Monday, August 30, 2021

Focus Area 2021 | Questions and Answers | Plus One Zoology | Neural Control and Coordination

NEURAL CONTROL AND COORDINATION


1.   Neurons are the structural and functional units of the neural system. Given below is the structure of a typical neuron. Label A to F. (Score 3)


Answer:

A= Dendrite               

B= Cell body

C= Axon                    

D= Myelin sheath

E= Node of Ranvier  

F= Synaptic knob


2. Distinguish between Electric synapse and Chemical synapse. (Score 2)


Answer:

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 the postsynaptic neuron.


3. 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. (Score 2)

    a) Name the type of synapse A and B.
    b) Name the fluid-filled space in the synapse B.


Answer:

(a) A= Electrical synapse. B= Chemical synapse.

(b) Synaptic cleft.


4. Observe the diagram of a chemical synapse. Label A, B, C & D. (Score 2)


Answer:   

(A) Axon               

(B) Synaptic vesicle

(C) Synaptic cleft  

(D) Neurotransmitters


5. Which part of the brain control respiration and gastric secretions? (Score 1)

    (a) Cerebrum
    (b) Cerebellum
    (c) Medulla 
    (d) Hypothalamus


Answer: (c) Medulla


6. Complete the flow chart given below: (Score 3)


Answer:

(a) Spinal cord                         

(b) Midbrain

(c) Corpora quadrigemina       

(d) Thalamus

(e) Pons                                    

(f) Medulla oblongata


7. Match the following:

Parts of brain

Function

Hypothalamus

Coordinates muscular activities and body equilibrium

Cerebellum

Controls respiration, cardiovascular reflexes, gastric secretions, peristalsis.

Pons

Regulates temperature, thirst, hunger & emotions

Medulla oblongata

Coordinates activities of eye and ear and regulates respiration.


Answer:

Parts of brain

Function

Hypothalamus

Regulates temperature, thirst, hunger & emotions.

Cerebellum

Coordinates muscular activities and body equilibrium.

Pons

Coordinates activities of eye and ear and regulates respiration.

Medulla oblongata

Controls respiration, cardiovascular reflexes, gastric secretions, peristalsis.


8. Cerebral hemispheres of human brain are connected by ................... (Score 1)
    i) association area
    ii) corpus callosum
    iii) corpora quadrigemina
    iv) pons varolii


Answer: (ii) Corpus callosum


9.   a) Prepare a pathway of reflex action (Reflex arc) by using the following hints.

[Hint: Efferent neuron, Receptor, Effector organ, Afferent neuron, Interneuron in the spinal cord]

b) Give an example of reflex action. (Score 3)


Answer:

(a) Receptor → Afferent neuron → Interneuron in the spinal cord →Efferent neuron → Effector organ.

(b) Withdrawal of the hand when it touches a hot object.


10. Distinguish between the following: (Score 2)
(a) Rods and cones.
(b) Blindspot and Yellow spot.


Answer:

(a) Rods: Helps in the twilight (scotopic) vision.

Cones: Helps in daylight (photopic) vision & colour vision.


(b) Blindspot: It is the region slightly above the posterior pole of the eyeball where optic nerves leave the eye. Here, photoreceptor cells are absent.

Yellow spot (Macula lutea): It is a yellowish pigmented spot lateral to the blind spot. Here, only the cones are densely packed.

11. 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.


12.  The innermost layer of the eyeball is ......... (Score 1)
  a) Choroid   

        b) Iris    

        c) Retina             

        d) Sclera


Answer: (c) Retina


13. 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.

14. Match the following: (Score 2)


A

B

Organ of Corti

Middle ear

Eustachian canal

Semicircular canal

Crista

Otolith organ

Macula

Cochlea

Answer:

A

B

Organ of Corti

Cochlea

Eustachian canal

Middle ear

Crista

Semicircular canal

Macula

Otolith organ


15.  Given below is a diagrammatic representation of the sectional view of the cochlea. Label A to F.  (Score 3)


Answer:

A= Reissner’s membrane        

B= Scala media

C= Basilar membrane              

D= Scala tympani

E= Tectorial membrane           

F= Scala vestibuli


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