Q1. What is the pH range of human blood?
a) 6.8-7.0
b) 7.3-7.5
c) 7.35-7.45
d) 8.0-8.5
Answer: c) 7.35-7.45 (Slightly alkaline)
Q2. Which organ produces bile?
a) Pancreas
b) Gallbladder
c) Liver
d) Stomach
Answer: c) Liver (Gallbladder stores bile)
Q3. Smallest bone in the human body is located in the:
a) Hand
b) Ear
c) Foot
d) Nose
Answer: b) Ear (Stapes in middle ear)
Q4. Which vitamin is synthesized by gut bacteria?
a) Vitamin A
b) Vitamin B12
c) Vitamin C
d) Vitamin D
Answer: b) Vitamin B12 (Essential for RBC formation)
Q5. Normal human body temperature is:
a) 98.4°F (36.9°C)
b) 98.6°F (37°C)
c) 99.0°F (37.2°C)
d) 100.4°F (38°C)
Answer: b) 98.6°F (37°C) (Can vary slightly)
Q9. The pigment responsible for photosynthesis is:
a) Chlorophyll
b) Carotene
c) Xanthophyll
d) Phycobilin
Answer: a) Chlorophyll (Absorbs blue & red light)
Q10. Which plant hormone promotes cell division?
a) Auxin
b) Gibberellin
c) Cytokinin
d) Abscisic acid
Answer: c) Cytokinin (Works with auxin for growth)
Q11. The edible part of a potato is a modified:
a) Root
b) Stem
c) Leaf
d) Flower
Answer: b) Stem (Tuber stores food underground)
Q12. Which disease is caused by a deficiency of vitamin C?
a) Beriberi
b) Scurvy
c) Rickets
d) Pellagra
Answer: b) Scurvy (Bleeding gums, poor wound healing)
Q13. Dengue fever is transmitted by:
a) Anopheles mosquito
b) Aedes mosquito
c) Culex mosquito
d) Housefly
Answer: b) Aedes mosquito (Day-biting, striped legs)
Q14. The father of genetics is:
a) Charles Darwin
b) Gregor Mendel
c) Hugo de Vries
d) Thomas Hunt Morgan
Answer: b) Gregor Mendel (Pea plant experiments, 1865)
Q15. Human males have which sex chromosomes?
a) XX
b) XY
c) YY
d) XO
Answer: b) XY (Females: XX)
Q16. The ozone layer protects Earth from:
a) UV radiation
b) Infrared rays
c) X-rays
d) Cosmic rays
Answer: a) UV radiation (Prevents skin cancer)
Q17. Most abundant greenhouse gas is:
a) Methane
b) Carbon dioxide
c) Water vapor
d) Nitrous oxide
Answer: c) Water vapor (Natural greenhouse effect)
Q18. Which part of the brain regulates body temperature?
a) Cerebrum
b) Cerebellum
c) Hypothalamus
d) Medulla oblongata
Answer: c) Hypothalamus (Also controls hunger and thirst)
Q19. Total number of bones in an adult human body is:
a) 206
b) 260
c) 300
d) 150
Answer: a) 206 (Babies have about 300 bones that fuse together)
Q20. Which vitamin helps in blood clotting?
a) Vitamin A
b) Vitamin B12
c) Vitamin C
d) Vitamin K
Answer: d) Vitamin K (Essential for prothrombin synthesis)
Q21. The largest artery in the human body is:
a) Pulmonary artery
b) Aorta
c) Coronary artery
d) Renal artery
Answer: b) Aorta (Carries oxygenated blood from heart to body)
Q22. Which gland is both endocrine and exocrine?
a) Thyroid
b) Pancreas
c) Pituitary
d) Adrenal
Answer: b) Pancreas (Endocrine: insulin; Exocrine: digestive enzymes)
Q23. The process by which plants lose water is called:
a) Photosynthesis
b) Transpiration
c) Respiration
d) Guttation
Answer: b) Transpiration (Occurs mainly through stomata)
Q24. Which plant hormone is responsible for fruit ripening?
a) Auxin
b) Gibberellin
c) Ethylene
d) Cytokinin
Answer: c) Ethylene (Gas hormone that accelerates ripening)
Q25. The study of pollen is called:
a) Pomology
b) Palynology
c) Phycology
d) Mycology
Answer: b) Palynology (Important for forensic and archaeological studies)
Q26. Which disease is caused by deficiency of Vitamin D?
a) Scurvy
b) Rickets
c) Beriberi
d) Pellagra
Answer: b) Rickets (Softening and weakening of bones in children)
Q27. BCG vaccine is used to prevent:
a) Tuberculosis
b) Polio
c) Cholera
d) Typhoid
Answer: a) Tuberculosis (Bacillus Calmette-Guérin vaccine)
Q28. The theory of 'Natural Selection' was proposed by:
a) Gregor Mendel
b) Charles Darwin
c) Lamarck
d) Hugo de Vries
Answer: b) Charles Darwin (Published in "On the Origin of Species")
Q29. Down syndrome is caused by:
a) Extra chromosome 21
b) Missing X chromosome
c) Extra Y chromosome
d) Mutation in chromosome 5
Answer: a) Extra chromosome 21 (Trisomy 21)
Q30.The ozone layer is present in:
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
Answer: b) Stratosphere (Absorbs 97-99% of Sun's UV radiation)
Q31. The most abundant gas in Earth's atmosphere is:
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Argon
Answer: c) Nitrogen (78% of atmospheric composition)
Q32. Which part of the eye contains light-sensitive cells?
a) Cornea
b) Retina
c) Iris
d) Lens
Answer: b) Retina (Contains rods for dim light and cones for color vision)
Q33. The hormone responsible for regulating blood sugar levels is:
a) Adrenaline
b) Insulin
c) Thyroxine
d) Estrogen
Answer: b) Insulin (Secreted by pancreatic beta cells; deficiency causes diabetes)
Q34. Which blood cells are responsible for immune defense?
a) RBCs
b) Platelets
c) WBCs
d) Plasma
Answer: c) WBCs (Leukocytes fight infections; include lymphocytes and phagocytes)
Q35. The largest part of the human brain is:
a) Cerebellum
b) Cerebrum
c) Medulla oblongata
d) Hypothalamus
Answer: b) Cerebrum (Controls voluntary actions, intelligence, and memory)
Q36. Which organ produces urine?
a) Liver
b) Kidney
c) Pancreas
d) Gallbladder
Answer: b) Kidney (Nephrons filter blood to form urine)
Q37. Process by which plants make food is called:
a) Respiration
b) Transpiration
c) Photosynthesis
d) Fermentation
Answer: c) Photosynthesis (Occurs in chloroplasts using sunlight, CO₂, and water)
Q38. Which plant part anchors it to the soil?
a) Stem
b) Leaf
c) Root
d) Flower
Answer: c) Root (Also absorbs water and minerals from soil)
Q39. The male reproductive part of a flower is called:
a) Pistil
b) Stamen
c) Petal
d) Sepal
Answer: b) Stamen (Consists of anther and filament; produces pollen)
Q40. Which disease is caused by a virus?
a) Tuberculosis
b) Malaria
c) COVID-19
d) Cholera
Answer: c) COVID-19 (Caused by SARS-CoV-2; others are bacterial/protozoan)
Q41. Vaccines work by:
a) Killing pathogens directly
b) Stimulating antibody production
c) Reducing body temperature
d) Blocking nerve signals
Answer: b) Stimulating antibody production (Creates immune memory without causing disease)
Q42. The basic unit of heredity is:
a) Chromosome
b) Gene
c) Nucleotide
d) Protein
Answer: b) Gene (Segment of DNA coding for a specific trait)
Q43. Human somatic cells contain how many chromosomes?
a) 23
b) 46
c) 22
d) 44
Answer: b) 46 (23 pairs; gametes have 23 single chromosomes)
Q44. The primary source of energy in an ecosystem is:
a) Water
b) Soil
c) Sun
d) Air
Answer: c) Sun (Plants convert solar energy to chemical energy via photosynthesis)
Q45. Acid rain is caused by emissions of:
a) Oxygen and nitrogen
b) Sulfur dioxide and nitrogen oxides
c) Carbon monoxide and methane
d) Ozone and CFCs
Answer: b) Sulfur dioxide and nitrogen oxides (React with water to form acids)
Q46. Which organ produces insulin?
a) Liver
b) Pancreas
c) Kidney
d) Spleen
Answer: b) Pancreas (Beta cells in Islets of Langerhans produce insulin to regulate blood sugar)
Q47. The smallest blood vessels in the body are:
a) Arteries
b) Veins
c) Capillaries
d) Venules
Answer: c) Capillaries (Site of gas/nutrient exchange between blood and tissues)
Q48. Which part of the brain controls breathing rate?
a) Cerebrum
b) Cerebellum
c) Medulla oblongata
d) Hypothalamus
Answer: c) Medulla oblongata (Controls vital autonomic functions like breathing and heart rate)
Q49. The total number of cranial nerves in humans is:
a) 10
b) 12
c) 14
d) 16
Answer: b) 12 (Roman numbered I-XII, e.g., Optic nerve is II)
Q50. Which vitamin is crucial for calcium absorption?
a) Vitamin A
b) Vitamin B12
c) Vitamin C
d) Vitamin D
Answer: d) Vitamin D (Deficiency causes rickets in children and osteomalacia in adults)
Q51.Movement of plant parts toward light is called:
a) Geotropism
b) Phototropism
c) Hydrotropism
d) Thigmotropism
Answer: b) Phototropism (Auxin hormone mediates this response)
Q52. Which plant tissue transports water and minerals?
a) Phloem
b) Xylem
c) Cambium
d) Epidermis
Answer: b) Xylem (Composed of tracheids and vessels; transports upward)
Q53. Female reproductive part of a flower is called:
a) Stamen
b) Pistil
c) Petal
d) Sepal
Answer: b) Pistil (Consists of stigma, style, and ovary)
Q54. Which disease is caused by a deficiency of iodine?
a) Goiter
b) Scurvy
c) Beriberi
d) Pellagra
Answer: a) Goiter (Enlargement of thyroid gland; iodized salt prevents this)
Q55. Polio vaccine was developed by:
a) Louis Pasteur
b) Jonas Salk
c) Robert Koch
d) Alexander Fleming
Answer: b) Jonas Salk (Inactivated polio vaccine introduced in 1955)
Q56. The father of the 'Theory of Inheritance of Acquired Characteristics' is:
a) Charles Darwin
b) Gregor Mendel
c) Jean-Baptiste Lamarck
d) Hugo de Vries
Answer: c) Jean-Baptiste Lamarck (Proposed before Darwin; later disproven)
Q57. A human somatic cell contains how many autosomes?
a) 22
b) 23
c) 44
d) 46
Answer: c) 44 (22 pairs; plus 2 sex chromosomes = total 46)
Q58. The major greenhouse gas emitted from agricultural activities is:
a) Carbon dioxide
b) Methane
c) Nitrous oxide
d) Ozone
Answer: b) Methane (From livestock digestion and rice paddies)
Q59. The zone of the earth where life exists is called:
a) Atmosphere
b) Lithosphere
c) Biosphere
d) Hydrosphere
Answer: c) Biosphere (Includes all living organisms and their environment)
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