- B) Penicillium notatum
- C) Aspergillus niger
- D) Rhizopus stolonifer
Answer: B Penicillin was discovered by Alexander Fleming from Penicillium notatum (now classified as P. chrysogenum).
Q50. Which of the following is the correct example of a vestigial organ in humans?
- A) Appendix
- B) Thumb
- C) Femur
- D) Cornea
Answer: A The vermiform appendix is a classic example of a vestigial organ in humans — it has lost its original digestive function through evolution.
Chapter-Wise Distribution of These 50 MCQs
| Chapter / Topic | Questions Covered | NEET Weightage |
|---|---|---|
| Genetics and Evolution | Q1–Q8 | ~12–15 questions |
| Human Physiology | Q9–Q16 | ~14–18 questions |
| Molecular Biology | Q17–Q20 | ~6–8 questions |
| Plant Physiology | Q21–Q25 | ~6–8 questions |
| Cell Biology | Q26–Q30 | ~5–7 questions |
| Ecology | Q31–Q35 | ~7–9 questions |
| Biotechnology | Q36–Q40 | ~5–7 questions |
| Reproduction | Q41–Q45 | ~5–7 questions |
| Classification & Diversity | Q46–Q50 | ~4–6 questions |
What to Do After Attempting These MCQs
Scored 40–50 correct: Your Biology foundation is strong. Focus on NCERT exception-based questions and diagram-based MCQs in the final stretch. Check our 40-day Re-NEET 2026 study plan to pace your remaining revision.
Scored 25–39 correct: You have a solid base but clear chapter-wise gaps. Note every wrong answer, identify the chapters, and spend the next 3–4 days doing a focused NCERT re-read of those specific chapters.
Scored below 25: Biology needs urgent attention. Prioritise Genetics, Human Physiology, and Ecology — these three alone account for roughly 35–40 questions in NEET. Do not spread across all chapters. If you scored below 350 in NEET 2026 and Biology is your weak point, read our guide on what Re-NEET 2026 means for low scorers.
For a subject-wise deep dive into Chemistry and Physics as well, check out our Re-NEET 2026 Chemistry strategy and Re-NEET 2026 Physics preparation guides.
FAQ: Re-NEET 2026 Biology MCQs
Q1. Which chapters are most important for Re-NEET 2026 Biology? Genetics and Evolution, Human Physiology, Molecular Biology, Ecology, and Biotechnology are the highest-weightage chapters. Together they contribute approximately 60–65% of the Biology questions in NEET.
Q2. How many Biology questions are there in NEET 2026? Biology has 100 questions in NEET UG — 50 from Botany and 50 from Zoology — carrying a total of 360 marks (4 marks each).
Q3. Are these MCQs based on NCERT? Yes. All 50 questions in this set are strictly NCERT-based, reflecting the exact type of questions NTA asks in NEET. No question in this set goes beyond NCERT scope.
Q4. How many Biology questions should I aim to attempt correctly in Re-NEET 2026? For a 600+ total score, you need approximately 280–300 marks from Biology (70–75 correct out of 100). For a 650+ score, aim for 310–330 marks from Biology.
Q5. Will Re-NEET 2026 Biology be tougher than the original exam? Most experts expect the Re-NEET 2026 Biology section to be of similar or slightly higher difficulty. Expect more application-based and exception-based questions rather than straightforward recall. Thorough NCERT reading remains the best preparation strategy.