About 20% of the Human Population Has the Bacteria That

question 42

Multiple Choice

About 20% of the human population has the bacteria that causes childbed fever living on their skin, and yet death from it is very rare. Why?

• A) People are now resistant to the bacteria.
• B) The bacteria has evolved such that it never causes disease.
• C) With all the antibacterial soaps available, most humans don't come in contact with bacteria.
• D) The bacteria is only dangerous if it gets in the bloodstream and now it can be treated by antibiotics.
• E) Doctors now routinely wash their hands.
• "How do we know?"

---

Definitions:

Sound Waves

Vibrations that travel through a medium such as air, producing the sensation of sound.

Inner Ear

The innermost part of the ear, containing the cochlea, vestibule, and semicircular canals, responsible for hearing and balance.

Oval Window

A membrane-covered opening that leads from the middle ear to the vestibule of the inner ear, where sound vibrations are transmitted.

Cochlear Duct

A fluid-filled spiral tunnel in the inner ear and a key component of the cochlea, responsible for sound perception.