KEGN ANDARGE W/G MEMORIAL SCHOOL

SECOND SEMITER GRADE 12 BIOLOGY EXAM ON UNIT 5

NAME ____________________________SEC________

1. What is the function of the cornea?

a) To focus light on the retina b) To produce aqueous humor
c) To control the size of the pupil d) To detect color
2. Which layer of the eye contains photoreceptor cells (rods and cones)?
a) Sclera b) Choroid c) Retina d) Cornea
3. In bright light, what happens to the radial muscles of the iris?
a) Contract b) Relax c) Disintegrate d) Expand
4. What condition results from a lack of vitamin A?
a) Color blindness b) Night blindness c) Astigmatism d) Glaucoma
5. How is short-sightedness (myopia) corrected?
a) Convex lenses b) Concave lenses c) Cylindrical lenses d) Bifocal lenses
6. Which part of the ear is responsible for balancing?
a) Cochlea b) Semi-circular canals c) Ossicles d) Tympanic membrane
7. What is the function of the Eustachian tube?
a) To amplify sound b) To equalize air pressure c) To produce earwax d) To detect vibrations
8. Which bone in the middle ear is connected to the oval window?
a) Malleus b) Incus c) Stapes d) Cochlea
9. What causes permanent deafness?
a) Earwax buildup b) Damage to the auditory nerve c) Temporary mucus blockage d) Loud noise
10. Where are the sensory hair cells for hearing located?
a) Pinna b) Tympanic membrane c) Cochlea d) Eustachian tube
11. Which taste sensation was recently discovered as the fifth basic taste?
a) Sweet b) Umami c) Bitter d) Sour
12. Why does food taste bland when you have a cold?
a) Taste buds are damaged b) Smell receptors are blocked by mucus
c) Saliva production stops d) Tongue swells
13. Which receptors detect chemicals in gaseous form?
a) Olfactory epithelial cells b) Taste buds c) Thermoreceptors d) Nociceptors
14. Where are taste buds predominantly located?
a) On the tongue only b) All over the tongue and throat
c) Only on the tip of the tongue d) In the nasal cavity
15. Which taste receptor is sensitive to savory flavors like meat and cheese?
a) Sweet b) Umami c) Bitter d) Salty
16. Which skin layer contains melanocytes?
a) Hypodermis b) Dermis c) Epidermis d) Subcutaneous layer
17. What is the function of Meissner’s corpuscles?
a) Detect pressure b) Detect pain c) Detect touch d) Detect temperature
18. Which part of the skin regulates body temperature?
a) Sweat glands b) Oil glands c) Hair follicles d) Melanocytes
19. What is the thickest layer of the skin?
a) Epidermis b) Dermis c) Hypodermis d) Stratum corneum
20. Which receptor detects pain?
a) Pacinian corpuscles b) Thermoreceptors c) Nociceptors d) Meissner’s corpuscles
21. Which hormone regulates metabolic rate?
a) Insulin b) Thyroxine c) Adrenaline d) Calcitonin
22. What causes goiter?
a) Excess thyroxine b) Iodine deficiency c) Overactive pituitary gland d) Lack of parathyroid
23. Which gland is both endocrine and exocrine?
a) Thyroid b) Pancreas c) Adrenal d) Pituitary

24. What is the function of insulin?

a) Increase blood glucose b) Decrease blood glucose
c) Stimulate glycogen breakdown d) Promote calcium absorption
25. Which hormone is responsible for the "fight or flight" response?
a) Oxytocin b) Adrenaline c) Prolactin d) Melatonin
26. What triggers ovulation in females?
a) FSH b) LH c) Progesterone d) Estrogen
27. Which hormone thickens the uterine lining?
a) Estrogen b) Progesterone c) FSH d) Testosterone
28. What is the role of testosterone in males?
a) Stimulates sperm production b) Deepens voice c) Promotes muscle growth d) All
29. What happens if FSH is insufficient in males?
a) Infertility b) Overproduction of sperm c) Increased testosterone d) No effect
30. Which hormone is responsible for milk production?
a) Oxytocin b) Prolactin c) Estrogen d) Progesterone
31. What is the role of the suspensory ligament in the eye?
a) Adjusts lens shape for near vision b) Produces vitreous humor
c) Protects the cornea d) Detects light intensity
32. Which part of the retina has the highest concentration of cones?
a) Blind spot b) Fovea c Optic nerve d) Choroid
33. What is astigmatism caused by?
a) Irregular cornea shape b) Weak ciliary muscles
c) Short eyeball d) Detached retina
34. Which gland is called the "master gland"?
a) Thyroid b) Pituitary c) Adrenal d) Pancreas

35. What is the function of antidiuretic hormone (ADH)?

 a) Increases urine output b) Decreases water reabsorption
c) Promotes water reabsorption d) Stimulates milk production
36. What causes cretinism?
a) Excess growth hormone b) Lack of thyroxine in children
c) Overproduction of insulin d) Calcium deficiency
37. Which condition results from overproduction of GH in adults?
a) Dwarfism b) Gigantism c) Acromegaly d) Goiter
38. What is a symptom of Type 1 diabetes?
a) Obesity b) Insulin resistance c) High blood glucose d) All of the above
39. Which hormone deficiency causes tetany?
a) Parathyroid hormone b) Calcitonin c) Thyroxine d) Adrenaline
40. What is menopause?
a) Start of menstruation b) Termination of menstrual cycles
c) Ovulation phase d) Fertilization process
41. Why does the brain perceive images as upright even though the retina receives inverted images?
a) The lens flips the image b) The brain interprets the inversion
c) The cornea corrects the image d) The optic nerve reverses signals
42. How does adrenalin prepare the body for danger?
a) Slows heart rate b) Dilates pupils
c) Reduces blood glucose d) All of the above
43. Why is iodine added to salt in some regions?
a) To prevent goiter b) To enhance taste c) To reduce blood pressure d) To cure diabetes

44. What happens if the corpus luteum degenerates?

a) Progesterone drops, causing menstruation b) Estrogen levels rise
c) FSH production increases d) Ovulation stops permanently
45. How does the skin protect against pathogens?
a) Produces antibodies b) Acts as a physical barrier c) Releases hormones d) Filters blood
46. If the ciliary muscles are paralyzed, what vision problem occurs?
a) Inability to focus on near objects b) Total blindness c) Color blindness d) Night blindness
47. What would happen if the oval window is damaged?
a) Balance loss b) Hearing impairment c) Reduced smell d) No effect
48. Why do rods work better in dim light than cones?
a) They contain vitamin A b) They are concentrated in the fovea
c) They detect color d) They are inactive in darkness
49. How does aldosterone affect blood pressure?
a) Increases sodium retention b) Decreases potassium levels
c) Dilates blood vessels d) All of the above
50. What is the role of the hypothalamus in hormone regulation?
a) Produces growth hormone b) Controls pituitary gland secretions
c) Directly releases insulin d) Stores thyroxine
51. What is the primary function of the nervous system?
 a) Digestion b) Rapid communication and coordination c) Hormone secretion d) Blood circulation
52. Which part of the neuron receives nerve signals?
a) Axon b) Myelin sheath c) Dendrites d) End brush
53. What is the role of the myelin sheath?
a) Produces neurotransmitters b) Insulates and speeds up nerve signal transmission
c) Stores energy for the neuron d) Initiates reflex actions
54. What is the microscopic gap between two neurons called?
a) Synapse b) Axon terminal c) Dendritic gap d) Nerve junction
55. Which type of neuron carries impulses from sense organs to the CNS?
a) Motor neuron b) Sensory neuron c) Interneuron d) Relay neuron
56. What is the function of neurotransmitters?
a) To provide energy to neurons b) To carry impulses across synapses
c) To produce myelin sheath d) To protect the brain
57. Which part of the brain controls higher-level thinking and memory?
a) Cerebellum b) Medulla c) Cerebrum d) Hypothalamus
58. What is the role of the hypothalamus?
a) Controls heartbeat b) Regulates body temperature and emotions
c) Coordinates muscle movement d) Processes visual information
59. Which part of the brain maintains body balance?
a) Thalamus b) Cerebellum c) Medulla oblongata d) Midbrain
60. What protects the brain from physical shocks?
a) Cranium only b) Meninges and cerebrospinal fluid c) Myelin sheath d) Vertebral column
61. Which part of the nervous system controls reflex actions like sneezing?
a) Cerebrum b) Spinal cord c) Peripheral nerves d) Hypothalamus
62. What is the direction of nerve impulse transmission across a synapse?
a) Dendrite → Axon b) Axon → Dendrite
c) Cell body → Myelin sheath d) End brush → Synapse
63. What is the white matter in the spinal cord primarily composed of?
a) Cell bodies b) Synapses c) Axons d) Dendrites
64. Which of the following is an example of a reflex action?
a) Solving a math problem b) Blinking when dust enters the eye
c) Writing a letter d) Speaking
65. What is the neural pathway of a reflex action called?
a) Nerve tract b) Reflex arc c) Synaptic cleft d) Axon pathway
66. Which root of the spinal cord carries sensory impulses into the spinal cord?
a) Ventral root b) Dorsal root c) Medullary root d) Cranial root
67. What is a conditioned reflex?
a) An inborn automatic response b) A learned response through experience
c) A hormonal reaction d) A voluntary muscle movement
68. Which part of the brain controls involuntary actions like breathing?
a) Cerebrum b) Medulla oblongata c) Thalamus d) Cerebellum
69. How many pairs of cranial nerves are there in humans?
 a) 10 b) 12 c) 31 d) 24
70. Which neurotransmitter is associated with pleasure and addiction?
a) Insulin b) Dopamine c) Adrenaline d) Melatonin
71. What is drug abuse?
a) Using prescribed drugs correctly b) Excessive and harmful use of drugs
c) Avoiding all drugs d) Using drugs only for medical purposes
72. Which of the following is a stimulant?
a) Alcohol b) Cannabis c) Caffeine d) Heroin
73. What is the addictive substance in cigarette smoke?
a) Tar b) Nicotine c) Carbon monoxide d) Cathinone
74. Which drug is classified as a hallucinogen?
a) Cocaine b) LSD c) Alcohol d) Paracetamol
75. What is a common effect of depressant drugs?
a) Increased alertness b) Slowed nervous system activity
c) Enhanced memory d) Reduced pain sensitivity
76. Which organ is most affected by excessive alcohol consumption?
a) Heart b) Liver c) Lungs d) Kidneys
77. What is the main psychoactive compound in khat?
a) Nicotine b) Cathinone c) THC d) Cocaine
78. Which drug is derived from the opium plant?
a) LSD b) Heroin c) Cannabis d) Caffeine
79. What is a withdrawal symptom?
a) Enhanced physical performance b) Symptoms when stopping drug use
c) Increased appetite d) Improved memory
80. Which of the following is an illegal drug in Ethiopia?
a) Coffee b) Khat c) Cannabis d) Tea
81. What is binge drinking?
a) Drinking small amounts frequently b) Consuming large amounts of alcohol quickly
c) Avoiding alcohol completely d) Drinking only on special occasions
82. Which drug is medically used as a painkiller but also abused?
a) Caffeine b) Heroin c) Nicotine d) Alcohol
83. What is a carcinogen?
a) A cancer-causing chemical b) A brain stimulant
c) A type of neurotransmitter d) A pain-relieving drug
84. Which of the following is a social effect of drug abuse?
a) Improved family relationships b) Increased productivity
c) Crime and violence d) Better academic performance
85. What is the primary effect of hallucinogens?
a) Slowed heart rate b) Altered perception of reality
c) Increased energy d) Pain relief
86. Which drug can cause sudden death even on first use?
a) Caffeine b) Cocaine c) Paracetamol d) Khat
87. What is the main risk of sharing needles in drug use?
a) Lung cancer b) HIV/AIDS transmission
c) Improved immunity d) Faster drug effects
88. Which part of the brain is most affected by long-term drug use?
a) Cerebellum b) Medulla
c) Prefrontal cortex (decision-making) d) Thalamus
89. What is insomnia?
a) Excessive sleep b) Inability to sleep
c) Increased appetite d) Memory loss
90. Which of the following is a legal drug in Ethiopia?
a) Cocaine b) Heroin c) Alcohol d) LSD
91. What is the effect of sedatives on the nervous system?
a) Speed up nerve impulses b) Slow down nerve activity
c) Enhance memory d) Increase pain sensitivity
92. Which drug is associated with "paranoia" and "depression" after use?
a) Cannabis b) Cocaine c) Alcohol d) Aspirin
93. What is a common health effect of smoking?
a) Improved lung function b) Coronary heart disease
c) Stronger bones d) Better digestion
94. Which drug is known to cause "cottonmouth" (dry mouth)?
a) Alcohol b) Cannabis c) Heroin d) Nicotine
95. What is the term for inhaling secondhand smoke?
a) Active smoking b) Passive smoking c) Vaping d) Chewing
96. Which drug is commonly found in beverages like coffee and tea?
a) THC b) Caffeine c) Nicotine d) Cocaine
97. What is the primary reason people use drugs recreationally?
a) To cure diseases b) For pleasure or relaxation
c) To improve memory d) To reduce weight
98. Which drug is most likely to cause hallucinations?
a) Alcohol b) LSD c) Nicotine d) Paracetamol
99. What is a long-term effect of heroin use?
a) Increased appetite b) Loss of pain sensation
c) Improved reflexes d) Better vision
100. Which of the following is NOT a withdrawal symptom?
a) Headache b) Craving for the drug
c) Improved concentration d) Sweating