Question

In which process(es) are hair cells involved? a. balance in vertebrates and invertebrates b. hearing in mammals c. vision in animals with compound eyes d. heat sensing in pit vipers e. both a and b

Short answer

Hair cells are involved in the processes of balance in vertebrates and invertebrates, and hearing in mammals. Therefore, options a, b and e are correct.

Step-by-step solution

Elimination of irrelevant options

Start by ruling out the processes that you know do not involve hair cells. Vision in animals with compound eyes and heat sensing in pit vipers are not related to the function of hair cells. Therefore, option c) and d) can be safely eliminated from the list.

Identification of processes involving hair cells

Now, you have three remaining options: balance in vertebrates and invertebrates, hearing in mammals and both a and b. Hair cells are indeed involved in balance in vertebrates and invertebrates and hearing in mammals. That means options a), b) and e) are all correct.

Key concepts

Balance in Vertebrates

Balance in vertebrates, or biological equilibrium, is crucial for the survival and daily activities of these animals. It allows them to maintain their posture and orientation. Hair cells play an integral role in this process.
These specialized cells are found in the inner ear within the vestibular system, specifically in the semicircular canals and the otolith organs.
This system provides sensory information about motion, equilibrium, and spatial orientation. When the head moves, fluid inside the semicircular canals of the inner ear shifts. This movement displaces the hair cells. As a result, they send signals to the brain about the direction and speed of the movement. The otolith organs, another part of the vestibular system, detect linear accelerations and head tilts. Hair cells in these organs are topped with tiny crystals called otoliths. These crystals shift with motion, pulling on the hair cells and triggering a signal.

• Maintains balance and spatial orientation.
• Located in the inner ear's vestibular system.
• Involves the semicircular canals and otolith organs.
• Hair cell displacement sends signals to the brain.

Hearing in Mammals

Hair cells are vital for hearing in mammals. They are located within the cochlea in the inner ear.
The cochlea is a spiral-shaped organ that converts sound waves into electrical signals.
When sound waves enter the ear, they create vibrations in the ear drum, which are then amplified by the ossicles, the tiny bones in the middle ear, and transmitted to the cochlea. Inside the cochlea, hair cells are arranged in rows along the basilar membrane.
These cells have tiny hair-like projections known as stereocilia. When the cochlear fluids move due to sound wave energy, the stereocilia bend and create a mechanical-to-electrical signal conversion. This signal is then transmitted to the brain through auditory nerves. This complex mechanism allows mammals to perceive a wide range of sounds from the environment, playing an essential role in communication and awareness.

• Hair cells located in the cochlea of the inner ear.
• Sound waves cause vibrations to stimulate hair cells.
• Stereocilia on hair cells convert vibrations into electrical signals.
• Signals are sent to the brain for sound perception.

Sensory Reception

Sensory reception is an overarching concept where hair cells are integral in processes like balance and hearing. These cells are adept mechanoreceptors, meaning they sense physical changes and stimuli.
In both balance and hearing, hair cells translate mechanical movements into neural signals.
They contain specialized structures that can respond to fluid motion or vibrations in the surrounding environment, essential for detecting external stimuli. The ability of hair cells to convert mechanical stimuli into electrical signals and send them to the brain showcases their critical role in sensory reception.
This conversion is fundamental for processing sensory information, allowing organisms to interact with their environment effectively.

• Hair cells act as mechanoreceptors.
• Convert mechanical changes into neural signals.
• Vital for effective sensory processing and interpretation.
• Enable organisms to respond to external stimuli.