ONE-EIGHTH STAGE 2026
Prempeh College: 66 points
West Africa SHS: 30 points
Kumasi Girls’ SHS: 19 points
Keta SHTS: 56 points
Kadjebi-Asato SHS: 28 points
Anum Presby SHS: 19 points
Ghana National College: 38 points
St. Monica’s SHS: 22 points
Presby SHS, Suhum: 16 points
ROUND 5 - RIDDLE
RIDDLE
I am an ordered arrangement of specialized cells.
I was discovered by an Italian anatomist in 1851.
I am located in the cochlea of the human ear.
I am of significant clinical importance due to my central role in the auditory system.
My primary function is to convert the mechanical energy of sound vibrations into electrochemical signals that the brain can interpret.
ANSWER: Organ of Corti
EXPLANATION:
The organ of Corti, described by Alfonso Corti in 1851, lies on the basilar membrane inside the cochlea.
Its hair cells turn sound vibrations into nerve impulses carried by the auditory nerve to the brain.
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PRACTICE QUESTIONS
1. RIDDLE:
We are receptor cells.
We are found in the inner ear.
We have tufts of stereocilia on top.
We are bent when the membrane beneath us vibrates.
We turn vibration into nerve impulses.
We are the sensory cells of the organ of Corti.
Who am I?
ANSWER: HAIR CELLS
EXPLANATION:
Hair cells are the sensory cells of the organ of Corti.
2. RIDDLE:
I am a membrane.
I am found in the cochlea.
The organ of Corti sits on me.
I am narrow and stiff near the base of the cochlea.
I am wide and floppy near the tip.
Different parts of me vibrate for different pitches.
Who am I?
ANSWER: BASILAR MEMBRANE
EXPLANATION:
The basilar membrane supports the organ of Corti and sorts pitch.
3. RIDDLE:
I am a membrane.
I am found in the cochlea.
I lie above the hair cells.
I am jelly-like.
The tips of the hair cells touch me.
Movement against me bends the hairs.
Who am I?
ANSWER: TECTORIAL MEMBRANE
EXPLANATION:
The tectorial membrane bends the hair cells' stereocilia.
4. RIDDLE:
I am part of the nervous system.
I am the eighth of the paired cranial fibres from the brain.
I have a branch for balance.
My other branch comes from the cochlea.
I carry impulses from the hair cells to the brain.
I carry the sense of hearing to the brain.
Who am I?
ANSWER: AUDITORY NERVE
EXPLANATION:
The auditory (vestibulocochlear) nerve carries sound impulses to the brain.
5. RIDDLE:
I am a fluid.
I am found in the inner ear.
I fill the membranous canals.
I am rich in potassium ions.
I bathe the tops of the hair cells.
Perilymph surrounds the canals that I fill.
Who am I?
ANSWER: ENDOLYMPH
EXPLANATION:
Endolymph fills the scala media.
6. RIDDLE:
I am part of the inner ear.
I am coiled like a snail shell.
I have three fluid-filled canals.
I contain the organ of Corti.
I turn sound into nerve impulses.
I am the organ of hearing.
Who am I?
ANSWER: COCHLEA
EXPLANATION:
The cochlea is the snail-shaped organ of hearing.
7. RIDDLE:
I am an opening.
I am covered by a membrane.
I lead into the inner ear.
The stapes presses on me.
I pass vibrations to the fluid of the cochlea.
A second, round opening lies below me.
Who am I?
ANSWER: OVAL WINDOW
EXPLANATION:
The stapes pushes on the oval window.
8. RIDDLE:
I am a bone.
I am the smallest bone in the body.
I am in the middle ear.
I am the last of the three ossicles.
My footplate fits into the oval window.
I am named for my stirrup shape.
Who am I?
ANSWER: STAPES
EXPLANATION:
The stapes passes vibrations to the oval window.
9. RIDDLE:
I am a narrow passage.
I join the middle ear to the throat.
I open when you swallow or yawn.
I equalise the air pressure on both sides of the eardrum.
My opening makes the ears "pop" in an aeroplane.
I am named after an Italian anatomist.
Who am I?
ANSWER: EUSTACHIAN TUBE
EXPLANATION:
The Eustachian tube equalises middle ear pressure.