CBSE : Class X : Science : Chapter 7 : Control and Coordination : Question and Answer

  • Check with Publisher
  • Published date: August 23, 2018
  • Modified date: January 27, 2019
    • Vasai East, Thane, Maharashtra

Q1: Write short notes on Control and cordinations ?


Ans : -
Every living organism has a property called sensitivity to show responses to environmental changes. This environmental changes are called stimuli. Organisms responds to stimuli in various ways. Animals have special cells called neurons which are called structural functional unit of nervous system. It receives information from the surrounding, interpret it and respond accordingly. Information is detected by of neurons. The receptors are usually located in sense receptors and are usually located in sense organs like nose, tongue, ear, skin etc.

For eg :  Gustatory receptors will detect taste while olfactory receptors will detect smell.


Control and Coordination In Animals:


* Unicellular organisms responds to stimuli either by maoving towards or away from it.


* In lower animals like hydra, jellyfish, a net of of nervous cells helps in conduction of impulses.


* In higher animals, the information from stimuli is received by following receptors :


a) Photo-receptors ------> Sensitive to light


b) Phono-receptors -------> Senstivity to sound


c) Olfactory receptors -----> Sensitivity to smell


d) Thermo-receptors --------> Sensitivity to temperature


e) Tango-receptors --------> Sensitivity to touch.


* In vertebrates, nervous system consists of brain, spinal chord and nerves. Beside these, hormones from endocrine gland also help in control and coordinations.


Q 2: Write short notes on Human Nervous System:


Ans : Human nervous system consists of :


i) Central nervous system : The brain and spinal chord constitutes central nervous system. They receive information from all parts of body and integrate it.


ii) Peripheral nervous system : Peripheral nervous system consists of cranial nerves arising from the brain and spinal nerves arising from the spinal chords. They facilitate communication between the central nervous system and the other part of body.


Iii) Autonomic nervous system : The organs of our body , such as the heart, intestines and stomach, are regulated by a branch of the nervous system known as the autonomic nervous system. Its of two type : sympathetic nervous system and parasympathetic nervous system. Both of these have opposite effect on gland and internal organs. For eg: Sympathetic system increases the contraction of heart while parasympathetic decreases.


iv) Nervous system performs following function:


a) Receives messages from sense organs.


b) Analyse the message and decide action.


c) Send instructions to concerned muscles.


Q3: What are neurons ?


Ans :


 I) These are structural and functional unit of nervous system and are longest cell in human body.


 ii) Neurons consists of cell body, dendrites and axon.


 Iii) Dendrites are short and highly branched to reach the remote part of the body and conduct impulses.


 iv) Axon is thin, long extension carrying impulses away from the cell body.


 v) Axon is surrounded by myelin sheath which increases the speed of nerve impulses and insulate axon.


 vi) The ending of axon are branched and called synaptic terminal.


 vii) The gap between synaptic terminal and dendrites of next neuron is called synapse.


 Q4: What are various types of neuron ?


 Ans : Following are various types of neuron :


 a) Sensory neuron : Sensory neuron carry message from receptor organs through central nervous system. It is also called as afferent neuron.


 b) Motor neuron : They take message from central nervous system to effector organs.


 c) Relay neuron : It occurs between sensory and motor neuron and passes nerve impulses from neuron to other. They are also called mixed neuron or interneuron.


 Q5: Explain the process of transmission of nerve impulse.


 Ans :


 i) Stimulus received by the receptor is passed in the form of chemical.


 ii) The information acquired by dendrites, sett off a chemical reaction that creates electrical impulses.


 Iii) This electrical impulses travels from dendrite to cell body.


 iv) At the end of the axon, the electrical impulse set off release of some chemicals called neurotransmitter. These chemicals cross the gap or synapse, and start a similar electrical in dendrites of the next neuron.


 Q6: What are various component of human brain ?


 Ans: Human brain consists of :


 Brain : It is protected by cranium and three layered membrane called meninges which are filled with cerebrospinal fluid that mechanical shock. Brain is divisible into fore brain, mid brain and hind brain.


 i) Fore Brain :


 a) It consists of cerebral hemisphere and called cerebrum.


 b) Its surface has many fold called cerebral cortex which increase the surface area of and the number of neurons.


 c) It is the center of intelligence and voluntary movements.


 d) It also control mental abilities like thinking, reasoning, memorising etc.


 e) Fore brain receives sensory impulses from various receptors.


 ii) Mid brain :


 a) It includes optic nervous which are center of vision and also control voluntary actions of head and neck.


 b) It also relays information to fore brain and hind brain.


 iii) Hind Brain :


 a) It consist of Pons, Medulla oblongata, and cerebellum.


 b) It controls posture and maintain body balance. It also controls some voluntary action likes writing, walking etc…


 c) Pons relay information between cortex and cerebellum. It also regulates rate of respiration.


 d) Medulla oblongata is the center of involuntary actions like coughing, sneezing, vomiting, salivation etc…..


 e) It continued as spinal cord.


 Q6: Write short notes on spinal cord.


 Ans: Spinal cord is long, cylindrical arising from medulla and run through vertebrae column. It is covered by meninges filled with cerebrospinal fluid. It conducts and integrates sensory and motor impulses to and from brains. It is the major center of reflex action.


 Q7: What is reflex action ?


 Ans:


 i) Reflex action is spontaneous involuntary response to stimuli.


 ii) These actions are produced by reflex arc from anywhere along the spinal cord.


 Iii) A reflex arc is formed by sensory and motor neurons joined by relay neurons connecting nerves present in spinal cords.


 iv) Reflex arc is very effective in quick response.


 Q8: Write short notes on Endocrine system.


 Ans:


 i) Endocrine system consist of endocrine glands (ductless glands) which don’t have duct and pour their secretions directly into the blood. These secretion of endocrine glands is called hormones.


 ii) Hormones are chemicals that are synthesised in one part of the body and translocate it to the other part for triggering physiological reactions.


 


 


Type of Question: Question and Answer
Vote
Result 4 votes

Youtube video

Share by email Share on Facebook Share on Twitter Share on Google+ Share on LinkedIn Pin on Pinterest
Viewed 153 times
 

Useful information

  • All the CBSE students, teachers and Mentors can post question and Answer
  • The publisher will be sole responsible for accuracy of Answers and published Contents.
  • The site will not be responsible for any damage, fraud or any other act which might impact users of this portal.
  • This site is never involved in any transaction, and does not handle payments, shipping, guarantee transactions, provide escrow services etc.

Leave your comment (spam and offensive messages will be removed)

Related listings