1. Acute vision is present in
(a) vulture
(b) shark
(c) bat
(d) frog
2. Sensitive pigmented layer of eye is
(a) cornea
(b) retina
(c) sclerotic
(d) iris
3. Which of the following cranial nerves can regulate heart beat?
(a) X
(b) IX
(c) VIII
(d) VII
4. One function of parasympathetic nervous system is
(a) contraction of hair muscles
(b) stimulation of sweat glands
(c) acceleration of heart beat
(d) constriction of pupil
5. Third ventricle of brain is also known as
(a) metacoel
(b) rhincoel
(c) paracoel
(d) diacoel
6. Vagus nerve is
(a) X
(b) IX
(c) VII
(d) V
7. Afferent nerve fibres carry impulses from
(a) effector organs to CNS
(b) receptors to CNS
(c) CNS to receptors
(d) CNS to muscles
8. Iris is part of
(a) sclerotic
(b) choroid/Uvea
(c) choroid and retina
(d) sclerotic and choroid
9. Function of iris is to
(a) move lens forward and backward
(b) refract light rays
(c) bring about movements of eye lids
(d) alter the size of pupil.
10. Retina is most sensitive at
(a) optic disc
(b) periphery
(c) macula lutea
(d) fovea centralis
11. Light rays entering the eye is
controlled by
(a) pupil
(b) iris
(c) cornea
(d) lens
12. Ivan Pavlov performed experiments on
(a) simple reflexes
(b) conditioned reflexes
(c) cardiac reflexes
(d) origin of life
13. CNS is mostly made of
(a) motor neurons and sensory neurons
(b) sensory neurons and association neurons
(c) association neurons
(d) motor neurons and association neurons
14. Respiratory centre is situated in
(a) cerebellum
(b) medulla oblongata
(c) hypothalamus
(d) cerebrum
15. The sympathetic nerves in mammals arise from
(a) sacral nerves
(b) cervical nerves
(c) thoraco-lumbar nerves
(d) 3rd, 7th, 9th and 10th cranial nerves
16. In humans, visceral organs are innervated by
(a) sympathetic nerves and are under conscious control
(b) parasympathetic nerves and are under conscious control
(c) both sympathetic and parasympathetic nerves and are under conscious control
(d) both sympathetic and parasympathetic nerves but are not under conscious control
17. Cornea transplantation is outstandingly successful because
(a) cornea is easy to preserve
(b) cornea is not linked up with blood vascular and immune systems
(c) the technique involved is very simple
(d) cornea is easily available
18. The Nissl‘s granules of nerve cells are made up of
(a) ribosomes
(b) proteins
(c) DNA
(d) mitochondria
19. In the chemistry of vision in mammals, the photosensitive substance is called
(a) sclerotin
(b) retinol
(c) rhodopsin
(d) melanin
20. Anesthetics reduce pain by blocking the transmission of nerve impulses. The kind of chemicals working as anesthetics are those that block
(a) only the voltage-gated sodium channels in membranes
(b) only the voltage-gated potassium channels in membranes
(c) only the neuro-transmitter receptors
(d) voltage-gated sodium and potassium channels and neuro-transmitter receptors
21. In vertebrates, simple reflex action is
(a) polysynaptic
(b) bisynaptic
(c) trisynaptic
(d) monosynaptic
22. Suspensory ligament is part of
(a) heart
(b) eye
(c) tongue
(d) brain
23. Neuroglia consist of cells found in the
(a) liver
(b) kidney
(c) central nervous system and ganglia
(d) testes
24. What is intensity of sound in normal conversation?
(a) 10—20 decibel
(b) 30—60 decibel
(c) 70—90 decibel
(d) 120—150 decibel
25. When we migrate from dark to light, we fail to see for sometime but after a time visibility becomes normal. It is an example of
(a) accommodation
(b) adaptation
(c) mutation
(d) photoperiodism
26. Characteristic feature of human cornea
(a) Secreted by conjunctiva and glandular
(b) It is lacrimal gland which secretes tears
(c) Blood circulation is absent in cornea
(d) In old age it becomes harden and white layer deposits on it which causes cataract
27. Which of the following statements is correct for ‗nodes of Ranvier‘ of nerve?
(a) Neurilemma is discontinuous
(b) Myelin sheath is discontinuous
(c) Both neurilemma and myelin sheath are discontinuous
(d) Covered by myelin sheath
28. In which animal nerve cell is present but brain is absent?
(a) Sponge
(b) Earthworm
(c) Cockroach
(d) Hydra
29. Ommatidia serve the purpose of photoreception in
(a) sunflower
(b) cockroach
(c) frog
(d) humans
30. Injury to vagus nerve in humans is not likely to affect
(a) tongue movements
(b) gastrointestinal movements
(c) pancreatic secretion
(d) cardiac movements
31. In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive
(a) K+ into the cell
(b) K+ and Na+ out of the cell
(c) Na+ into the cell
(d) Na+ out of the cell
32. Four healthy people in their twenties got involved in injuries resulting in damage and death of a few cells of the following. Which of the cells are least likely to be replaced by new cells?
(a) Liver cells
(b) Neurons
(c) Malpighian layer of the skin
(d) Osteocytes
33. In a man, abducens nerve is injured. Which one of the following functions will be affected?
(a) Movement of the eye ball
(b) Movement of the tongue
(c) Swallowing
(d) Movement of the neck
34. One of the examples of the action of the autonomous nervous system is
(a) swallowing of food
(b) pupillary reflex
(c) peristalsis of the intestine
(d) knee-jerk response
35. During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric change?
(a) First positive, then negative and continue to be positive
(b) First negative, then positive and continue to be positive.
(c) First positive, then negative and again back to positive
(d) First negative, then positive and again back to negative.
36. Which of the following is an example of negative feedback loop in humans?
(a) Secretion of tears after falling of sand particles into the eye.
(b) Salivation of mouth at the sight of delicious food
(c) Secretion of sweat glands and constriction of skin blood vessels when it is too hot
(d) Constriction of skin blood vessels and contraction of skeletal muscles when it is too cold
37. Which one of the following pairs of structures distinguishes a nerve cell from other types of cells?
(a) Vacuoles and fibres
(b) Flagellum and medullary sheath
(c) Nucleus and mitochondria
(d) Perikaryon and dendrites.
38. Given below is a diagrammatic cross section of a single loop of human cochlea: A A B C D Which one of the following options correctly represents the names of three different parts?
(a) B: Tectorial membrane, C: Perilymph, D: Secretory cells
(b) C: Endolymph, D: Sensory hair cells, A: Serum
(c) D: Sensory hair cells, A: Endolymph, B: Tectorial membrane
(d) A: Perilymph, B: Tectorial membrane, C: Endolymph
39. Which one of the following is the correct difference between Rod Cells and Cone Cells of our retina? Rod Cells Cone Cells
(a) Visual: High Low acuity
(b) Visual: IodopsinRhodpsin pigment contained
(c) Overall: Vision in Colour function poor light vision and detailed vision in bright light
(d) Distribu- More conc- Evenly tion: entrated in distributed retina all over
40. During the propagation of a nerve impulse, the action potential results from the movement of:
(a) K+ ions from extracellular fluid to intracellular fluid
(b) Na+ ions from intracellular fluid to extracellular fluid
(c) K+ ions from intracellular fluid to extracellular fluid
(d) Na+ ions from extracellular fluid to intracellular fluid
41. Cornea transplant in humans is almost never rejected. This is because
(a) its cells are least penetrable by bacteria
(b) it has no blood supply
(c) it is composed of enucleated cells
(d) it is a non-living layer
42. Alzheimer disease in humans is associated with the deficiency of:
(a) glutamic acid
(b) acetylcholine
(c) gamma aminobutyric acid (GABA)
(d) dopamine
43. Which part of human brain is concerned with the regulation of body temperature?
(a) Cerebellum
(b) Cerebrum
(c) Hypothalamus
(d) Medulla Oblongata
44. The nerve centres which control the body temperature and the urge for eating are contained in:
(a) hypothalamus
(b) pons
(c) cerebellum
(d) thalamus
45. When a neuron is in resting state I not conducting any impulse, the axonal membrane is:
(a) comparatively more permeable to Na+ ions and nearly impermeable to K+ ions
(b) equally permeable to both Na+ and K+ ions
(c) impermeable to both Na+ and K+ ions
(d) comparatively more permeable to K+ ions and nearly impermeable to Na+ ions
46. The purplish red pigment rhodopsin contained in the rods type of photoreceptor cells of the human eye, is a derivative of:
(a) vitamin B1
(b) Vitamin C
(c) vitamin D
(d) vitamin A
47. The human hind brain comprises three parts, one of which is:
(a) Spinal cord
(b) Corpus callosum
(c) Cerebellum
(d) Hypothalamus
48. Which part of the human ear plays no role in hearing as such but is otherwise very much required?
(a) Eustachian tube
(b) Organ of corti
(c) Vestibular apparatus
(d) Ear ossicles
49. A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his
neuro-hormonal control system?
(a) Sympathetic nervous system is activated releasing epinephrin and norepinephrin from adrenal medulla.
(b) Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse.
(c) Hypothalamus activates the parasympathetic division of brain.
(d) Sympathetic nervous system is activated releasing epinephrin and norepinephrin from adrenal cortex.
50. The most abundant intracellular cation is:
(a) Ca++
(b) H+
(c) K+
(d) Na+
51. Insulin is
(a) vitamin
(b) lipid
(c) hormone
(d) enzyme
52. A person, who shows unpredictable moods, outbursts of emotion, quarrelsome behavior and conflicts with others, is suffering from
(a) mood disorder
(b) addictive disorder
(c) borderline personality disorder (BPD)
(d) schizophrenia
53. Myelin sheath is produced by
(a) osteoclasts and astrocytes
(b) Schwann cells and oligodendrocytes
(c) astrocytes and Schwann cells
(d) oligodendrocytes and osteoclasts
54.Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements.
(1) Vitamin A derivatives are formed from carotene.
(2) The photopigments are embedded in the membrane discs of the inner segment.
(3) Retinal is a derivative of vitamin A.
(4) Retinal is a light absorbing part of all the visual photopigments.
(a) (1) and (3)
(b) (2), (3) and (4)
(c) (1), (3) and (4)
(d) (1) and (2)]
55. Destruction of the anterior horn cells of the spinal cord would result in loss of
(a) commissural impulses
(b) integrating impulses
(c) sensory impulses
(d) voluntary motor impulses.
56. The junction between the axon of one neuron and the dendrite of the next is called
(a) constant bridge
(b) junction point
(c) a joint
(d) a synapse
57.Injury localized to the hypothalamus would most likely disrupt
(a) short term memory
(b) coordination during locomotion
(c) executive functions, such as decision making
(d) regulation of body temperature.
58. Otorhinolaryngology is the study of
(a) brain cells
(b) ENT
(c) bird anatomy
(d) locomotary organs
59. The human hind brain comprises three parts, one of which is
(a) spinal cord
(b) cerebellum
(c) corpus callosum
(d) hypothalamus.
60. When a neuron is in resting state i.e., not conducting any impulse, the axonal membrane is
(a) comparatively more permeable to Na+ ions and nearly impermeable to K+ ions
(b) equally permeable to both Na+ and K+ ions
(c) impermeable to both Na+ and K+ ions
(d) comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.
61. What is correct for the resting potential
(a) On innerside of plasma membrane + ve charge & outerside -ve charge is found
(b) On outerside Na+ concentrartion is less ,on innersde k + concentrtion is less
(c) On outerside a plasma membrane + ve charge and innerside is -ve charge
(d) Electrically it is neutral in resting stage.
62.In mammalian eye, the ‘fovea’ is the center of the visual field, where
(a) only rods are present
(b) more rods than cones are found
(c) high density of cones occur, but has no rods
(d) the optic nerve leaves the eye
63. During the propagation of a nerve impulse, the action potential results from the movement of
(a) K+ ions from intracellular fluid to extracellular fluid
(b) Na+ ions from extracellular fluid to intracelluar fluid
(c) K+ ions from extracellular fluid to extracellular fluid
(d) Na+ ions from intracellular fluid to extracellular fluid.
64. During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric change?
(a) First negative, then positive and continue to be positive
(b) First positive, then negative and continue to be negative
(c) First positive, then negative and again back to positive
(d) First negative, then positive and again back to negative.
65. Bowman’s glands are found in
(a) olfactory epithelium
(b) external auditory canal
(c) juxtamedullary nephrons
(d) cortical nephrons only
66. In a man, abducens nerve is injured. Which one of the following functions will be affected?
(a) Movement of the eyeball
(b) Movement of the tongue
(c) Movement of the neck
(d) Swallowing
67. Which of the following is not related to fore brain ?
(a) lateral ventricle
(b) Corpus callosum
(c) Voluntary locomotion
(d) Inferior Collicule
68. Which of the following statement is correct for node of Ranvier of nerve?
(a) Both neurilemma and myelin sheath are discontinuous
(b) Covered by myelin sheath
(c) Neurilemma is discontinuous
(d) Myelin sheath is discontinuous
69.The most abundant intracellular cation is
(a) H+
(b) K+
(c) Na+
(d) Ca++
70. Which part of the human ear plays no role in hearing as such but is otherwise very much required?
(a) Eustachian tube
(b) Organ of Corti
(c) Vestibular apparatus
(d) Ear ossicles
71. Cornea transplant in humans is almost never rejected. This is because
(a) it is composed of enucleated cells
(b) it is a nonliving layer
(c) its cells are least penetrable by bacteria
(d) it has no blood supply.
72. Myelin sheath is produced by :
(a) Astrocytes and Schwann cells
(b) Oligodendrocytes and Osteoclasts
(c) Osteoclasts and Astrocytes
(d) Schwann cells and Oligodendrocytes
73. Which of the following structures or regions is incorrectly paired with its functions?
(a) Medulla oblongata : controls respiration and cardiovascular reflexes.
(b) Limbic system : consists of fibre tracts that interconnect different regions of brain; controls movement.
(c) Corpus callosum : band of fibers connecting left and right cerebral hemispheres.
(d) Hypothalamus : production of releasing hormones and regulation of temperature, hunger and thirst.
74. A temporary endocrine gland in the human body is :
(a) Corpus cardiacum
(b) corpus luteum
(c) Corpus allatum
(d) Pineal gland
75.Receptor sites for neurotransmitters are present on :
(a) Pre-synaptic membrane
(b) Tips of axons
(c) Post-synaptic membrane
(d) Membrane of synaptic vesicles
76. Good vision depends on adequate intake of carotene rich food :
Select the best option from the following statements :
(a) Vitamin A derivatives are formed from carotene
(b) The photopigments are embedded in the membrane discs of the inner segment
(c) Retinal is a derivative of Vitamin A
(d) Retinal is a light absorbing part of all the visual photopigments
Options :
(1) (a), (c) and (d)
(2) (a) and (c)
(3) (b), (c) and (d)
(4) (a) and (b)
77. The transparent lens in the human eye is held in its place by
(a) ligaments attached to the ciliary body
(b) ligaments attached to the iris
(c) smooth muscles attached to the ciliary body
(d) smooth muscles attached to the iris
78. Nissl bodies are mainly composed of
(a) Proteins and lipids
(b) DNA and RNA
(c) Free ribosomes and RER
(d) Nucleic acids and SER
79. Which part of the brain is responsible for thermoregulation?
(a) Cerebrum
(b) Hypothalamus
(c) Corpus callosum
(d) Medulla oblongata
80. Which of the following statements is correct?
(a) Cornea is an external, transparent and protective proteinacious covering of the eye-ball.
(b) Cornea consists of dense connective tissue of elastin and can repair itself.
(c) Cornea is convex, transparent layer which is highly vascularised.
(d) Cornea consists of dense matrix of collagen and is the most sensitive portion the eye.
81. Match the following hormones with the respective disease
(a) Insulin (i) Addison’s disease
(b) Thyroxin (ii) Diabetes insipidus
(c) Corticoids (iii) Acromegaly
(d) Growth Hormone (iv) Goitre
(v) Diabetes mellitus
Select the correct option.
(a) (b) (c) (d)
(1) (v) (i) (ii) (iii)
(2) (ii) (iv) (iii) (i)
(3) (v) (iv) (i) (iii)
(4) (ii) (iv) (i) (iii)
82. Which of the following would help in prevention of diuresis?
(1) Atrial natriuretic factor causes vasoconstriction
(2) Decrease in secretion of renin by JG cells
(3) More water reabsorption due to undersecretion of ADH
(4) Reabsorption of Na+ and water from renal tubules due to aldosterone
83. Match the following columns and select the correct option.
Column-I Column-II
(a) Organ of Corti (i) Connects middle ear and pharynx
(b) Cochlea (ii) Coiled part of the labyrinth
(c) Eustachian tube (iii) Attached to the oval window
(d) Stapes (iv) Located on the basilar membrane
(a) (b) (c) (d)
(1) (iv) (ii) (i) (iii)
(2) (i) (ii) (iv) (iii)
(3) (ii) (iii) (i) (iv)
(4) (iii) (i) (iv) (ii)
84. The plant hormone used to destroy weeds in a field
(1) IBA
(2) IAA
(3) NAA
(4) 2, 4-D
Solutions :
1.Solution: (a) Vulture, some other birds and man have acute vision.
2.Solution: (b) Retina has 2 layers, an outer heavily pigmented (melanin containing) layer and an inner neurosensory layer. The inner
layer consists of rods and cones, bipolar nerve cells and large ganglionic nerve cells.
3.Solution: (a) Xth pair of cranial nerves (vagus nerves) has a motor branch called cardiac nerve which innervate cardiac muscles.
4.Solution: (d) Sympathetic system prepares the body for stress or emergency conditions while parasympathetic system is associated with
the period of rest. So when one faces the stress or emergency conditions sympathetic stem enlarges the pupil to allow more light in the eye while during rest parasympathetic nervous system constricts the pupil to its normal condition.
5.Solution: (d) It is the cavity of diancephelone which is connected ahead with the lateral ventricles or paracoel of cerebral hemisphere by
foramen of Monro& behind with the iter (the duct of midbrain). The ventral wall of diocoel in known as hypothalamus.
6.Solution: (a) Vagus nerve is 10th pair of nerves arising from medulla oblongata of brain. These are mixed nerves i.e. having both sensory as
well as motor nerve fibres.
7.Solution: (b) Afferent nerve fibres – sensory nerve fibres which carry senses from receptors to brain or spinal cord (CNS). Efferent nerve fibres –
motor nerve fibres carry orders or responses from CNS to effectors (muscles and glands).
8.Solution: (c) Iris consists of two layers, outer thickened layer is continuation with choroid and inner simple cuboidal epithelium layer continued from retina.
9.Solution: (d) Iris controls the size of pupil by contracting or relaxing of its circular muscles. It controls the amount of light entering in eye.
10.Solution: (d) Fovea centralis is the most sensitive part of retina (in fact most sensitive part of the eye). This is the area of most acute vision.
Actually it is a small depression present in mammals (not in frog) at macula lutea or yellow spot.
11.Solution: (a) Pupil is the opening which controls the amount of light entering in eye. When light intensity is high, it decreases in size and
when light intensity is low it dilates to allow more light in the eye to make eye enable to see the object.
12.Solution: (b) Conditioned reflexes (reflexes developed by training and learning) were first demonstrated by Russian Scientist Ivan Pavlov in dogs. He used to ring the bell while giving the food to his dog, after some time when only bell is rung watering of mouth started in dog i.e. dog learnt a close association of food and bell and it gets into dog‘s reflexes.
13.Solution: (c) Association neurons.
14.Solution: (b) Respiratory centre is situated bilaterally in medulla oblongata, while breathing is controlled by pneumotaxic and apneustic
centres in pons varolii. Impulse for voluntary forced breathing starts in cerebral hemisphere.
15.Solution: (c) In mammals, the sympathetic nerves arise from thoraco-lumbar nerves (autonomic nervous system).
16.Solution: (d) The activities of all visceral organs are coordinated through the regulation of their smooth muscles and glands by the nerve
fibres of the sympathetic and parasympathetic nervous system. These constitute the autonomic nervous system which carry out functions that are not under the control of our will.
17.Solution: (b) Cornea transplants are easy, since there are no blood vessels involved.
18.Solution: (a) Prominent granules (Nissl‘s granules) observed in the cytoplasm of the cyton are believed to be made of ribosomes. A Nissl
body (or Nissl granule or tigroid body) is a large granular body found in nerve cells. It was named after Franz Nissl, German neurologist (1860-1919). Nissl bodies can be demonstrated by selective staining, which was developed by Nissl and the stain used was an aniline stain to label
extranuclear RNA granules.These granules are rough endoplasmic reticulum (with ribosomes) and are the site of protein synthesis.Nissl bodies show changes under various physiological conditions and in pathological conditions they may dissolve and disappear (karyolysis).
19. Solution: (c) Melanin is the pigment which gives colour to the skin. Retinol is the other name for vitamin A. Sclerotin is the component of the carapace in crustaceans.
20.Solution: (d) In this manner, they block transmission of nerve impulse.
21.Solution: (d) A reflex action is a nerve mediated spontaneous, automatic and involuntary response to a stimulus acting through specific receptors without consulting the will of the animal.
22.Solution: (b) Stretching and relaxation of suspensory ligament changes the focal length of lens for accommodation.
23.Solution: (c) Neuroglia are non-nervous cells presentalong with and in between the neurons in central nervous system, ganglia and retina. They have roles like myelin formation, transport of materials to neurons, maintenance of ionic balance and phagocytosis.
24.Solution: (b) The word noise is taken from the latin word nausea and is defined as unwanted or unpleasant sound that causes discomfort.
Source Intensity (dB) Breathing 10 Broadcasting studio 20 Trickling clock 30 Library 30 – 35 Normal conversetion 35 – 60 Telephone office Noise 60 – 80 Alarm clock 70 – 80 Traffic 50 – 90 Motorcycle 105 Jet fly over 100 – 110 Train whistle 110 Air craft 110 – 120
25.Solution: (b) It takes some time for rhodopsin to split into scotopsin and retinal (bleading) and release of transmitter passing nerve inpulse
via bipolar and ganglion cells to the optic nerves. This is a case of adaptation. It differs from accomodations which is a reflex mechanism by which the focus of the eye change to make the images of distant and near objects sharp on the retina.
26.Solution: (c) The outermost layer of the eye ball is fibrous in nature. Two-third part of this layer is opaque and lies inside the eyeorbit and is known as sclera.The remaining onethird of the outer layer is transparent and bulges out to form the cornea.There is no supply of blood in cornea.
27.Solution: (b) Neurons are the chief functional units of the nervous system. An ordinary neuron has a soma or cyton and a long thread called axon which is enclosed in a multilayered myelin sheath, made by Schwann cells. The myelin sheath is interrupted at the spaces between schwann cells to form gaps. These gaps are called Nodes of Ranvier. These nodes and the myelin sheath create condition that speed up the nerve impulses.
28.Solution: (d) A primitive type of nervous system, without brain is found in the form of intra epidermal nerve net. However, there is no brain in Hydra to coordinate the response.
29.Solution: (b) Cockroach has compound eye composed of many units called ommatidia. It comprises a cornea lens, crystalline cone, a graph of
usually 7–8 retinal cells radially arranged around a central rhabdome
30.Solution: (a) Muscles of the tongue are invested by the 12th cranial nerve, Hypoglossal. The 10th cranial nerve, vagus supplies the viscera of
the thorax, abdominal region and thus controls gastrointestinal, cardiac movements and pancreatic secretion.
31. Solution: (c) In a resting state of the neural membrane, Na+ concentration is higher on the outer side and K+ concentration is more within
the cell. This concentration gradient is maintained by voltage gated channels. Hence if diffusion is allowed Na+ would enter the cell and K+ would leave.
32.Solution: (b) The neurons are cells specialised to conduct an electrochemical current. Neuron cells do not have the capability of division.
33.Solution: (a) Abducens nerve is the sixth cranial nerve. It supplies the extraocular muscle (superior oblique) of eyeball, therefore controls
movement of the eyeball.
34.Solution: (c) Autonomic nerveous system regulates and coordinates involuntry activities like heart beat, homeostasis, body temperature,
breathing, gut peristalsis and secretion of glands. Human intestine shows movements during food digestion called peristalsis.
35.Solution: (d) Once the events of depolarization have occurred, a nerve impulse or spike is initiated. Action potential is another name of nerve impulse. It lasts about 1 msec (millisecond). The stimulalted, negatively charged point on the outside of the membrane sends out an electrical current to the positive point (still polarized adjacent to it). This local current causes the adjacent inner part of the membrane to reverse its potential from –70 mV to +30 mV. The reversal repeats itself over and over until the nerve impulse is conducted through the length of the neuron.
36.Solution: (d) When the set point of hypothalamus is disturbed by high temperature, it stimulates vasodilation and sweating while in low temperature there is vasoconstriction and shivering.
37.Solution: (d) The cytoplasm immediately surrounding the nucleus is loaded with protein synthetic machinery and is called perikaryon,
dendrites are usually shorter, tapering and much branched processes which may be one to several. These two are only present in nerve cells.
38.Solution: (d) The diagramnatic cross section of a single loop of human cochlea represents the three different partsA- Perilymph B- Tertorial
membrane C-Endolymph Cochlea arises from sacculus. It is spirally coiled duct. It is also known as Lagena. It is connected with sacculus by duct of Reunies.
39.Solution: (c) Rod cells is a type of light sensitive receptor cell present in the retinas of vertebrates. Rod contains the pigment rhodopsin and are essential for vision in dim light. Cone cells is a type of light sensitive receptor cell, found in retinas of all diurnal vertebrates. Cones are specialized to transmit information about colour and are responsible for the visual acuity of the eye. They function best in bright light.
40.Solution: (d) Total sum of physio-electrochemical changes that takes place along the length of nerve fibre is known as nerve impulse. Change in potential due to stimulation of nerve fibre is called action potential. During propagation of nerve impulse, Na+ enters inside so (+ve) change is formed inside the membrane. K+ ions come out.
41.Solution: (b) Cornea transplant in humans is almost never rejected. This is because it has no blood supply. Cornea is a transparent layer
of tissue, continuous with the sclerotic, that forms the front part of the vertebrate eye, over the iris and lens.
42.Solution: (b) Alzheimer disease in humans is associated with the deficiency of acetylcholine. Acetylcholine is the neurotransmitter
produced by neurons referred to as cholinergic neurons. Acetylcholine plays a role in skeletal muscle movement, as well as in the regulation of smooth muscle and cardiac muscle. Acetylcholine is synthesized from choline and acetyl coenzyme-A through the action of the enzyme choline acetyltransferase and becomes packaged into membranebound vesicles.
43.Solution: (c) Hypothalamus part of human brain is concerned with the regulation of body temperature. The hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions. The hypothalamus is small cone-shaped structure, projects downward, ending in the pituitary.
44.Solution: (a) Hypothalamus contains important nerve centres that controls the body temperature, thirst, hunger and eating, water balance
and sexual function.
45.Solution: (d) When a neurone is in resting state i.e., not conducting any impulse, the axonal membrane is comparatively more permeable to K+ ion and nearly impermeable to Na+ ions.
46.Solution: (a) Rhodopsin contained in the rod type of photoreceptor cells of human eye is a derivative of vitamin B1.
47.Solution: (c) The human hind brain comprises of pons, cerebellum and medulla oblongata.
48.Solution: (c) Vestibular apparatus is a part of inner ear which has no role in hearing but responsible for the maintenance of balance
of the body and posture.
49.Solution: (a) Epinephrine and norepinephrine are secreted by adrenalmedulla in response to stress of any kind and during emergency
situations and are called emergency hormones or hormones of flight, or fight.
50.Solution: (c) The most abundant intracellular cation is K+.
51.Solution: (c) Insulin is a hormone secreted by the bcells of pancreas and it controls the sugar level in blood.
52.(c) A mental disorder characterised by unstable moods, behaviour and relationships. The cause of borderline personality disorder isn’t well understood. Diagnosis is made based on symptoms. Symptoms include emotional instability, feelings of worthlessness, insecurity, impulsivity and impaired social relationships.
53. (b) Myelin sheath wrapped around the nerve axon. Oligodendrocytes are neuroglial cells which produce myelin sheath in central nervous system while Schwann cell produces myelin sheath in peripheral nervous system.
54.(c) 1,3 and 4
55.(d) voluntary motor impulses
56.(d) Synapse is the close proximity of the axon of one neuron and the dendrite or cyton of another neuron with a gap of just about 200 Å in between. A nerve impulse is transmitted across the synapse by the release from the presynaptic membrane of neurotransmitter, which diffuses across the synaptic cleft to the post synaptic membrane. This triggers the propagation of the impulse from the dendrite along the length of the post synaptic neuron.
57.(d) The hypothalamus is a small region of the brain. It’s located at the base of the brain, near the pituitary gland While it’s very small, the hypothalamus plays a crucial role in many important functions, including: releasing hormones. regulating body temperature.
58.(b) Otorhinolaryngology is the study of ENT that means ear, nose and throat.
59.(b) Human hind brain comprises pons, cerebellum and medulla (also called the medulla oblongata).
60.(a) When a neuron is not conducting any impulse, i.e., resting, the axonal membrane is comparatively more permeable to potassium ions (K+) and nearly impermeable to sodium ions.
61.(a) On outerside a plasma membrane + ve charge and innerside is -ve charge
62. (c) A small oval, yellowish area of the retina lying exactly opposite the centre of the cornea is named the macula lutea or yellow spot which has at its middle a shallow depression, the fovea centralis. The fovea centralis has cone cells only. It is devoid of rods and blood vessels. The fovea centralis is the place of most distinct vision.
63.(b) Action potential is the change in electrical potential that occurs across a plasma membrane during the passage of a nerve impulse. As an impulse travels in a wavelike manner along the axon of a nerve, it causes a localized and transient switch in electric potential across the membrane from – 60 mV (millivolts; the resting potential) to + 45 mV. It is due to the fact that the sodium channels open and the potassium channels remain closed. As a result, sodium channels permit the influx of Na+ by diffusion from extracellular fluid to intracellular fluid.
64.(d) First negative, then positive and again back to negative
65.(a) Olfactory glands, also known as Bowman’s glands, are a type of nasal gland situated in the olfactory mucosa, beneath the olfactory epithelium, in the lamina propria, a connective tissue also containing fibroblasts, blood vessels and bundles of fine axons from the olfactory neurons.
66. (a) movement of eye ball
67. (d) Inferior Collicule. The inferior colliculus is a part of the midbrain that serves as a main auditory (sound) center for the body. It acts as the channel for almost all auditory signals in the human body. Its primary roles are signal integration, frequency recognition, and pitch discrimination.
68.(d) At the level of node of Ranvier the myelin sheath is discontinuous but not the neurilemma lining. Actually myelin sheath is an integral part of Schwann’s cell – which form a continuous neurilemmal covering. Each Schwann’s cell wrap-around the neurite to form concentric layers of plasma membrane. But at the level of junction between two Schwann’s cells myelin can not be formed and thus a gap appears.
69. (b) Major intracellular cation is K+ Major extracellular cation is Na+ Ca+ play major role in signal transduction pathways. H+ is found in aqueous solution of all ac
70.(c) bular system, apparatus of the inner ear involved in balance. The vestibular system consists of two structures of the bony labyrinth of the inner ear, the vestibule and the semicircular canals, and the structures of the membranous labyrinth contained within them. The vestibular system is the sensory apparatus of the inner ear that helps the body maintain its postural equilibrium. The information furnished by the vestibular system is also essential for coordinating the position of the head and the movement of the eyes.
71. (d) Cornea is a transparent layer of tissue continuous with sclerotic that forms the front part of vertebrate eye over the iris and lens. It refracts light waves entering the eye onto lens. Cornea is avascular (i.e., has no blood supply). It is one of the first organs to be successfully transplanted because it lacks blood vessels.
72(d)Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells. chwann cells make myelin in the peripheral nervous system (PNS: nerves) and oligodendrocytes in the central nervous system (CNS: brain and spinal cord). In the PNS, one Schwann cell forms a single myelin sheath By contrast, in the CNS, the oligodendrocyte sends cell processes to myelinate multiple segments on many axons.
73(b) The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involuntary) functions, ranging from vomiting to sneezing. It plays an essential role in passing messages between your spinal cord and brain. It’s also essential for regulating your cardiovascular and respiratory systems.
The limbic system is a set of structures in the brain that deal with emotions and memory. It regulates autonomic or endocrine function in response to emotional stimuli and also is involved in reinforcing behavior .
The corpus callosum is a large, C-shaped nerve fiber bundle found beneath the cerebral cortex. It stretches across the midline of the brain, connecting the left and right cerebral hemispheres. It makes up the largest collection of white matter tissue found in the brain.
The hypothalamus is a part of the brain that has a vital role in controlling many bodily functions including the release of hormones from the pituitary gland
74 (b) The Corpus luteum is a temporary endocrine gland in the human body because it is only formed during pregnancy conditions in the woman.
A corpus luteum is a mass of cells that forms in an ovary and is responsible for the production of the hormone progesterone during early pregnancy. The role of the corpus luteum depends on whether or not fertilization occurs. Sometimes, cysts can form in a corpus luteum, which can lead to painful symptoms.
the corpus allatum is an endocrine gland which generates juvenile hormone; as such, it plays a crucial role in metamorphosis.
The pineal gland is a small, pea-shaped gland in the brain. Its function isn’t fully understood. Researchers do know that it produces and regulates some hormones,
75(c) In a chemical synapse, the postsynaptic membrane is the membrane that receives a signal (binds neurotransmitter) from the presynaptic cell and responds via depolarisation or hyperpolarisation.
Neurotransmitters are chemical messengers that transmit a message from a nerve cell across the synapse to a target cell. The target can be another nerve cell, or a muscle cell, or a gland cell. They are chemicals made by the nerve cell specifically to transmit the message.
76. (a) Carotene is the chief source of Vitamin A derivative, Retinal. Retinal is he light absorbing part of all photopigments
77 (a) Lens in the human eye is held in its place by suspensory ligaments attached to the ciliary body.
The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The aqueous humor is produced in the non-pigmented portion of the ciliary body
78 (c) A Nissl body, also known as Nissl substance and Nissl material, is a large granular body found in neurons. These granules are of rough endoplasmic reticulum (RER) with rosettes of free ribosomes, and are the site of protein synthesis.
79(b) The hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland.
80 (d) Cornea consists of dense matrix of collagen and corneal epithelium. It is the most sensitive part of eye. The covering of the eye ball is not cornea but mainly sclera. Cornea only covers one-third part.
81 (c) Insulin deficiency leads to diabetes mellitus
A goiter can sometimes occur when your thyroid gland produces too much thyroid hormone. In someone who has Graves’ disease, antibodies produced by the immune system mistakenly attack the thyroid gland, causing it to produce excess thyroxine.
82(d)
• Less water reabsorption takes place due to under secretion of ADH. ADH constantly regulates and balances the amount of water in your blood.
• Atrial natriuretic factor (ANF) causes vasodilation and thereby decrease the blood pressure.
• Diuresis is prevented by increase in secretion of renin by JG cells.
83(a) The organ of Corti is a specialized sensory epithelium that allows for the transduction of sound vibrations into neural signals. The organ of Corti itself is located on the basilar membrane.
The cochlea is the coiled portion of the bony labyrinth in the petrosal portion of the temporal bone that contains perilymph.
The eustachian tube is a canal that connects the middle ear to the nasopharynx, which consists of the upper throat and the back of the nasal cavity.
The stapes, which is the smallest bone in the human body, is also the last of the three auditory ossicles. It is connected to the oval window.
84 (c) Some synthetic auxins are used as weedicides. 2,4-D is widely used to remove broad leaved weeds or dicotyledonous weeds in cereal crops or
monocotyledonous plants. IAA and IBA are natural auxins. NAA is a synthetic auxin.
