'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
C.
repletion of vision pigment in rods
Two types of photoreceptor cells are present in retina, ie, rods and cones.
(i) Rods : These cells are active in dark rhodopsin, a vision pigment is present in rods. In strong light, rhodopsin is bleached due to splitting of its two components, ie, scotopsin and retinal.
(ii) Cones : These cells are active in strong light. Iodopsin a pigment is present in cones. These cells produce hare coloured image in bright light.
Which of the following is important for muscle contraction and nerve impulse transmission?
Ca2+ ions
Ca2+ and Mg2+ ions
Mg2+ ions
Fe2+ ions
Which cranial nerve has the highest number of branches?
Facial nerve
Trigeminal
Vagus nerve
None of these
The junction between the axon of one neuron and the dendrite of the next is called
Junction point
A synapse
A joint
Constant bridge
If the threshold for hearing increasing 1000 times, the hearing loss is
40 decibels
50 decibels
60 decibels
None of these
Sympathetic nervous system induces
Heartbeat
Secretion of digestive juice
Secretion of saliva
All of the above
In parasympathetic nervous system, which of the following is released?
Epinephrine
Norepinephrine
Serotonin
Acetylcholine
