NEURAL CONTROL & COORDINATION
2020 MARCH
1.
Observe the diagram. (Score 3)
a)
Name the parts A &
B.
b)
Write the characteristics
features of ‘C’.
c)
Arrange the given parts
of eye in the sequence that light travels from the external environment into
the eye.
(Vitreous chamber, lens,
cornea, retina, Aqueous chamber)
Answer:
(a) A= Lens, B= Optic nerve
(b) Macula lutea (yellow spot)- thinned out part of retina.
(c)
Cornea → Aqueous chamber → Lens → Vitreous chamber → Retina.
2019 JULY
1. Which of the part of brain
control respiration and gastric secretions? (Score 1)
(a) Cerebrum (b)
Cerebellum
(c) Medulla (d)
Hypothalamus
Answer:
(c) Medulla
2. Distinguish between the
following: (Score 2)
(a) Electric synapse and Chemical synapse.
(b) Rods and cones.
Answer:
(a) Electric synapse: The membranes of pre- and
post-synaptic neurons are nearer. Faster impulse transmission.
Chemical synapse: There
is a fluid filled space (synaptic cleft) between the presynaptic neuron and
postsynaptic neuron.
(b) Rods: Helps in twilight
(scotopic) vision.
Cones: Helps in daylight (photopic) vision & colour vision.
3. Prepare a flow chart
showing the parts of human brain, by using the details given below: (Score 3)
Cerebrum,
Medulla, Mid brain, Thalamus, Pons, Corpora quadrigemina, Hypothalamus,
Forebrain, Cerebellum, Hind brain, Brain.
Answer:
2019 MODEL
1. a) Identify the below
stages of nerve impulse conduction.
(b) Name the ions involved in this process.
(c) How RMP is maintained? (Score 3)
Answer:
(a) (1)
Stage of resting membrane potential (RMP).
(2) Stage of Depolarisation.
(b) Na+ and
K+ ions.
(c) The RMP is
maintained by the active transport of ions by the Na-K pump. It transports 3 Na+
outwards for 2 K+ into the cell. As a result, the outer surface
becomes positively charged and inner surface becomes negatively charged.
2018 AUGUST
1. Complete the flow
chart given below: (Score 3)
Answer:
(a) Spinal cord
(b) Midbrain
(c) Corpora
quadrigemina
(d) Thalamus
(e) Pons
(f) Medulla oblongata
2018 MARCH
1. The innermost eyeball is
......... (Score 1)
a) Choroid b) Iris c) Retina d) Sclera
Answer:
(c) Retina
2. Complete the given flow chart. (Score 2)
Answer:
(a) Peripheral Neural System
(b) Spinal cord
(c) Autonomic Neural
system
(d) Parasympathetic
2018 MODEL
1. Redraw the diagram. Name
and label the parts indicated below: (Score 3)
A - External layer of
the eye ball.
B - Part where cones are densely packed.
Answer:
(A) Sclera
(B) Yellow spot (macula lutea/ Fovea)
2. In…(a) type of synapse
the membranes of pre-synaptic and post synaptic neurons are in very close
proximity
In…(b)... type of synapse the membrane of pre synaptic and post synaptic
neurons are separated by a fluid filled space.
a) Name the type of synapse A and B.
b) Name the fluid filled space in the synapse B. (Score 2)
Answer:
(a) A= Electrical synapse B= Chemical synapse
(b) Synaptic cleft.
2017 JULY
(IMPROVEMENT)
1. Nerve impulse transmission include generation and propagation of action potential. Write various stages or events in the generation of action potential. (Score 3)
Answer:
1. Maintenance of
resting membrane potential
In a resting neuron, concentration
of K+ and –vely charged proteins in axoplasm is high and
concentration of Na+ is low.
The fluid outside the
axon contains low concentration of K+ and high concentration of Na+.
This forms an ionic or concentration gradient across resting membrane.
The ionic gradients
are maintained by the active transport of ions by the Na-K pump. It transports
3 Na+ outwards for 2 K+ into the cell. As a result, the
outer surface becomes positively charged and inner surface becomes negatively
charged.
The electrical
potential difference across the resting plasma membrane is called resting
potential.
2. Action Potential
When a stimulus is
applied, the membrane at the site A becomes permeable to Na+. This
causes rapid influx of Na+ and reversal of the polarity at that site.
It is called depolarization.
The electrical potential
difference during depolarization across the plasma membrane is called action
potential.
3. Propagation of
action potential
At sites ahead (site
B), outer surface is positive and inner surface is negative. As a result, a
current flows on the inner surface from A to B.
On the outer surface,
current flows from site B to site A to complete the circuit. Hence, the
polarity is reversed and action potential is generated at site B. i.e., action
potential at site A arrives at site B.
OR
2. Observe the
diagram and construct a flow chart to show the mechanism of transmission of
nerve impulse across a chemical synapse. (Score 3)
Answer:
Impulse
transmission through chemical synapse:
Impulse
reaches at axon terminal → synaptic vesicles bind on plasma membrane → release
of neurotransmitter → It diffuses across synaptic cleft → combine with
receptors on the post synaptic membrane → opening of ion channels allowing
entry of ions → generates action potential.
2017 MARCH
1.
Answer the following:
a)
Cerebral hemispheres of human brain are connected by ...................
i)
association area
ii)
corpus callosum
iii)
corpora quadrigemina
iv)
pons varolii (Score 1)
b) Observe the diagram and label A, B, C & D. (Score 2)
Answer:
(a)
ii) corpus callosum
(b)
A= Axon
B= Synaptic
vesicle
C= Synaptic
cleft
D= Neurotransmitters
2016 SEPTEMBER
(IMPROVEMENT)
1. Fovea of Retina of eye contains………. (Score 1)
a.
Rod cells only
b.
Cone cells only
c.
Both Rods and cones
d.
Rods and cones are absent
Answer:
(b) Cone
cells only
2. a) Complete the given table. (Score 2)
(Parts of Human brain)
|
Fore brain |
Hind brain |
|
Parts |
Parts |
|
i) Cerebrum |
i) Pons |
|
ii) Thalamus |
ii) .................. |
|
iii) ................... |
iii) Medulla |
b) Which one of the above parts of brain that controls
gastric secretion?
Answer:
(a)
ii) Cerebellum iii) Hypothalamus
(b) Medulla
2016 MARCH
1. Observe the diagram carefully and answer the following questions. (Score 3)
a) Label the parts marked as A, B, C, D.
b) Identify the photoreceptor cells present in the human eye.
Answer:
(a)
A= Lens, B= Iris, C= Cornea, D= Optic nerve.
(b) Cones
and rods.
2015 SEPTEMBER
(IMPROVEMENT)
1.
Where do you find the following structures in human body? (Score 1)
a.
Cochlea b. Neurotransmitters
Answer:
(a)
Ear (Inner ear)
(b) Chemical
synapse/ Synaptic vesicle
2.
Mention the functions of the following structures in human body. (Hint:
Any two each). (Score 2)
a.
Hypothalamus b. Axon
Answer:
(a) Regulates
temperature, thirst, hunger and emotions.
Controls pituitary gland.
(b) Axon
transmits impulses away from the cell body. Transmits information to different
neurons, muscles, and glands.
2015 MARCH
1.
a) Prepare a pathway of an action by using following hint.
[Hint: Receptor, Motor neuron, Afferent neuron, Efferent neuron, Interneuron
in the spinal cord, Effector organ]
b) Give an example of such an action. (Score 3)
Answer:
(a) Receptor → Afferent neuron → Interneuron
in the spinal cord → Motor neuron → Efferent neuron → Effector organ
(b) Withdrawal of the hand when it
touches a hot object, Knee jerk phenomenon etc.
OR
Compare rods and cones of the retina based
on the following features. (Score 3)
i) Shape
ii)
Type
iii)
Ability to detect colour
iv) Pigments
v) Vision
Answer:
|
Features |
Cones |
Rods |
|
Shape |
Conical |
Cylindrical |
|
Type |
3 types |
1 type |
|
Ability to detect colour |
Yes |
No |
|
Pigments |
Photopsin |
Rhodopsin |
|
Vision |
Photopic vision |
Twilight vision |