Answer to Question 1
C
The tympanic membrane is the boundary between the outer ear and middle ear. The three bones (ossicles) of the middle ear are the malleus (hammer), incus (anvil), and stapes (stirrup). The malleus is attached to the tympanic membrane; the incus joins the malleus to the stapes, which rests on the oval window. The vibration created by sound waves passes through the outer ear canal to the tympanic membrane and then to these three bones. The eustachian tube opens into the pharynx from the middle ear to equalize pressure on both sides of the eardrum.
Answer to Question 2
B
In the inner ear, the nerves respond to different sounds and initiate neural responses that are sent along the auditory nerve (cranial nerve VIII) to the brain. The inner ear also maintains equilibrium.
Structure of a nucleosome
Structure of a b turn
The double-helix structure of DNA.
C1qrs. A schematic of C1 showing structure and C1q, r, and s.
Structure of a nail
Structure and function of the gills of a bony fish.