For all the students preparing for the Bihar Board Class 12 Biology 2026 Exam, this post will be a complete preparation guide for your objective section. Biology is one of the key scoring subjects in Class 12, but it requires a clear understanding of concepts and continuous practice of objective-type questions.
To help you perform your best in the upcoming exam, we’ve compiled the 75 most important objective questions with answers based on the latest Bihar Board syllabus and previous year papers. Each question has been carefully selected to strengthen your conceptual clarity and improve your exam-time confidence.
Bihar Board Class 12 Biology 2026 – 75 Most Important Objective Questions with Answers
Q1. Photosynthesis mainly occurs in which part of the plant?
(a) Root
(b) Stem
(c) Leaf
(d) Flower
Answer: Leaf
Q2. Which pigment is responsible for the green color in plants?
(a) Xanthophyll
(b) Carotene
(c) Chlorophyll
(d) Anthocyanin
Answer: Chlorophyll
Q3. The functional unit of the kidney is:
(a) Nephron
(b) Alveolus
(c) Neuron
(d) Glomerulus
Answer: Nephron
Q4. Which part of the brain controls body balance?
(a) Cerebrum
(b) Cerebellum
(c) Medulla
(d) Pons
Answer: Cerebellum
Q5. The process of converting milk into curd is caused by:
(a) Virus
(b) Bacteria
(c) Protozoa
(d) Fungi
Answer: Bacteria
Q6. In which organ of the human body is insulin produced?
(a) Liver
(b) Pancreas
(c) Kidney
(d) Heart
Answer: Pancreas
Q7. The powerhouse of the cell is:
(a) Ribosome
(b) Nucleus
(c) Mitochondria
(d) Lysosome
Answer: Mitochondria
Q8. Which part of the human body is affected by tuberculosis?
(a) Liver
(b) Lungs
(c) Kidney
(d) Brain
Answer: Lungs
Q9. Which of the following is a non-communicable disease?
(a) Malaria
(b) Tuberculosis
(c) Diabetes
(d) Cholera
Answer: Diabetes
Q10. Which vitamin is produced in the human skin by sunlight?
(a) Vitamin A
(b) Vitamin B
(c) Vitamin C
(d) Vitamin D
Answer: Vitamin D
Q11. The study of heredity is called:
(a) Ecology
(b) Genetics
(c) Cytology
(d) Morphology
Answer: Genetics
Q12. The human heart has how many chambers?
(a) Two
(b) Three
(c) Four
(d) Five
Answer: Four
Q13. Which organ purifies the blood in the human body?
(a) Heart
(b) Kidney
(c) Liver
(d) Lungs
Answer: Kidney
Q14. DNA stands for:
(a) Deoxyribonucleic Acid
(b) Dioxyribonucleic Acid
(c) Deoxynitric Acid
(d) None of these
Answer: Deoxyribonucleic Acid
Q15. Which part of the plant conducts food?
(a) Xylem
(b) Phloem
(c) Cambium
(d) Cortex
Answer: Phloem
Q16. The largest gland in the human body is:
(a) Thyroid
(b) Pancreas
(c) Liver
(d) Salivary gland
Answer: Liver
Q17. Blood group was discovered by:
(a) Mendel
(b) Landsteiner
(c) Darwin
(d) Morgan
Answer: Landsteiner
Q18. Energy in biological systems is stored in:
(a) Joule
(b) Calorie
(c) ATP
(d) Newton
Answer: ATP
Q19. The process of cell division that produces gametes is called:
(a) Mitosis
(b) Meiosis
(c) Binary fission
(d) Fragmentation
Answer: Meiosis
Q20. Which gas is released during photosynthesis?
(a) Carbon dioxide
(b) Oxygen
(c) Nitrogen
(d) Hydrogen
Answer: Oxygen
Q21. The cell organelle responsible for protein synthesis is:
(a) Ribosome
(b) Lysosome
(c) Nucleus
(d) Mitochondria
Answer: Ribosome
Q22. The basic structural and functional unit of life is:
(a) Organ
(b) Cell
(c) Tissue
(d) System
Answer: Cell
Q23. The exchange of gases in humans takes place in:
(a) Bronchi
(b) Alveoli
(c) Trachea
(d) Lungs
Answer: Alveoli
Q24. The human skeleton is made up of how many bones?
(a) 200
(b) 206
(c) 210
(d) 208
Answer: 206
Q25. Which blood group is called a universal donor?
(a) A
(b) AB
(c) O
(d) B
Answer: O
Q26. Which blood group is called a universal recipient?
(a) O
(b) AB
(c) A
(d) B
Answer: AB
Q27. The study of microorganisms is called:
(a) Botany
(b) Zoology
(c) Microbiology
(d) Anatomy
Answer: Microbiology
Q28. The father of genetics is:
(a) Darwin
(b) Mendel
(c) Lamarck
(d) Morgan
Answer: Mendel
Q29. Which of the following is a parasite?
(a) Cow
(b) Deer
(c) Lice
(d) Elephant
Answer: Lice
Q30. The chemical used to test starch in food is:
(a) Benedict’s reagent
(b) Iodine
(c) Alcohol
(d) Acid
Answer: Iodine
Q31. The plant hormone responsible for cell elongation is:
(a) Cytokinin
(b) Auxin
(c) Gibberellin
(d) Abscisic acid
Answer: Auxin
Q32. The number of chromosomes in human body cells is:
(a) 23
(b) 46
(c) 22
(d) 44
Answer: 46
Q33. Which part of the brain controls heartbeat and breathing?
(a) Cerebrum
(b) Medulla oblongata
(c) Cerebellum
(d) Pons
Answer: Medulla oblongata
Q34. Which organ secretes bile?
(a) Liver
(b) Pancreas
(c) Stomach
(d) Kidney
Answer: Liver
Q35. The smallest living unit is:
(a) Atom
(b) Molecule
(c) Cell
(d) Organ
Answer: Cell
Q36. Which blood cells help in clotting of blood?
(a) RBC
(b) WBC
(c) Platelets
(d) Plasma
Answer: Platelets
Q37. The process of removal of waste from the body is called:
(a) Respiration
(b) Excretion
(c) Digestion
(d) Absorption
Answer: Excretion
Q38. Which vitamin prevents night blindness?
(a) Vitamin A
(b) Vitamin B
(c) Vitamin C
(d) Vitamin D
Answer: Vitamin A
Q39. The organism that prepares its own food is called:
(a) Parasite
(b) Saprophyte
(c) Autotroph
(d) Heterotroph
Answer: Autotroph
Q40. The smallest bone in the human body is:
(a) Stapes
(b) Femur
(c) Tibia
(d) Radius
Answer: Stapes
Q41. The longest bone in the human body is:
(a) Femur
(b) Humerus
(c) Tibia
(d) Fibula
Answer: Femur
Q42. Which gland is known as the “Master Gland”?
(a) Thyroid
(b) Pituitary
(c) Pancreas
(d) Adrenal
Answer: Pituitary
Q43. The process by which plants lose water through leaves is:
(a) Photosynthesis
(b) Transpiration
(c) Respiration
(d) Guttation
Answer: Transpiration
Q44. Which part of the flower develops into fruit?
(a) Ovary
(b) Ovule
(c) Stamen
(d) Pistil
Answer: Ovary
Q45. The site of fertilization in humans is:
(a) Ovary
(b) Uterus
(c) Oviduct
(d) Cervix
Answer: Oviduct
Q46. Which of the following is a renewable resource?
(a) Coal
(b) Petroleum
(c) Water
(d) Natural gas
Answer: Water
Q47. The main excretory product in humans is:
(a) Urea
(b) Ammonia
(c) Uric acid
(d) Carbon dioxide
Answer: Urea
Q48. Which element is essential for formation of bones and teeth?
(a) Sodium
(b) Potassium
(c) Calcium
(d) Iron
Answer: Calcium
Q49. Which disease is caused by the deficiency of iodine?
(a) Goitre
(b) Scurvy
(c) Rickets
(d) Anaemia
Answer: Goitre
Q50. The plant that traps insects is:
(a) Rose
(b) Venus Flytrap
(c) Mango
(d) Neem
Answer: Venus Flytrap
Q51. The energy currency of the cell is:
(a) ADP
(b) AMP
(c) ATP
(d) NADH
Answer: ATP
Q52. The deficiency of iron causes:
(a) Goitre
(b) Anaemia
(c) Rickets
(d) Scurvy
Answer: Anaemia
Q53. Which enzyme is present in saliva?
(a) Pepsin
(b) Amylase
(c) Trypsin
(d) Lipase
Answer: Amylase
Q54. The respiratory pigment in human blood is:
(a) Haemoglobin
(b) Myoglobin
(c) Chlorophyll
(d) Melanin
Answer: Haemoglobin
Q55. Which part of the ear helps in hearing?
(a) Cochlea
(b) Eardrum
(c) Pinna
(d) Ear canal
Answer: Cochlea
Q56. The largest artery in the human body is:
(a) Vein
(b) Aorta
(c) Capillary
(d) Pulmonary artery
Answer: Aorta
Q57. Which organism converts nitrogen into a usable form for plants?
(a) Fungi
(b) Rhizobium
(c) Algae
(d) Amoeba
Answer: Rhizobium
Q58. The process of photosynthesis takes place in which cell organelle?
(a) Mitochondria
(b) Chloroplast
(c) Ribosome
(d) Nucleus
Answer: Chloroplast
Q59. The basic unit of classification is:
(a) Species
(b) Genus
(c) Family
(d) Order
Answer: Species
Q60. The human brain is protected by:
(a) Skull
(b) Ribs
(c) Spine
(d) Cranium
Answer: Skull (Cranium)
Q61. The largest cell in the human body is:
(a) Nerve cell
(b) Muscle cell
(c) Ovum
(d) Blood cell
Answer: Ovum
Q62. The smallest cell in the human body is:
(a) Nerve cell
(b) Sperm
(c) RBC
(d) Platelet
Answer: Sperm
Q63. The process of formation of gametes is known as:
(a) Fertilization
(b) Gametogenesis
(c) Zygote formation
(d) Budding
Answer: Gametogenesis
Q64. Which of the following is an example of a decomposer?
(a) Fungus
(b) Tiger
(c) Lion
(d) Deer
Answer: Fungus
Q65. The red color of blood is due to:
(a) Plasma
(b) Haemoglobin
(c) Iron
(d) RBC membrane
Answer: Haemoglobin
Q66. The cell wall of plants is made up of:
(a) Protein
(b) Lipid
(c) Cellulose
(d) Chitin
Answer: Cellulose
Q67. Which plant shows nitrogen fixation?
(a) Wheat
(b) Pea
(c) Rice
(d) Maize
Answer: Pea
Q68. The term “Survival of the fittest” was given by:
(a) Darwin
(b) Lamarck
(c) Mendel
(d) Morgan
Answer: Darwin
Q69. Which organ filters blood in humans?
(a) Liver
(b) Kidney
(c) Heart
(d) Lungs
Answer: Kidney
Q70. The main function of white blood cells is:
(a) Transport oxygen
(b) Blood clotting
(c) Fight infection
(d) Carry nutrients
Answer: Fight infection
Q71. Which plant part absorbs water and minerals?
(a) Stem
(b) Root
(c) Leaf
(d) Flower
Answer: Root
Q72. The chemical formula of glucose is:
(a) C₆H₁₂O₆
(b) C₂H₆O
(c) C₄H₁₀
(d) C₆H₆
Answer: C₆H₁₂O₆
Q73. The process of respiration occurs in which organelle?
(a) Nucleus
(b) Mitochondria
(c) Ribosome
(d) Lysosome
Answer: Mitochondria
Q74. Which enzyme helps in the digestion of proteins in the stomach?
(a) Pepsin
(b) Lipase
(c) Amylase
(d) Maltase
Answer: Pepsin
Q75. The main nitrogenous waste in humans is:
(a) Ammonia
(b) Urea
(c) Uric acid
(d) Carbon dioxide
Answer: Urea
Top 10 FAQs – Bihar Board Class 12 Biology 2026
Q1. How many objective questions come in Bihar Board Class 12 Biology exam?
Answer: The Bihar Board Biology paper usually contains 35 to 40 objective questions carrying 1 mark each.
Q2. What is the total marks of Biology paper in Bihar Board Class 12?
Answer: The Biology paper carries 70 marks for theory and 30 marks for practicals, totaling 100 marks.
Q3. Are these 75 questions enough for revision?
Answer: These 75 questions cover the most important concepts. However, students should also solve model papers for full preparation.
Q4. What are the most important chapters for Class 12 Biology Bihar Board?
Answer: Key chapters include Reproduction, Genetics, Evolution, Human Health and Disease, Biotechnology, and Ecology.
Q5. What type of objective questions are asked?
Answer: Most questions are conceptual, definition-based, and application-based MCQs from the NCERT syllabus.
Q6. How can I score 90+ in Biology?
Answer: Focus on NCERT, revise definitions, diagrams, and practice all MCQs regularly. Attempt previous year questions for accuracy.
Q7. Is NCERT book enough for Bihar Board Biology?
Answer: Yes, the NCERT textbook is the primary and sufficient resource for scoring good marks in Biology.
Q8. How much time should I give to Biology daily?
Answer: Spend at least 2 hours daily revising important concepts and solving objective questions.
Q9. Will these MCQs come directly in the 2026 exam?
Answer: Many of these questions are based on previous year patterns, so similar questions are highly likely to appear.
Q10. Where can I find Bihar Board sample papers for Class 12 Biology?
Answer: Students can download official sample papers from the Bihar School Examination Board (BSEB) website or refer to trusted educational portals.
Conclusion-Bihar Board Class 12 Biology 2026
This comprehensive collection of 75 Most Important Objective Questions for Bihar Board Class 12 Biology 2026 will help you strengthen your understanding of key topics and prepare effectively for the exam.
Stay consistent, revise daily, and keep testing yourself through objective questions — success will surely follow!
Finally we are Completed Bihar Board Class 12 Biology 2026 Questions And Faqs.