Preparing for the Bihar Board Class 12th Biology exam requires strong command over objective-type questions because these MCQs directly boost your score. To help you score full marks in the objective section, we have prepared 75 most important objective questions based on the latest Bihar Board syllabus.

This blog includes:

• 75 important MCQs
• Four options for every question
• Correct answers for revision
• Covering chapters like Genetics, Evolution, Ecology, Reproduction, Cell Biology, Biotechnology & More.

Let’s start your preparation with this full question bank.

Bihar Board Class 12th Biology 75 Objective Question With Answers | Complete MCQ Set 2025

Bihar board class 12th biology 75 objective question (With Answers)

Below are all 75 objective questions in one place.

1. The basic unit of life is—

a) Tissue
b) Organ
c) Cell
d) Chromosome
Answer: c) Cell

2. Cell theory was proposed by—

a) Darwin
b) Schleiden & Schwann
c) Mendel
d) Hooke
Answer: b)

3. Powerhouse of the cell is—

a) Ribosome
b) Mitochondria
c) Nucleus
d) Lysosome
Answer: b)

4. Photosynthesis occurs in—

a) Mitochondria
b) Nucleus
c) Chloroplast
d) Golgi body
Answer: c)

5. Nephron is the functional unit of—

a) Brain
b) Kidney
c) Heart
d) Lungs
Answer: b)

6. Mendel is known as the father of—

a) Evolution
b) Genetics
c) Biology
d) Taxonomy
Answer: b)

7. DNA stands for—

a) Dextrose Nitric Acid
b) Deoxyribo Nucleic Acid
c) Deoxy Nitrous Acid
d) None
Answer: b)

8. Universal donor blood group is—

a) A
b) B
c) AB
d) O
Answer: d)

9. Gas exchange occurs in—

a) Bronchi
b) Trachea
c) Alveoli
d) Larynx
Answer: c)

10. Longest bone in human body is—

a) Tibia
b) Femur
c) Radius
d) Humerus
Answer: b)

11. Insulin is secreted by—

a) Liver
b) Pancreas
c) Kidney
d) Thyroid
Answer: b)

12. Female reproductive part of a flower is—

a) Anther
b) Stamen
c) Pistil
d) Petal
Answer: c)

13. Deficiency of Vitamin C causes—

a) Rickets
b) Scurvy
c) Night blindness
d) Beriberi
Answer: b)

14. Ovulation is the release of—

a) Sperm
b) Ovum
c) Zygote
d) Embryo
Answer: b)

15. Scientific name of human is—

a) Homo erectus
b) Homo habilis
c) Homo sapiens
d) Gorilla gorilla
Answer: c)

16. Hereditary unit is—

a) DNA
b) Chromosome
c) Gene
d) Protein
Answer: c)

17. Malaria is caused by—

a) Virus
b) Bacteria
c) Plasmodium
d) Fungus
Answer: c)

18. Tuberculosis affects primarily—

a) Liver
b) Lungs
c) Eyes
d) Heart
Answer: b)

19. AIDS is caused by—

a) HBV
b) HIV
c) HCV
d) HSV
Answer: b)

20. Amoeba respires through—

a) Lungs
b) Skin
c) Gills
d) Body surface
Answer: d)

21. DNA replication occurs during—

a) G1 phase
b) S phase
c) G2 phase
d) M phase
Answer: b)

22. Example of asexual reproduction—

a) Fertilization
b) Binary fission
c) Pollination
d) Syngamy
Answer: b)

23. Human heart contains—

a) 2 chambers
b) 3 chambers
c) 4 chambers
d) 5 chambers
Answer: c)

24. Enzyme responsible for digestion of protein—

a) Amylase
b) Pepsin
c) Lipase
d) Renin
Answer: b)

25. Vaccine discovery pioneer—

a) Louis Pasteur
b) Alexander Fleming
c) Watson
d) Jenner
Answer: d)

26. RBC life span is—

a) 60 days
b) 100 days
c) 120 days
d) 150 days
Answer: c)

27. Largest organ of human body—

a) Heart
b) Skin
c) Brain
d) Lungs
Answer: b)

28. Site of fertilization in humans—

a) Ovary
b) Fallopian tube
c) Uterus
d) Cervix
Answer: b)

29. Sex-linked disease—

a) Cholera
b) Hemophilia
c) Typhoid
d) Tetanus
Answer: b)

30. Protein digestion begins in—

a) Mouth
b) Stomach
c) Small intestine
d) Large intestine
Answer: b)

31. Plant tissue responsible for transport of food—

a) Xylem
b) Phloem
c) Parenchyma
d) Collenchyma
Answer: b)

32. RNA stands for—

a) Ribo Nucleic Acid
b) Ribo Nitric Acid
c) Ribo Neutral Acid
d) None
Answer: a)

33. Meiosis occurs in—

a) Somatic cells
b) Gametes
c) Nerve cells
d) Blood cells
Answer: b)

34. The process of making food by plants is known as—

a) Respiration
b) Transpiration
c) Photosynthesis
d) Digestion
Answer: c)

35. Which is a viral disease?

a) Polio
b) Leprosy
c) Cholera
d) Typhoid
Answer: a)

36. Genetic material in bacteria is—

a) Nucleus
b) Nucleoid
c) Chromosome
d) RNA only
Answer: b)

37. The father of evolution—

a) Darwin
b) Mendel
c) Lamarck
d) Morgan
Answer: a)

38. Example of excretory product—

a) Oxygen
b) Urea
c) Iron
d) Protein
Answer: b)

39. Normal human body temperature—

a) 36°C
b) 37°C
c) 38°C
d) 35°C
Answer: b)

40. Blood is a type of—

a) Muscle
b) Tissue
c) Fluid
d) Organ
Answer: b)

41. Structural and functional unit of nervous system—

a) Neuron
b) Tendon
c) Ligament
d) Muscle
Answer: a)

42. Which is an example of a pisces?

a) Frog
b) Lizard
c) Fish
d) Snake
Answer: c)

43. Myopia is—

a) Long sightedness
b) Short sightedness
c) Color blindness
d) Cataract
Answer: b)

44. Which vitamin is fat-soluble?

a) Vitamin B
b) Vitamin C
c) Vitamin D
d) Vitamin B12
Answer: c)

45. Example of non-communicable disease—

a) TB
b) Diabetes
c) Influenza
d) Measles
Answer: b)

46. Number of chromosomes in humans—

a) 42
b) 44
c) 46
d) 48
Answer: c)

47. The term ecosystem was coined by—

a) Tansley
b) Lindemann
c) Haeckel
d) Lamarck
Answer: a)

48. Blood clotting vitamin is—

a) Vitamin D
b) Vitamin K
c) Vitamin E
d) Vitamin A
Answer: b)

49. Plants lose water through—

a) Respiration
b) Transpiration
c) Photosynthesis
d) Digestion
Answer: b)

50. Example of amphibian—

a) Snake
b) Crocodile
c) Frog
d) Whale
Answer: c)

51. Largest gland in human body—

a) Liver
b) Thyroid
c) Kidney
d) Pancreas
Answer: a)

52. The smallest bone in human body—

a) Femur
b) Stapes
c) Humerus
d) Tibia
Answer: b)

53. Which organ secretes bile?

a) Liver
b) Pancreas
c) Stomach
d) Kidney
Answer: a)

54. Lens focuses image on—

a) Retina
b) Cornea
c) Iris
d) Optic nerve
Answer: a)

55. Example of abiotic factor—

a) Plants
b) Animals
c) Water
d) Bacteria
Answer: c)

56. The site of photosynthesis in plants—

a) Root
b) Stem
c) Leaf
d) Flower
Answer: c)

57. Which hormone regulates growth?

a) Insulin
b) Thyroxine
c) HGH
d) ADH
Answer: c)

58. Food is stored in plants as—

a) Glucose
b) Starch
c) Protein
d) Fat
Answer: b)

59. Example of protein—

a) Starch
b) Glucose
c) Casein
d) Cellulose
Answer: c)

60. Plant cell wall is made of—

a) Cellulose
b) Chitin
c) Starch
d) Protein
Answer: a)

---

61–75

61. Which is a biotic component?

a) Soil
b) Water
c) Air
d) Plants
Answer: d)

62. First enzyme discovered was—

a) Pepsin
b) Urease
c) Lipase
d) Trypsin
Answer: b)

63. Chlorophyll contains—

a) Iron
b) Nitrogen
c) Magnesium
d) Zinc
Answer: c)

64. Father of modern taxonomy—

a) Linnaeus
b) Darwin
c) Mendel
d) Hooke
Answer: a)

65. Greenhouse gas—

a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Helium
Answer: c)

66. Blood plasma is—

a) Solid
b) Semi-solid
c) Liquid
d) Gas
Answer: c)

67. The flower is a modified—

a) Stem
b) Leaf
c) Root
d) Fruit
Answer: a)

68. The process of water intake by root is—

a) Osmosis
b) Diffusion
c) Transpiration
d) Active transport
Answer: a)

69. Which organ purifies blood?

a) Heart
b) Liver
c) Kidney
d) Lungs
Answer: c)

70. Blood cells that help in clotting—

a) RBC
b) WBC
c) Platelets
d) All
Answer: c)

71. The largest part of the brain—

a) Cerebellum
b) Medulla
c) Cerebrum
d) Pons
Answer: c)

72. Which part controls balance of body?

a) Cerebrum
b) Cerebellum
c) Spinal cord
d) Medulla
Answer: b)

73. Normal human heartbeat per minute—

a) 50–60
b) 60–70
c) 70–80
d) 80–90
Answer: c)

74. Site of protein synthesis—

a) Mitochondria
b) Ribosome
c) Nucleus
d) Golgi body
Answer: b)

75. The cell organelle involved in secretion—

a) Ribosome
b) Golgi apparatus
c) Nucleus
d) Chloroplast
Answer: b)

FAQs – Bihar board class 12th biology 75 objective question

1. What is the best way to prepare for Bihar Board Class 12 Biology objective questions?

The best way to prepare is by practicing previous year question papers, solving important MCQ sets, revising NCERT chapters thoroughly, and focusing on diagrams and definitions. Regular practice increases accuracy and confidence.

2. How many objective questions are asked in Bihar Board Class 12 Biology exam?

Bihar Board generally asks 35 objective questions in the Biology paper. However, students prepare more (75–100 MCQs) to strengthen their score because the objective section covers the entire syllabus.

3. Are these 75 Biology objective questions enough for scoring good marks?

Yes, these 75 questions cover major topics from the syllabus and are excellent for quick revision. However, students should also revise NCERT and practice additional MCQs for maximum scoring.

4. Which chapters are most important for Biology objective questions?

Chapters like Genetics, Evolution, Reproduction, Human Physiology, Biotechnology, Ecology, and Cell Biology are highly important because they contribute a good number of MCQs in the board exam.

5. How can I score full marks in biology objective section?

To score full marks, study NCERT line-by-line, prepare short notes, solve daily objective sets, revise diagrams, and practice chapter-wise mock tests. Repetition is the key to mastering MCQs.

Bihar Board Class 12th Biology 75 Objective Question With Answers

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