Human ear ossicles are

• incus and stapes

• stapes

• incus, malleus and stapes

• incus and malleus

'Adaptation' of eyes in dark is due to

• depletionof vision pigment in rods

• depletion of vision pigment in cones

• repletion of vision pigment in rods

• repletion of vision pigment in cones

Which of the following is important for muscle contraction and nerve impulse transmission?

• Ca²⁺ ions

• Ca²⁺ and Mg²⁺ ions

• Mg²⁺ ions

• Fe²⁺ ions

In parasympathetic nervous system, which of the following is released?

• Epinephrine

• Norepinephrine

• Serotonin

• Acetylcholine

The velocity of conduction of nerve impulse in frog is

• 300 m/s

• same as of electricity

• faster than sound

• 30 m/s

206.

Tree of life is

• arbor vitae

• pons Varolii

• organ of Corti

• diencephalon

Eustachian canal connects

• middle ear with external ear

• middle ear with internal ear

• external ear with internal ear

• pharynx with middle ear

From outer to inside the sequence of three bones present in the middle ear of mammals is

• malleus, stapes and incus

• stapes, malleus and incus

• malleus, incus and stapes

• incus, malleus and stapes

The cavity of diencephalon is known as

• I ventricle

• II ventricle

• III ventricle

• iter

Aqueous and vitreous humour are divided by

• lens

• iris

• retina

• optic nerve