50 JAMB, WAEC & NABTEB Biology Questions on The Mammalian Ear (Theory and Objective) With Answers

This set of 50 questions covers the structure and function of the mammalian ear, including the outer, middle, and inner ear, the mechanism of hearing, maintenance of balance, and care of the ear. The questions are a blend of theory (structured essay-type) and objective (multiple-choice) formats, designed to WAEC and JAMB standards. Use them to master the auditory system and prepare effectively for your examinations.

Section A: Theory Questions (1–15)

1. Describe the structure of the outer ear in mammals and state one function each of its components.
2. Name the three ear ossicles in the middle ear in their correct sequence from the tympanic membrane inward.
3. Explain how the Eustachian tube helps maintain proper hearing function.
4. Describe the mechanism of hearing in mammals, from the entry of sound waves to interpretation by the brain.
5. State two ways by which the ear ossicles aid the process of hearing.
6. Explain the role of the cochlea and the organ of Corti in hearing.
7. How does the ear help in the maintenance of body balance? Include the roles of the semicircular canals, ampulla, and endolymph.
8. State three causes of deafness in humans and explain how each leads to hearing loss.
9. State five ways of caring for the ear.
10. Differentiate between the functions of the cochlea and the semicircular canals.
11. Explain why a person spinning rapidly for some time and then stopping may lose balance temporarily.
12. State one function each of the following structures found in the ear: (i) pinna (ii) tympanic membrane (iii) malleus (iv) stapes (v) organ of Corti.
13. Describe the structure of the internal ear, naming the main sensory structures and the fluids they contain.
14. What is the significance of the round window and oval window in the transmission of sound?
15. Explain the effect of loud noise on hearing and suggest two preventive measures.

JAMB, WAEC & NABTEB Biology Questions on The Mammalian Ear

16. The mammalian ear is responsible for the functions of
    A. sight and balance
    B. hearing and balance
    C. hearing and speech
    D. taste and balance
17. The ear is divided into how many main regions?
    A. Two
    B. Three
    C. Four
    D. Five
18. The three regions of the ear are the external ear, middle ear and the
    A. cochlea
    B. labyrinth (inner ear)
    C. semicircular canals
    D. Eustachian tube
19. The pinna is made of soft cartilage covered by skin and is only found in
    A. all vertebrates
    B. birds
    C. mammals
    D. amphibians
20. One major function of the pinna is to
    A. produce wax to trap insects
    B. equalize air pressure
    C. collect and direct sound waves into the auditory meatus
    D. amplify sound waves across the oval window
21. The external auditory canal contains glands that produce
    A. mucus
    B. wax
    C. endolymph
    D. perilymph
22. The fine hairs in the ear tube serve to
    A. amplify sound
    B. maintain balance
    C. prevent entry of tiny insects, dust, and germs
    D. equalize air pressure
23. The tympanic membrane (ear drum) separates the
    A. middle ear from the inner ear
    B. outer ear from the middle ear
    C. cochlea from the semicircular canals
    D. oval window from the round window
24. The middle ear is also known as the
    A. labyrinth
    B. tympanic cavity
    C. cochlea
    D. ampulla
25. The ear ossicle that is attached to the tympanic membrane is the
    A. stapes
    B. incus
    C. malleus (hammer)
    D. anvil
26. The smallest bone in the human body is the
    A. malleus
    B. incus
    C. stapes (stirrup)
    D. cochlea
27. The stapes fits into the
    A. round window
    B. Eustachian tube
    C. tympanic membrane
    D. oval window
28. The Eustachian tube connects the middle ear to the
    A. cochlea
    B. back of the pharynx
    C. semicircular canals
    D. external auditory canal
29. The main function of the Eustachian tube is to
    A. transmit sound to the brain
    B. equalize air pressure on both sides of the ear drum
    C. produce endolymph
    D. detect the direction of sound
30. The inner ear contains a complex bony passage filled with fluid called
    A. endolymph
    B. perilymph
    C. wax
    D. mucus
31. The membranous labyrinth is filled with
    A. perilymph
    B. air
    C. endolymph
    D. plasma
32. The organ for hearing located in the inner ear is the
    A. semicircular canals
    B. utriculus
    C. cochlea
    D. sacculus
33. The structures concerned with balance in the inner ear are the
    A. cochlea and organ of Corti
    B. tympanic membrane and ossicles
    C. semicircular canals, utriculus, and sacculus
    D. pinna and auditory canal
34. The swollen part at the base of each semicircular canal containing sensitive cells is called the
    A. ampulla
    B. utriculus
    C. sacculus
    D. cochlea
35. The sensitive cells arranged on the lower membrane of the middle chamber of the cochlea form the
    A. organ of Corti
    B. Eustachian tube
    C. ampulla
    D. round window
36. Sound waves entering the outer ear first reach the
    A. oval window
    B. cochlea
    C. tympanic membrane
    D. organ of Corti
37. The vibration of the auditory ossicles helps to
    A. equalize pressure
    B. amplify the sound
    C. maintain balance
    D. produce wax
38. The fluid in the cochlea that vibrates upon receiving waves from the oval window is the
    A. endolymph
    B. blood
    C. perilymph
    D. mucus
39. Vibrations in the cochlea are transmitted across the
    A. semicircular canals
    B. Eustachian tube
    C. organ of Corti (sensory nerve cells)
    D. malleus
40. The auditory nerve transmits impulses from the ear to the
    A. cerebellum
    B. auditory lobes of the brain
    C. medulla oblongata
    D. spinal cord
41. Head movement in any direction affects the fluid (endolymph) in the
    A. cochlea
    B. corresponding semicircular canals
    C. Eustachian tube
    D. outer ear
42. The semicircular canals are arranged at
    A. acute angles to each other
    B. right angles to each other
    C. 45-degree angles to each other
    D. random orientations
43. A boy spins round several times and stops. He loses balance as he attempts to walk. The most likely explanation for this is
    A. high pressure in the ear fluid
    B. too much air pressure in the middle ear
    C. continuous movement of the fluid in the inner ear
    D. rotation of the semi-circular canals
44. Deafness is defined as the
    A. inability to see
    B. inability to balance
    C. inability to hear
    D. inability to speak
45. Which of the following is a cause of deafness?
    A. Damage to the pinna
    B. Hardening of stapes and fusing with the oval window
    C. Overproduction of endolymph
    D. Enlargement of the Eustachian tube
46. Blocking of the ear canal by wax can lead to
    A. loss of balance only
    B. deafness
    C. vertigo only
    D. increased hearing sensitivity
47. Which of the following is NOT a recommended way of caring for the ear?
    A. Cleaning the ear regularly with cotton wool
    B. Avoiding the use of sharp objects in the ear
    C. Using sharp objects to remove ear wax
    D. Consulting a doctor for ear problems
48. A person working in a high-noise environment should
    A. clean the ears more frequently with sharp objects
    B. use protective ear muffs
    C. expose ears to louder noise for adaptation
    D. ignore the noise level
49. Which of the following statements is correct about the mammalian ear?
    A. The round window is found in the outer ear
    B. The stapes is the largest bone in the body
    C. The organ of Corti contains sensory cells for hearing
    D. The Eustachian tube connects the outer ear to the brain
50. The membrane that connects the middle ear with the inner ear besides the oval window is the
    A. tympanic membrane
    B. round window
    C. pinna
    D. basilar membrane

Answer Key (Theory Guidelines)

1. Outer ear: Pinna collects/directs sound waves. External auditory canal: passage with wax and hairs. Tympanic membrane: transmits vibrations to middle ear.
2. Malleus (hammer), Incus (anvil), Stapes (stirrup).
3. Eustachian tube equalizes air pressure on both sides of the eardrum, allowing proper vibration.
4. Sound waves → auditory canal → tympanic membrane vibrates → ossicles vibrate/amplify → oval window vibrates → perilymph in cochlea vibrates → endolymph vibrates → organ of Corti stimulated → impulses sent via auditory nerve to brain for interpretation.
5. Ossicles transmit vibrations from tympanic membrane to oval window; they magnify pressure on the oval window.
6. Cochlea houses the organ of Corti. The organ of Corti contains sensory hair cells that convert vibrations into nerve impulses for hearing.
7. Head movement causes endolymph in semicircular canals to move. This stimulates sensory cells in the ampulla, generating impulses via auditory nerve to brain, which then signals body muscles for balance.
8. Damage to tympanic membrane (prevents vibration), stapes hardening fusing with oval window (blocks sound transmission), blocking of ear canal by wax (prevents sound reaching eardrum).
9. Clean ear with cotton wool; avoid sharp objects; avoid blows to ear; use ear muffs in noisy areas; avoid prolonged loud noise; consult doctor for ear problems (any five).
10. Cochlea is for hearing; semicircular canals are for balance.
11. The continuous movement of fluid (endolymph) in the semicircular canals causes impulses to continue being sent to the brain, creating a sensation of imbalance.
12. (i) Pinna: collects/directs sound. (ii) Tympanic membrane: transmits vibrations. (iii) Malleus: receives vibrations from tympanic membrane. (iv) Stapes: fits into oval window, transmits vibrations to inner ear. (v) Organ of Corti: contains sensory cells for hearing.
13. Inner ear contains bony labyrinth (perilymph) and membranous labyrinth (endolymph). Sensory structures: cochlea (hearing) and semicircular canals/utriculus/sacculus (balance).
14. Oval window receives vibrations from stapes and passes them to inner ear fluids. Round window relieves pressure as the fluid in the cochlea moves.
15. Loud noise damages sensory cells in cochlea, leading to deafness. Prevention: use ear muffs, avoid prolonged exposure to loud noise.

Answer Key (Objective)

16. B
17. B
18. B
19. C
20. C
21. B
22. C
23. B
24. B
25. C
26. C
27. D
28. B
29. B
30. B
31. C
32. C
33. C
34. A
35. A
36. C
37. B
38. C
39. C
40. B
41. B
42. B
43. C
44. C
45. B
46. B
47. C
48. B
49. C
50. B