Top 50 Biology MCQs with Answers | NEET, Competitive Exams & School Tests

 Here are 50 multiple-choice questions (MCQs) on biology, along with their correct answers:

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Biology MCQs

1-10: Cell Biology & Genetics

1. What is the powerhouse of the cell?
   a) Ribosome
   b) Nucleus
   c) Mitochondria ✅
   d) Golgi apparatus

2. DNA is made up of repeating units called:
   a) Amino acids
   b) Nucleotides ✅
   c) Fatty acids
   d) Monosaccharides

3. Who discovered the structure of DNA?
   a) Gregor Mendel
   b) Watson and Crick ✅
   c) Charles Darwin
   d) Robert Hooke

4. The basic structural and functional unit of life is:
   a) Organ
   b) Tissue
   c) Cell ✅
   d) Organ system

5. What is the function of ribosomes?
   a) DNA replication
   b) Protein synthesis ✅
   c) Lipid storage
   d) Energy production

6. Which of the following is NOT a type of RNA?
   a) mRNA
   b) tRNA
   c) rRNA
   d) dRNA ✅

7. Mitosis results in:
   a) Four identical cells
   b) Two identical cells ✅
   c) Two different cells
   d) Four different cells

8. Which chromosome determines male gender in humans?
   a) XX
   b) XY ✅
   c) YY
   d) XO

9. What is the full form of DNA?
   a) Deoxyribo Nucleic Acid ✅
   b) Dextrose Nitric Acid
   c) Deoxyribonitric Acid
   d) Double Helix Nucleic Acid

10. The exchange of genetic material between homologous chromosomes during meiosis is called:
    a) Mutation
    b) Transcription
    c) Crossing over ✅
    d) Translation

Biology MCQs: 50 Important Questions with Answers for Exams

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11-20: Human Physiology

11. Which organ is responsible for filtering blood?
    a) Liver
    b) Kidney ✅
    c) Heart
    d) Lungs

12. Which blood cells fight infection?
    a) Red blood cells
    b) White blood cells ✅
    c) Platelets
    d) Plasma

13. The functional unit of the kidney is called:
    a) Alveolus
    b) Nephron ✅
    c) Neuron
    d) Glomerulus

14. Which is the longest bone in the human body?
    a) Humerus
    b) Femur ✅
    c) Tibia
    d) Radius

15. What is the normal pH of human blood?
    a) 5.5
    b) 6.4
    c) 7.4 ✅
    d) 8.2

16. The hormone insulin is produced by which organ?
    a) Liver
    b) Pancreas ✅
    c) Thyroid
    d) Adrenal gland

17. Which part of the brain controls balance and coordination?
    a) Cerebrum
    b) Cerebellum ✅
    c) Medulla
    d) Hypothalamus

18. The main function of the small intestine is:
    a) Digestion
    b) Absorption of nutrients ✅
    c) Water retention
    d) Detoxification

19. Which gas is essential for cellular respiration?
    a) Nitrogen
    b) Carbon dioxide
    c) Oxygen ✅
    d) Helium

20. The normal human body temperature is:
    a) 35°C
    b) 36°C
    c) 37°C ✅
    d) 38°C

50 Biology Multiple Choice Questions (MCQs) with Correct Answers

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21-30: Botany & Ecology

21. Which pigment is responsible for photosynthesis?
    a) Hemoglobin
    b) Chlorophyll ✅
    c) Carotene
    d) Xanthophyll

22. Which plant tissue transports water?
    a) Phloem
    b) Xylem ✅
    c) Epidermis
    d) Parenchyma

23. What is the primary source of energy for plants?
    a) Water
    b) Sunlight ✅
    c) Oxygen
    d) Soil nutrients

24. Which gas is absorbed by plants during photosynthesis?
    a) Oxygen
    b) Carbon dioxide ✅
    c) Nitrogen
    d) Hydrogen

25. Plants store glucose in the form of:
    a) Cellulose
    b) Starch ✅
    c) Protein
    d) Glycogen

26. The process by which plants lose water vapor is called:
    a) Transpiration ✅
    b) Respiration
    c) Photosynthesis
    d) Osmosis

27. What is the main function of stomata?
    a) Absorbing sunlight
    b) Exchanging gases ✅
    c) Storing food
    d) Transporting nutrients

28. An ecosystem consists of:
    a) Only plants
    b) Only animals
    c) Both biotic and abiotic components ✅
    d) Only living organisms

29. Which biome has the highest biodiversity?
    a) Desert
    b) Tundra
    c) Rainforest ✅
    d) Grassland

30. The greenhouse effect is caused by an increase in:
    a) Oxygen
    b) Carbon dioxide ✅
    c) Nitrogen
    d) Hydrogen

Biology Quiz: 50 MCQs with Answers for Competitive Exams & Students

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31-40: Microbiology & Biotechnology

31. Bacteria reproduce by:
    a) Mitosis
    b) Binary fission ✅
    c) Meiosis
    d) Budding

32. Which microorganism causes malaria?
    a) Virus
    b) Bacteria
    c) Protozoa ✅
    d) Fungi

33. The causative agent of tuberculosis is:
    a) Streptococcus
    b) Mycobacterium tuberculosis ✅
    c) Salmonella
    d) E. coli

34. Antibiotics are effective against:
    a) Viruses
    b) Bacteria ✅
    c) Fungi
    d) Protozoa

35. Which vitamin is produced by bacteria in the human gut?
    a) Vitamin A
    b) Vitamin C
    c) Vitamin K ✅
    d) Vitamin D

36. Which part of a virus allows it to attach to a host cell?
    a) Capsid
    b) Envelope
    c) Spike proteins ✅
    d) RNA

37. The first vaccine was developed by:
    a) Alexander Fleming
    b) Edward Jenner ✅
    c) Louis Pasteur
    d) Robert Koch

38. Recombinant DNA technology is used for:
    a) Genetic engineering ✅
    b) Hybridization
    c) Cloning
    d) Photosynthesis

39. What is the full form of PCR in biotechnology?
    a) Polymerase Chain Reaction ✅
    b) Protein Cell Replication
    c) Photo Chemical Reaction
    d) Polypeptide Chromosome Replication

40. Which microorganism is used in making bread?
    a) Virus
    b) Bacteria
    c) Yeast ✅
    d) Algae

Essential 50 Biology MCQs for Exam Preparation (With Answers)

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41-50: Evolution & Miscellaneous

41. The theory of natural selection was proposed by: Charles Darwin ✅
42. Fossils are studied in: Paleontology ✅
43. A group of similar organisms that can interbreed is called: Species ✅
44. The universal solvent is: Water ✅
45. The largest organ in the human body: Skin ✅
46. The pH of pure water is: 7 ✅
47. Blood type with no antigens: O ✅
48. Largest gland in the body: Liver ✅
49. Number of bones in an adult human body: 206 ✅
50. Unit of heredity: Gene ✅