Final answer:
The wide and floppy portion of the basilar membrane is located at the apex of the cochlea, and it is better suited to detect low-frequency sounds, while the base of the membrane responds best to high-frequency sounds.
Step-by-step explanation:
The subject of this question is the physiology of hearing, specifically focusing on how the basilar membrane within the cochlea of the inner ear responds to different sound frequencies. The place theory of pitch perception states that different areas of the basilar membrane are sensitive to different frequencies. The portion of the membrane is wide and floppy and is located at the apex of the cochlea and is better at responding to low-frequency sounds. In contrast, the base of the basilar membrane is thicker, tauter, and narrower, which allows it to respond best to high-frequency sounds.
Hair cells near the base of the basilar membrane are adapted to high-frequency sounds, while those near the apex are adapted for low-frequency sounds. When the cochlear fluid vibrates due to sound waves, hair cells sitting atop the basilar membrane are displaced, initiating the auditory signal's transmission to the brain for sound perception.