Biology - Study Mode

[#751] The story of vitamins dates back to
Correct Answer

(D) 18th century

Explanation

Solution: The story of vitamins dates back to 18th century.

[#752] Study of nose and alfactory organs is called
Correct Answer

(B) Rhinology

Explanation

Solution: Study of nose and alfactory organs is called Rhinology.

[#753] The size of the pupil is controlled by the
Correct Answer

(B) Iris

Explanation

Solution: The size of the pupil is controlled by the activities of two muscles: the circumferential sphincter muscle found in the margin of the iris, innervated by the parasympathetic nervous system: and the iris dilator muscle, running radially from the iris root to the peripheral border of the sphincter.

[#754] Damage to hearing is caused by sounds which exceed
Correct Answer

(D) 120 decibles

Explanation

Solution: Noise is a level of sound beyond the capacity of ears. Normal level of sound for conversation is 60 decibels and lawn mower is 90 decibels that can not harm the ears but very high levels of noise (at or above 120 decibels) exposure can leads to hearing loss. Noise-induced hearing loss is irreversible, the main form of treatment is prevention.

[#755] Human beings hearing range is ________
Correct Answer

(D) 20 to 20,000 Hz

Explanation

Solution: Human beings hearing range is 20 to 20,000 Hz.