Selina Concise Class 7 Biology Solution Chapter No. 6- ‘Nervous System’ For ICSE Board Students.
MULTIPLE CHOICE QUESTION
Put a tick mark against the correct alternative in the following statements.
(1) Medulla oblangata controls
(i) Smelling (ii) Beating of heart and respiratory movement (iii) Intelligence and will power (iv) Balancing of the body
Answer:(ii) Beating of heart and respiratory movement, Which can control the heart beat and gaseous concentration sensation.
(2) Spinal cord is an extension of
(i) Cerebellum (ii) Cerebrum (iii) Vertebral column (iv) Medulla oblangata
Answer:(iv) Medulla oblangata, through the medulla oblangata initiation of spinal cord occurs.
(3) Body posture is maintained by :
(i) Cerebrum (ii) Cerebellum (iii) Medulla oblangata (iv) Spinal cord
Answer:(ii) Cerebellum, it is specialized form balancing the body and maintaining the body posture.
SHORT ANSWER QUESTION
1.) Write one word in space provided to complete the second pair of related words pertaining to nervous system:
Memory : Cerebrum :: breathing :Medulla oblangata
Balance : Cerebellum :: Reasoning :Cerebrum
2.) (a) Name the two major divisions of the human nervous system.
Answer: A) Central Nervous System B) Peripheral Nervous System
(b) Name the three main parts of the human brain.
Answer: A) Cerebrum B) Cerebellum C) Medulla oblangata
3.) Given along side in the diagram of a neuron. Name the parts numbered 1-5.
LONG ANSWER QUESTION (WRITE THE ANSWERS IN YOUR NOTEBOOK)
1.) With the help of a suitable diagram describe the structure of a neuron.
Answer:
The neuron is the structural and functional unit of Central Nervous System. It is responsible for transmission of nerve impulses. The neuron contains cell body and tail. The cell body consist of nucleus and dendrites. At one end of neuron axon terminals are present which passes the signal towards the other end.
2.) Briefly describe the structure of cerebrum in human brain and mention its functions.
Answer: The cerebrum is a part of fore brain, present in upper most region of the brain. The cerebrum made up of two parts such as two cerebral hemispheres. This cerebrum helps in control and coordination of the body. The cerebrum again divides into separate and important lobes of the brain. It downward attach to the brain stem.
3.) Mention the three functions of spinal cord.
Answer:
1) Spinal cord mediates motor, sensory and autonomous functions.
2) It transmit the nerve impulses in the body called as electrochemical impulses.
3) It regulates the body temperature, heart beat, contraction and relaxation of muscles.
4.) Describe three kinds of nerves, giving examples of each.
Answer: From the nervous system, three types of nerves arises. These three types of nerves are sensory, motor and mixed. Sensory nerves also called as afferent nerves. They carry out their function from sense organ or target organ to central nervous system. The second type of nerve called as motor nerve. The motor nerve also called as efferent nerve. These nerves carry out their function fromcentral nervous systemto sense organ or target organ. The mixed nerves are helpful in processing of signals.
5.) What are voluntary and involuntary actions? Which part of the nervous system controls them.
Answer: Voluntary actions are those which are in our own will or control. They can be performed as per own actions. The action can be performed or not depends on person. For example lifting of hand. These actions are controlled by Central Nervous System. The involuntary actions are those which are not in our control. They are carried out by reflexes.