In mammals horizontal acceleration is detected by ?

Ans. is 'a' i.e., Utricle The utricle, along with the saccule, is one of the two otolith organs located in the veebrate inner ear. The utricle and the saccule are pas of the balancing apparatus (membranous labyrinth) located within the vestibule of the bony labyrinth (small oval chamber). These use small stones and a viscous fluid to stimulate hair cells to detect motion and orientation. The utricle detects linear accelerations and head-tilts in the horizontal plane.