Chapter Review:

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• Control and coordination are the functions of the nervous system and hormones in our bodies.
• Writing, talking, moving a chair, clapping at the end of a programme are examples of voluntary actions
• The brain has three such major parts or regions, namely the fore-brain, mid-brain and hind-brain.
• The fore-brain is the main thinking part of the brain. It has regions
  which receive sensory impulses from various receptors.
• Many of these involuntary actions are controlled by the mid-brain and hind-brain. All these involuntary actions including blood pressure, salivation and vomiting are controlled by the medulla in the hind-brain.
• When growing plants detect light, a hormone called auxin.
• Gibberellins is plant hormones which help in the growth of the stem.
• Cytokinins is plant hormones  which promote cell division.
• Abscisic acid is plant hormones which inhibits growth. Its effects include wilting of leaves. 
• Chemical coordination is seen in both plants and animals.

Text-book Questions

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Page no. 119

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

Answer: The reflex action is controlled by the spinal cord part of the brain but walking is a deliberate action by the brain. Reflex action involves very little Amy, but in jogging it takes a long time for the information to reach the muscles.

Q2. What happens at the synapse between two neurons?

Answer: Synapse is the small gap between two nerve cells. The nerve impulse coming in the form of electrical waves secretes a chemical which comes in the gap of the empty space, similarly these chemicals reach the next nerve cell by crossing the synapse.

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

Answer: Cerebellum of the posterior brain.

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

Answer: There are some centers in the brain for receiving information in different parts. which are present in the forebrain. There is a wall lobe for smell.

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

Answer: Reflex action is not under the control of brain. Secreted reflex actions are controlled by the spinal cord. The brain collects information about the action that takes place in the reflex action.

Page no. 122

Q1. What are plant hormones?

Answer: Plants secrete some important chemicals from their different parts which control the growth and other activities of plants, they are called plant hormones

Q2. How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?

Answer: The movement of leaves of a mimosa plant is different from the movement of shoots towards light as the movement of light and shoots is a trajectory that is controlled by the oxycin hormone. But touching the leaves of the mimosa plant causes the spreading shrinkage which is not controlled by light.

Q3. Give an example of a plant hormone that promotes growth.

Answer: Occin Hormone.

Q4. How do auxins promote the growth of a tendril around a support?

Answer: Pratan is a sensitive plant, as soon as it comes in contact with any of its shares, water and auxin move in the opposite direction. In this way the cells become elongated and ductile and the protuberance is twisted and wrapped around the base.

Q5. Design an experiment to demonstrate hydrotropism.

Answer: Experiment to show hydrotropism - Take a plant and grow it in a pot, its soil should be wet from one side and dry from other side. After testing it after a few days, we will find that the roots of the plant move towards the aquatic soil, from this design we find that there is a positive hydrotropism in the roots.

Page no. 125 

Q1. How does chemical coordination take place in animals?

Answer: Special glands secrete certain hormones in animals. These hormones do chemical coordination.

Q2. Why is the use of iodised salt advisable?

Answer: Use of iodized salt is recommended because thyroid controls the digestion of carbohydrates, fats and proteins in the body. This gland secretes a hormone called thyroxine. Iodine is required for this gland. Iodine deficiency causes goiter disease

Q3. How does our body respond when adrenaline is secreted into the blood?

Answer: Due to the release of adrenaline in the blood, the heart beats faster, our muscles increase and the respiratory rate also increases.

Q4. Why are some patients of diabetes treated by giving injections of insulin?

Answer: Insulin is needed to control the increased sugar in the blood. This hormone is controlled by it and it is secreted by the pancreatic gland. Its secretion is less in diabetic patients, so the injection of insulin controls the sugar in the blood.

NCERT Solutions Exercise 

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Q1. Which of the following is a plant hormone?

(a) Insulin

(b) Thyroxin

(c) Oestrogen

(d) Cytokinin.

Answer: (d) Cytokinin.

Q2. The gap between two neurons is called a

(a) dendrite.

(b) synapse.

(c) axon.

(d) impulse. 

Answer: (b) synapse.

Q3. The brain is responsible for

(a) thinking.

(b) regulating the heart beat.

(c) balancing the body.

(d) all of the above.

Answer: (d) all of the above.

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

Answer: The receptor is located in the sensitive organs. They receive information from the environment. Through these, the person balances himself with the environment, if they do not work properly, then the brain will not be able to receive information or will delay, so the person will become insecure.

Q5. Draw the structure of a neuron and explain its function.

Answer: Nerve cell (neuron) is the functional and structural unit of the nervous system. It is divided into three parts.

(i) stem, (ii) cell, (iii) axon

Our body has sensory nerves and nerves. The sensory nerve carries the information to the spinal cord after receiving the stimulus from the receptor organs and the information from the carrier brain reaches the organs.

Q6. How does phototropism occur in plants?

Answer: Root responds by turning opposite to light and stem by turning in the direction of light, it is called phototropism. Oxygen hormone is secreted in the plant. It enters the dark part of the stem in the sunlight and the cells there are elongated and they are bent towards the light. This is called positive photoelectricity. Roots indicate negative.

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

Answer: Reversible actions will not be able to complete. Apart from this, not all information will be transmitted properly.

Q8. How does chemical coordination occur in plants?

Answer: Plant cells secrete hormones. These hormones control growth, development and division. These hormones establish chemical coordination.

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

Answer: If the system of control and coordination is not there in the organism, then the cells will not work as per the wishes of the organism. Therefore, it is very important to control them. It is effective for normal functions in multicellular organisms.

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

Answer: Involuntary Actions:

(i) These activities are controlled by the brain - beating of the heart, breathing.

(ii) It takes more linen to complete these activities.

Reversible Actions:

(i) These activities are controlled by the spinal cord. Usage : the withdrawal of the hand on touching a hot object.

(ii) These activities take very less time to complete.

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

Answer: Nervous mechanism of action:

(i) Nervous system receives sensory information and sends its message and controls it.

(ii) The nervous system forms its own network in the body and has its own structural unit.

Reversible Actions:

(i) Hormones are secreted only by important glands in the organs of the body, these hormones control many activities for example - growth, development, reproduction etc.

(ii) Hormones themselves are secreted in the body.

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 Mimosa Plants:

(i) The basis of motion in this plant is touch.

(ii) Here the motion is based on the bending and blooming of the husbands.

(iii) Here the size of the leaves also changes.

Speed of our leg:

(i) The basis of motion in this is the human nervous system.

(ii) Here the motion is based on the contraction and expansion of the muscles.

(iii) There is no change in the size of the foot or its muscles.

Chapter-7. Control and Coordination

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Q – what is dendrite ? Write its function.

A – specialised edges of neuron is called dendrite.

 Function of Dendrite;

(i)It recieves all informations.

Q – What is called the space between two neurons?

A – Synapse.

Q: Name the two substances which are responsible for the control and coordination in plants.

Ans: phytohormones.  

Q – write the function of sensory nerves?

A – It receives information from sensory organs.

Q – Write the function of motor nerves.

A – It sends impulses to muscles to take actions.

Q – How do informations travel into neurons?

A – Informations travel as electric impulse.

Q – What is the scientific name of following receptors in an animal?

(a)Receptors for light

(b)Receptors for sound

(c)Receptors for taste

(d)Receptors for Heat.

(e)Receptors for smell.

A –

(a)Photo receptor

(b)Phono receptor

(c)Gustatory receptor

(d)Thermo receptor

(e)Olfactory receptor.

Q – Write difference between involuntary actions and reflex actions.

A –

involuntary actions	reflex actions
1.It is a set of muscle movement over which we do not have thinking control. 2.It is controlled by brain. 3.Examples: Beating of heart, respiration, etc.	1.it is rapid, spontaneous and involuntary activity that is produced in response to as stimulus. 2.It is controlled by spinal cord. 3.Removal of hand from hot object.

Q – What is reflex arc?

A – The pathway of reflex action is termed as reflex arc. When we touch a hot object the stimulus passes through sensory nerve to spinal cord. From here the motor nerve brings the message to the musles of hand to contract and hand is removed within a fraction of time from the hot object.

Q – Which organs forms central nervous system?

A – Brain and spinal cord.

Q – What is called that bone box which protects the brain?

A – Cranium.

Q – What is called the membrane which provides protection to the brain?

A – Menings.

Q – What is C.S.F? Write its function?

A –  Full name of C.S.F is Cerebro spinal Fluid. It is a fluid which found among three Menings. It prevents brain to Meningitis and internal injuries.

Q – Name the parts of hind-brain and mention their functions.

A – The hind-brain consists of three centers:

(i)Cerebellum – It maintains posture and adjusts movement.

(ii)Pons – It takes part in regulation of respiration.

(iii)Medulla oblongata – it is regulating center for swallowing, coughing, sneezing and vomiting. 

(i)Fore-brain –

(ii)Mid-brain – it controls the involuntary actions of body.

(iii)Hind-brain – It even controls the the involuntary actions of body. And all involuntary actions like blood pressure, salivary secretion and vomiting are controlled by medulla oblongata situated in hind-brain.

Q – Name the part of brain which is responsible for precision of voluntary actions and maintaining the posture and balance of the body.

A – cerebellum.

Q – Distinguish between Positive geotropisms and negative geotropisms.

A –

Positive geotropisms	Negative geotropisms
If the parts of plant grow toward the direction of gravity. It is called Positive geotropisms. Example: roots show positive geotropism.	If the parts of plant grow opposite the direction of gravity. It is called negative geotropisms. Example: stems show negative geotropism.

 

Q – What is phyto hormones (plant hormome)?

A – Phyto hormones are the substances which are responsible for coordinate and control in plants. These are five in number.

(i) Auxins –

(a) It is responsible for enlongation of plants.

(b) It enhances the growth of fruits.

(c) It enhances the growth of cell and cell division. 

(d) Auxin also influences rooting formations.

(ii)Gibberllin –

(a)  Gibberllin enhances the growth of cell and cell division in presence of Auxin

(b)  It enhaces the growth of fruits and stems.

(c) Gibberllin also enhances the transition to flowering, and the development of flowers, fruits, and seeds 

(iii) Cytokinins

(a) It stimulates the cell division in plants.

(b) It helps in blooming of fruits.

(iv) Abscisic Acid

(a)  It inhibits and controls the growth of plants.

(b)  It controls the water loss in plants.

(c)  It encourages the protein synthesis in plants.

(v)Athelin

(a) It promotes fruits for ripping.

(b) It increases the numbers of female flowers.

(c)  It helps in growth of stems.

Ques: What are glands? write it type.

Ans: Glands: Glands are the body organs which secretes hormones.

There are two types of glands.

(1)Endocrine glands: The glands which secretes their hormones directly through blood stream. Ex. Pituitary gland, thyroid gland, thymus gland etc.

(2)Exocrine glands: The glands which secretes their hormones through the duct. Ex. Liver, Lachrymal, Mammary gland etc. 

Questions for practice: 

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Q1. Name the two substances which are responsible for the control and coordination in plants.

Q2. What are Phytohormones? Name any two.

Q3. What is the difference between photoperiodism and phototropism?

Q4. What are nastic movements? Give one example.

Q5. What are the different Hormones found in Plants and their functions?

Q6. What are receptors? What type of receptors detects smell and taste?

Q7. How the information is send to brain in animals?

Q8. What is cranium?

Q9. How are tissues protected in a brain?

Q10. What is role of brain in reflex action?

Q11. What happens at the synapse between two neurons?

Q12. What is stimulus?

Q13. What are the different types of nervous systems found in human body? Mention the functions of each.

Q14. Draw the schematic diagram of reflex arc. Define reflex action with suitable example.

Q15. Draw the labeled structure of human brain.

Q16. What are the four main parts of the fore brain? Give the function of each part.

Q17. What are the three parts of the mid brain and their functions?

Q18. Which part of the human brain is responsible for: Intelligence and Memory, Adjustment movement and Posture, Smell?

Q19. Give the role of Frontal lobe, temporal, lobe and medulla oblongata.

Q20. Name the different lobes found in the fore brain and give their functions.

Q21. What is geotropism?

Q22. What are plant hormones?

Q23. What are controlled movements? How this process happens?

Q24. What are electrical impulses? What re its limitations?

Q25. How the stimulated cells overcome the limitations of electrical impulses?

Q26. How do auxins promote the growth of a tendril around a support?

Q27. Which hormone is responsible for the wilting of leaves in plants?

Q28. What are hormones? Who coined the term hormones?

Q29. What is function of adrenaline? Explain briefly?

Q30. Why diabetes is happen? What is insulin?

Q31. Draw the diagram showing endocrine glands in a male body/female body and label: Pituitary, Thyroid, Adrenal, Testis/ovaries, Thalamus, and Hypothalamus.

Q32. Name the hormone associated with a) Reduction of blood glucose in the body b) Overall metabolism of the body.

Q33. Write the function of testes & ovaries.

Q34. What is function of pituitary gland?

Q35. What is need of control and coordination in the body?

Q36. Which is the structural and functional unit of nervous system? Describe with the help of a diagram.

Q37. “Nervous and the hormonal system together perform the function of the control and coordination in the humans”. Justify.