NCERT solution for class 10th // Science // Chapter 7 - Control and coordination

 NCERT solution >  Class 10 >  Science  


NCERT solution for class 10th //  Science  // Chapter 7  -  Control and coordination

                Page number - 119

Q1. What is the difference between a reflex action and walking ? 

Answer-   The difference between a reflex action and walking are as follows .

Reflex action .

  • It is an spontaneous and involuntary response to a stimulus .
  • It is regulated by spinal cord .
  • Its intensity cannot be changed 
  •  It Increases the survival and protective values of an organism 

Walking 

  • It is acquired through learning and it is a voluntary response 
  • It is  coordinated by the brain 
  • Its intensity can be changed 
  • It is connected with the  locomotion

Q2. What happens at the synapse between two Neurons? 

Answer- Synapse is a connection between the  two neurons it is a small gap between two neurons at the end of axon the electrical impulse are release of some chemicals in a form of neurotransmitter which move from that gap and start the similar electrical impulse to the dendrites of next neuron it is a one way valve

Q3. Which part of the brain maintains posture and equilibrium of the body ? 

Answer - The part of hind brain that is cerebellum is maintenance the posture and equilibrium of the body

Q4. How do we detect the smell of an agarbatti (incense stick) ?

Answer- The smell of incense stick is identify the neuron of olfactory receptors of nose with generate the nerve impulses that reach the olfactory lobe of the fore brain and produce the sensation of smell

Q5. What is the role of the brain in reflex action? 

Answer- Reflex action is carried out by the spinal cord that has no role of brain in reflex action it is a quick reaction which does not involve any thinking by the brain the stimulus is received by the spinal cord that sends the response  

Example - Sensation of body towards the cold and hot conditions, coughing ,sneezing etc

                        Page number 122. 

Q6. What are plant hormones ? 

Answer - Plant hormones are the organic substance naturally produced in higher plants and these are helpful to control the growth and physiological function of plant these are required in very small quantity

Q7. How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light? 

Answer- . Movement of leaves is independent of growth it is not directional and neither away or towards the stimulus

Movement of shoot is dependent on growth it is stimulus to light directional and movement towards the stimulus

Q8. Give an example of a plant hormone that promotes growth? 

Answer- Auxin is a plant hormone which promotes the growth in plants

Q9. How do auxin promote the growth of a tendril around a support? 

Answer- Auxin is a growth hormone which is responsible for cell division and elongation at the tissue tip the tendril comes in contact with support . Auxin stimulates faster and growth of the cells increases in opposite sides and tendril coils around the support

Q10. Design an experiment to demonstrate hydrotropism? 

Answer- The growth of the plant parts towards or away from the water is called hydrotropism 



For experiment to take a plant in a jar filled with sand place the porous pot filled with the water in a wide jar roots of the plants will grow towards the water and Bane towards the water sources showing the positively hydrotropism

                    Page number 125. 

Q11. How does chemical coordination take place in animals ? 

Answer- Chemical coordination take place in animals with the help of hormones secreted by endocrine glands these are the chemical messengers which are initiate the activities of the living organism and their growth the timing and amount of hormones released are regulated by the feedback mechanism

Q12. Why is the use of iodised salt advisable? 

Answer- Iodized salt in diet is advisable because iodine is a minerals which is essential for the synthesis of thyroxine hormone and if it is insufficient in diet it  may be a possibility of suffering from goitre

Q13. How does our body respond when adrenaline is secreted into  the blood? 

Answer- Adrenaline is called the emergency hormone it is secreted by the adrenal gland into the blood and it carried out to different parts of the body at the time of emergency or stress example- during exercise it causes fast beating of heart resulting in the supply of more oxygen to muscles

Q14. Why are some patient of diabetes treated by giving injections of insulin? 

Answer- Insulin is the hormone secreted by pancreas help to regulate the blood sugar level in body if sugar level increases in blood due to lack of insulin then it causes many harmful effects so some diabetic patient given the injections of insulin to fulfill their requirement of insulin in the body

                            Exercise 

Q1. Which of the following is a plant hormone 

a) Insulin  b) Thyroxine. c)  Oestrogen d) Cytokinin  

Answer - Cytokinin

Q2. Gap between two neurons is called a 

a) Dendrites      b) Synapse.   c) Axon.    d) Impulse 

Answer-  Synapse

Q3. The brain is responsible for 

a) Thinking b)  Regulating the heartbeat c) Balance in the body   d) All of the above  

Answer -   All of the above 

Q4. What is the function of receptors in our body think of situations where receptors do not work properly what problem are likely to arise ?

Answer- Receptors in our body collect the all information about the changes in the environment around us and pass the same information in the form of nerve impulse to the central nervous system where the information is processed and ultimate response is given

Q5. Draw the structure of the nerve cell and explain its functions 

Answer-  



Functions of neuron

Neurons receive the information from the receptors in the form of electrical impulse and transmit it towards the central nervous system by sensory neuron . It also collect the rivers information by motor neuron from central nervous system to the affected  organ

Q6. How does phototropism occur in plants ?

Answer- The directional movement of the plant in response to light is called phototropism the shoots are positively phototropic while the roots are negatively phototrophic for the growth of the plant towards the source of light auxin hormone is responsible for it

Q7. Which signals will get disrupted in case of a spinal cord injury ? 

Answer- In spinal cord injuries the signals for reflex actions and involuntary actions will get disrupted.

Q8. How does chemical coordination occur in plants ?

Answer- Chemical coordination occur in plants by the plant hormone plant hormone are the chemical compound which help in the coordination of the growth in plants and response to the environment 

  • Auxin help in cell initiation and elongation 
  • Gibberellin help in growth of the stem .
  • Abscisic acid inhibit the plant growth 
  • Cytokinins promotes the cell division

Q9. What is the need for a system of control and coordination in an organism ? 

Answer- All the organisms need well organised system of control and coordination because it is the characteristics property of all living beings the body respond in a manner that the most appropriate for its survival and functioning it is very necessary that all the organs work together in a proper coordinated way so that it provide the correct response working together of various organs in the systematic order provide proper control and respond to stimulus is called coordination

Q10 . How are involuntary actions and reflex actions different from each other ? 

Answer- The involuntary actions and reflex actions are different from each other in following ways 

Involuntary actions 

  • They involve The automatic nervous system 
  •  involuntary actions involving functioning on the internal body parts 
  • The nervous system controlling involuntary actions has two division sympathetic and parasympathetic 
  • Sometimes gap occurs between the stimulus and response 
  • Most of the involuntary functions occurs all the time 
  • Example  - Process of respiration , blinking of eyes

Reflex actions  

  • The involves all parts of voluntary and nervous system they are not under our control .
  • Reflex action are concerned with emergency 
  • The commonly operate against harmful stimuli which are generally external 
  • Reflex action does not have any division 
  • It is occurs occasionally 
  • They are performed by the striated muscles 
  • Example- keep the hand back when someone pick the needle


Q11. Compare and contrast nervous and hormonal mechanism for control and coordination in animals? 

Answer-

Hormonal control and coordination in animals 

  • It is through chemicals called hormones 
  • This system is completely slower .
  • This system not connected to target site directly 
  • This system control growth and development 
  • It consists of glands and their secretion 
  • Effect of the hormones last for longer period . 
  • It is involuntary 

Nervous mechanism 

  • It is through electrical conduction 
  • This is a rapid system 
  • It is directly connected to the every part under its control . 
  • This response are quick and limited to those sales which are invented with nerves 
  • It has a very little role in growth and development 
  • The effect of nervous action is for very short duration 
  • It can be voluntary or involuntary

Q12. What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs ?  

Answer-  

Movement in sensitive plant 

  • In sensitive plant the response to the external stimulus like touch 
  • Plant cells change their shape due to changing the amount of water in them 
  • No nerves are involved there 

Movement in legs 

  • It is the voluntary action performed by the controlled of our will 
  • Movement of legs is the voluntary action it is controlled by the cerebellum part of the hind brain 
  • Nurse carries the message for the movement of legs.

Comments

Post a Comment

Text

Popular posts from this blog

NCERT solution for class 6 || Science || Chapter 13 - Fun with magnets

  NCERT solution > class 6 > Science  Chapter 13 - Fun with magnets  Exercise  Q1. Fill in the blanks in the following.  i) Artificial magnet are made in different shapes such as  H orse shoe and cylindrical ii) The materials which are attracted towards a magnet are called Magnetic materials  iii) Paper is not Magnetic material . iv) In olden days sailor used to find direction by suspending a piece of Magnet   v) A magnet always has Two poles.  Q2. State whether the following statements are true or false  i) Cylindical magnet has only one pole  ii) Artificial magnets were discovered in Greece . iii) Similar poles of a magnet repel each other . iv) Maximum iron filings stick in the middle of the bar magnet when it is brought them near.  v) Bar magnets always point towards north south direction. vi) Compass can be used to find east west direction at any place . vii) Rubber is a magnetic material . Answer - i) fals...
Read more

NCERT Solution //class 8// Science // Chapter 8- Cell structure and functions

Image
NCERT solutions of class 8 >Science > Chapter 8 - Cell structure and functions  NCERT Solution //class 8// Science // Chapter 8-  Cell structure and functions 1 .   Indicate whether the following statements are true or false a)  Unicellular organisms have one -celled body.     Answer. - True b) Muscle cells are branched Answer. -True c) The basic living unit of an organism is an organ Answe r-. False d) Amoeba has irregular shape Answer . True   2. Make a sketch of human nerve cell what function do nerve cell perform?  Answer .        Function of nerve cells-  Nerve cell carry the signal of sensation from different body parts to brain or  it again carry the reverse signal from brain to other body parts. 3. Write a short notes on following  a) Cytoplasm -             The space present between the nuclear membrane and plasma membrane is filled with the translucent ...
Read more

NCERT solution for class 6 || science || chapter 14 - Water

 NCERT solutions>  Class 6 > Science  NCERT solution for class 6 || science || chapter 14 -  Water Chapter 14 -Water   Exercise  Q1. Fill up  the blanks in the following  a) The process of changing of water into its vapour is called evaporation b) The process of changing water vapour into water is called condensation  c) No rainfall for a year or more may lead to drought in that region . d) Excessive rain may cause floods . Q2. State for each of the following whether it is  due to evaporation or condensation  . a) Water drops appear on the outer surface of  a glass containing cold water. b) Steam rising from wet clothes while they are iron  c) Fog appearing on a cold winter morning  d) Blackboard dries up after wiping it  e) Steam rising from ala hot girdle when water is sprinkled on it . Answer -  a) Condensation  b) Evaporation  c) Condensation  d) Evaporation  e) Evaporati...
Read more