Stimulation of a muscle fibre by a motor neuron occurs at

  • the neuromuscular junction

  • the transverse tubules

  • the myofibril

  • the sacroplasmic reticulum

Na+/K+ pump is associated with

  • passive transport

  • active transport

  • osmosis

  • imbibition.

Vitreous humor is found in vitreous chamber

  • Between lens and retina

  • Between cornea and lens

  • Between sclera and lens

  • Between choroid and lens

Aqueous humor is

  • Thin watery fluid

  • Thick watery fluid

  • Transparent gel

  • Translucent gel

Vitreous humor is

  • Thin watery fluid

  • Thick watery fluid

  • Transparent gel

  • Translucent gel

Which one of the following statements is not correct?

photopigments

  • Retinal is the light absorbing portion of visual photopigments 

  • In retina the rods have the photopigment rhodopsin, while cones have three different

  • Retinal is a derivative of vitamin-C

  • Rhodopsin is the purplish red protein present in rods only 

When we move from dark to light, we fail to see for some time but soon visibility becomes normal. It is:

  • Accommodation
  • Photoperiodism
  • Adaptation
  • Mutation

Unmyelinated nerve fiber is:
 
not enclosed by a myelin sheath
 
form a myelin sheath
 
by a myelin sheath formed by oligodendrocytes
 
somatic neural system
  • Not enclosed by a Schwann cell and hence
  • Enclosed by a Schwann cell that does not
  • Not enclosed by a Schwann cell but enclosed
  • Not found in the autonomous and the

The brain stem does not include :

  • Mid brain 
  • Medulla oblongata
  • Pons varolii
  • Cerebellum 

Which of the following is a major coordinating center for sensory and motor signaling for the cerebrum?

  • Hypothalamus
  • Thalamus
  • Corpora quadrigemina
  • Amygdala

The sensory neuron enters the spinal cord through:

  • The dorsal root of the spinal nerve
  • The ventral root of the spinal nerve
  • Either dorsal or ventral root depending on the point of origin 
  • Both dorsal and ventral roots of the spinal nerves

From inside to outside the correct order of the following cells in the retina would be:

  • Ganglion cells - Photoreceptor cells - Bipolar cells
  • Ganglion cells - Bipolar cells - Photoreceptor cells
  • Bipolar cells - Photoreceptor cells - Ganglion cells
  • Photoreceptor cells - Ganglion cells - Bipolar cells

In the human eye, the visual acuity is highest at:

  • Macula lutea

  • Optic disc

  • Fovea centralis

  • Optic chiasma

Reissner's membrane separates

  • Scala vestibuli and Scala media
  • Tympanic cavity and Pharynx
  • Fenestra rotundus and Fenestra ovalis
  • Scala media and Scala tympani

The resting membrane potential is established primarily due to:

  • Sodium-potassium pump
  • Efflux of potassium
  • Influx of sodium
  • Influx of chloride

A characteristic of human cornea is :

  • absence of blood circulation 
  • cause cataract in old age
  • has lacrimal glands for secreting tears
  • secreted by conjunctiva and glandular layer

Most sensory receptors function by producing depolarising potentials. Which of the following function by hyperpolarization rather than depolarization ?

  • proprioceptors

  • nociceptors
  • olfactory receptors
  • rods and cones

The depolarization of the axonal membrane is due to:

  • Influx of sodium ions

  • Efflux of sodium ions

  • Influx of potassium ions

  • Efflux of the potassium ions

Immediately after an action potential has peaked, which cellular gates open?

  • Sodium

  • Chloride
  • Calcium
  • Potassium

The stapes sends its vibrations to 

  • Incus 
  • Round window
  • Tympanic membrane
  • Oval window

In a chemical synapse, when an impulse arrives at the axon terminal, it:

  • leads to opening of the calcium channels at the post synaptic membrane
  • Stimulates the movement of synpatic vesicles towards the membrane 
  • causes the binding of the neurotransmitter of its receptors on the post synaptic neuron 
  • activates the opening the potassium channels in the axon terminal 

Above the rows of hair cells of Organ of Corti, there is a thin elastic membrane called:

  • Reissner's membrane
  • Basilar membrane
  • Tectorial membrane
  • Tympanic membrane

The vasomotor center that controls the diameter of blood vessels is located in the

  • medulla oblongata

  • pons

  • cerebrum

  • cerebellum

Consider the following statements:

I. Somatic neural system relays impulses from CNS to skeletal muscles.

II. Autonomic neural system transmits impulses from CNS to involuntary organs and smooth muscles

III. Unmyelinated nerve fibres are commonly found in spinal and cranial nerves
Which of the above statements are true?

  • I and II only

  • I and III only

  • II and III only

  • I,II and III

Consider the following statements:

I. The resting axonal membrane is nearly impermeable to sodium ions.

II. Depolarization of the axonal membrane is due to influx of sodium ions.

III. The size of the action potential, if produced, does not depend on the strength of the stimulus.

Which of the above statements are true?

  • I and II only

  • I and III only

  • II and III only

  • I, II and III

Consider the following statements

I. Acetylcholine is released at the electric synapse.

II. Electric synapse are faster

III. It is more difficult to regulate an electric synapse w.r.t. a chemical synapse

Which of the above statements are true?

  • I and II only

  • I and III only

  • II and III only

  • I, II and III

Receptor sites for neurotransmitters are present on

  • membrances of synaptic vesicles
  • pre-synaptic membrane
  • tips of axons
  • post-synaptic membrane

Good vision depends on adequate intake of carotene rich food.

Select the best option from the following statements.

I. Vitamin-A derivatives are formed from carotene.
II. The photopigments are embedded in the membrane discs of the inner segment.
III. Retinal is a derivative of vitamin-A.
IV. Retinal is a light absorbing part of all the visual photopigments.

  • (I) and (II)

  • (I), (III) and (IV)

  • (I) and (III)

  • (II), (III) and (IV)

Myelin sheath is produced by

  • Schwann cells and Oligodendrocytes

  • Astrocytes and Schwann cells

  • Oligodendrocytes and Osteoclasts

  • Osteoclasts and Astrocytes

Choose the correct statement.

  • Nociceptors respond to changes in pressure

  • Meissner's corpuscels are thermoreceptors

  • Photoreceptors in the human eye are depolarised during darkness and become hyperpolarised in response to the stimulus 

  • Receptors do not produce graded potentials

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Practice Zoology Quiz Questions and Answers