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BY : ARUNGOBIND YUMNAM, EXAMINER & CO-ORDINATOR OF BOSEM, 56th position, all India 2nd position of Manipur, AITTARI,, , NON TEXUAL QUESTION AND ANSWER FOR CLASS X BIOLOGY, CHAPTER-14 (CONTROL & CO-ORDINATION), Q1. Which plant hormone is responsible for the wilting and falling of leaves ?, Ans :Abscisic acid is responsible for the wilting and falling of leaves in plants., Q2. Which plant hormone makes a stem (or shoot) bend towards light ?, Ans :Auxin., Q3. Where is the auxin hormone made in a plant stem ?, Ans :Auxin is made at the tip of the plant stem., Q4. Name one plant hormone that promotes growth and another plant hormone which inhibits, growth., Ans :A plant hormone that promotes growth is Gibberellin and the hormone that inhibits growth is, abscisic acid., Q5. What are the two parts of the vertebrate nervous system ?, Ans :Central nervous system and Peripheral nervous system., Q6. If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is, this type of action known as ?, Ans : Reflex action., Q7. Name the three components of a neuron (or nerve cell)., Ans : Cell body, dendrites and axon., Q8. Name the most important part of the human brain., Ans : Cerebrum., Q9. Which part of the brain maintains posture and balance of the body ?, Ans : Cerebellum., Q10. Name one hormone secreted by the pituitary gland., Ans : Growth hormone., Q11. Where are hormones made in the human body ?, Ans : Endocrine glands., Q12. Name the hormones secreted by (a) testes, and (b) ovaries, Ans :, (a) Testosterone., (b) Oestrogen., Q13. What are the scientific names for the following receptors in animals ?, (a) receptors for smell, (b) receptors for taste, Ans :, (a) Olfactory receptors., (b) Gustatory receptors., Q14. Name the disease caused by the deficiency of insulin hormone in the body., Ans : Diabetes., Q15. Name the disease caused by the deficiency of thyroxine hormone in the body., Ans : Goitre., Q16. Which halogen element is necessary for the making of thyroxine hormone by the thyroid, gland ?, Ans : Iodine., Q17. Why are some patients of diabetes treated by giving injections of insulin ?, Ans : The people having severe diabetes are treated by giving injections of insulin., 1
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Q18. Name one gland each :, (a) which acts only as an endocrine gland., (b) which acts only as an exocrine gland., (c) which acts both as an endocrine gland as well as an gxocrine gland., Ans :, (a) Thyroid gland., (b) Salivary glands., (c) Pancreas., Q19. What part does the diet play in helping us to have a healthy thyroid gland ?, Ans : Diet provides iodine for making thyroxine hormone which keeps the thyroid gland healthy., Q20. If sugar is detected in the urine of a person, name the disease he is suffering from., Ans : Diabetes., Q21. Which parts of the body form the central nervous system ?, Ans : Brain and spinal cord., Q22. Why do you need iodine in your diet ?, Ans : Because iodine is necessary for making thyroxine hormone., Q23. What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d), hydrotropism? (e) thigmotropism ?, Ans :, (a) Light., (b) Gravity., (c) Chemical., (d) Water., (e) Touch., Q24. Give the scientific terms used to represent the following :, (a) Bending of a shoot towards light., (b) Growing of roots towards the earth., (c) Growth of a pollen tube towards ovule., (d) Bending of roots towards water., (e) Winding of tendril around a support, Ans :, (a) Phototropism., (b) Geotropism., (c) Chemotropism., (d) Hydrotropism., (e) Thigmotropism., Q25. Give one example each of a plant part:, (a) which is positively hydrotropic as well as positively geotropic., (b) which is positively phototropic but negatively geotropic., Ans :, (a) Root., (b) Stem., Q26. What is a plant hormone ? Name four plant hormones. State one function of each., Ans :, The hormones that control and coordinate the activities in plants are called plant hormones. The, four types of plant hormones are:, (i) Auxins – It promotes cell enlargement and cell differentiation in plants., (ii) Gibberellines – It helps in breaking the dormancy in seeds and buds., (iii) Cytokinins – It promotes cell division in plants., (iv) Abscisic acid – It promotes the dormancy in seeds and buds., 2
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Q27. (a) What does a root do in response to gravity ? What is this phenomenon known as ?, (b) What does a stem (or shoot) do in response to light ? What is this phenomenon known as ?, Ans :, (a) Root bends downwards in the direction of gravity; positive geotropism., (b) Stem bends towards the light; positive phototropism., Q28. Distinguish between tropic movements and nastic movements in plants. Give examples to, illustrate your answer., Answer :, Tropic movements, 1. These movements are always in the direction of the stimulus., 2. These movements are slow., 3. These movements are exhibited by all parts of a plant. For example, movement of shoot towards, the light and not towards gravity., Nastic movements, 1. These movements are neither away nor towards the stimulus., 2. These movements are fast., 3. These movements are exhibited by the flat organs (like leaves and petals of flowers) of a plant., For example, the bending and drooping of leaves in ‘Touch-me-not’ plant., Q29. Name the plant hormones which are responsible for the following effects :, (a) falling of leaves, (b) opening of stomata, (c) bending of stem towards light (d) closing of stomata, Ans :, (a) Abscisic Acid, (b) Cytokinin, (c) Auxin, (d) Abscisic Acid, Q30. (a) What is meant by ‘tropisms’ (or tropic movements) ? Explain with an example., (b) What are the different types of tropisms ? Define each type of tropism. Write the, name of stimulus in each case., Ans :, (a) A growth movement ofa plant part in response to an external stimulus in which the direction of, stimulus determines the direction of response is called tropism. Example – The bending of plant, stem towards light is an example of positive phototropism., (b) Different types of tropisms are:, (i) Phototropism – The movement of a plant part in response to light is called phototropism. Its, stimulus is light., (ii) Geotropism – The movement of a plant part in response to gravity is called geotropism. Its, stimulus is gravity., (iii) Chemotropism – The movement of a plant part in response to a chemical stimulus is called, chemotropism. Its stimulus is chemical., (iv) Hydrotropism – The movement of a plant part in response to a water stimulus is called, hydrotropism. Its stimulus is water., (v) Thigmotropism – The movement of a plant part in response to a touch stimulus is called, thigmotropism. Its stimulus is touch., Q31. (a) Define phototropism. Give one example of phototropism., (b) How does phototropism occur in a plant stem (or shoot) ? Explain with the help of, labelled diagrams., Ans :, (a) Phototropism – The movement of a plant part in response to light is called phototropism., Example -Stem bends towards the light is positive phototropism., (b) Phototropism in a plant stem – The bending of a plant stem towards light is an example of, 3
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phototropism. The plant stem responds to light and bends towards it due to the action of auxin, hormone. The auxin hormone is present at the tip of the stem of the growing plant. Auxin prefers to, stay in shade away from light so when sunlight falls on the stem from one side, it gets concentrated, on the opposite side. Due to more auxin, the shady side of the stem grows to be longer than the side, of stem which is facing light, and makes the stem bend towards light., , Q32. (a) How does control and coordination take place in plants ? How does it differ from that in, animals?, (b)Name five stimuli which act on plants. Name the type of tropism produced by each one of, these stimuli., (c) Define hydrotropism. Give one example of hydrotropism. State whether this example, is of positive hydrotropism or negative hydrotropism. Illustrate your answer with the, help of labeled diagram., Ans :, (a) The plants do not have a nervous system but they can sense things in the presence of stimuli, such as light, touch, water etc. and respond to them by the action of hormones. Thus, the plants, coordinate their behavior against environmental behavior by using organic chemicals called, hormones. This is called chemical coordination. The hormones in plants coordinate their behavior, by affecting the growth of a part of the plant resulting in the movement of that plant part in, response to a stimulus. The control and coordination in animals takes place by both nervous, system and hormones., (b), (i) Light – Phototropism., (ii) Gravity – Geotropism., (iii) Chemical – Chemotropism., (iv) Water – Hydrotropism., (v) Touch – Thigmotropism., (c) The movement of a plant part in response to water is called hydrotropism. Example: The roots, of a plant always go towards water, this is positive hydrotropism., , Q33. Give the functions of medulla., Ans :The medulla controls various involuntary actions such as heart beat, breathing, blood pressure and, peristaltic movements of the elementary canal., It is also the controlling centre for reflexes such a swallowing, coughing, sneezing, secretion of, saliva and vomiting., 4
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Q34. What is the function of receptors in our body ?, Ans : Receptors are the special cells present in our sense organs which detect all the information from, our environment and feed it to the nervous system., Q35., (a) Name the hormones secreted by the following endocrine glands :, (i) Thyroid gland (ii) Parathyroid glands (iii) Pancreas (iv) Adrenal glands, (b) Write the functions of testosterone and oestrogen hormones., Ans :, (a), (i) Thyroxine, (ii) Parathromone, (iii) Insulin, (iv) Adrenaline., (b) The function of testosterone hormone is to control the development of male sex organs and, male features such as deeper voice, moustache, body hairs etc. The function of oestrogen is to, control the development of female sex organs and female features such as feminine voice, soft skin, and mammary glands., Q36. Name the functions of cerebrum., Ans :, Function of cerebrum: It is the main thinking part of the brain. It is the site of our faculties such as, learning, reasoning, intelligence, personality and memory. All our thoughts, sensation, actions and, movements are controlled by cerebrum., Q37. (a) The human brain can be broadly divided into three regions. Name these three regions., (b) What is cranium ? What is its function ?, Ans :, (a) The 3 regions of human brain are, (i) Forebrain, (ii) Midbrain and, (iii) Hindbrain., (b) Cranium is a bony box in the skull in which the brain is present. Its function is to protect the, brain., Q38., (a) How does chemical coordination take place in human beings ?, (b) Why is the use of iodised salt advisable ?, Ans :, (a) The chemical coordination in animals takes place through the actions of chemicals called, hormones which are release directly into the blood and are carried by the blood circulatory system, to other parts of the body. Hormones travel all over the body but affect only particular organs at, particular places which are called target organs. The organs control and coordinate several, functions of animal body such as growth, development, metabolism, behavior and secondary sexual, characteristics, etc., (b) Iodine is necessary for the thyroid gland to make thyroxine hormone which regulates the, metabolism of carbohydrates, fats and proteins so as to produce the best balance for the growth., Iodised salt is advisable as it contains appropriate amounts of iodine compounds needed by the, thyroid gland to make sufficient thyroxine hormone for the body and hence goitre disease can be, prevented., , Q39.What is the function of insulin hormone ? What type of patients are given insulin injections ?, Ans : The function of insulin hormone is to lower the blood sugar level (or blood glucose level)., People having severe diabetes are treated by giving injections of insulin., , 5
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Q40. State the functions of the following hormones :, (a) Thyroxine (b) Adrenaline (c) Growth hormone, Ans :, (a) Thyroxine: The function of this hormone is to control the rate of metabolism of carbohydrates,, fats and proteins in the body., (b) Adrenaline: Its function is to regulate heart rate, breathing rate, blood pressure and, carbohydrate metabolism., (c) Growth hormone: It controls the growth of the human body., Q41. A person walks across a room in barefeet and puts his foot on a drawing pin lying on the, floor. He lets out a cry. Explain what happens in his nervous system in bringing about this, response., Ans : It is an example of reflex action. The stimulus here is drawing pin lying on the floor. The pain is, sensed by the receptors in the skin which triggers and impulse in a sensory neuron and transmits the, message to the spinal cord. The impulse is passed onto a relay neuron, which in turn, passes it to the, motor neuron. The motor neuron passes the impulse to a muscle in the feet. The muscle then contracts, and pulls our feet away from the drawing pin., Q42. Explain the difference between cerebrum and cerebellum, Ans :, Cerebrum, (i) It is a part of forebrain., (ii) It is the main thinking part of the brain. All our thoughts, sensation, actions and movements are, controlled by cerebrum., Cerebellum, (i) It is a part of hindbrain., (ii) It helps in maintaining posture and balance of the body. It enables us to make precise and, accurate movements., Q45. What is the difference between a voluntary and an involuntary action ?, Ans :, , Q46. Which hormone :, (a) prepares the body for action ?, (b) controls the amount of glucose in blood ?, (c) gives boys a deep voice ?, (d) gives girls soft skin ?, Ans :, (a) Adrenaline., (b) Insulin., (c) Testosterone., (d) Oestrogen., Q47., (a) What is a reflex action ? Explain with the help of an example., (b) Define reflex arc. Give the flow chart of a spinal reflex arc., 6
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(c) How are involuntary actions and reflex actions different from each other ?, Ans :, (a) The rapid, automatic response to a stimulus which is not under the voluntary action of the brain is, called reflex action.Example: Moving our hand away on touching a hot plate., , Q48., (a) What is a neuron ? Draw a labelled diagram of a neuron., (b) What is a synapse ? What happens at the synapse between two neurons ?, Answer :, (a) The unit which makes up the nervous system is called a neuron., , 7
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(b) A microscopic gap between a pair of adjacent neurons over which nerve impulses pass when, , going from one neuron to the next is called a synapse. Synapse between two neurons acts as a one way, valve which allows electrical impulses to pass in one direction only., , Q49. Give the various functions of brain., Ans :, (i) The brain receives information carrying nerve impulses from all the sensory organs of the body., (ii) It responds to the impulses brought in by sensory organs by sending its own instructions, through motor nerves to the muscles and glands causing them to function accordingly., (iii) It correlates the various stimuli from different sense organs and produces the most, appropriate and intelligent response., (iv) It coordinates the body activities so that the mechanisms and chemical reactions of the body, work together efficiently., (v) It stores information so that behavior can be modified according to the past experience., Q50., (a) Write the names of five endocrine glands found in the human body. Name the, hormones secreted by each gland., (b) How do hormones reach the organs they control ?, (c) How does our body respond when adrenaline is secreted in large amounts into the blood ?, (d) Name the disease which occurs in adults due to the deficiency of iodine in the diet., What is the main symptom of this disease ?, Ans :, (a), (i) Pituitary – Growth., (ii) Thyroid – Thyroxine., (iii) Pancreas – Insulin., (iv) Adrenal – Adrenaline., (v) Testes – Testosterone., (b) The endocrine glands do not have ducts to secrete their hormones. They release hormones, directly into the blood of a person and reach the concerned body part through the blood and act on it., (c) The adrenaline hormone prepares our body to function at maximum efficiency during, emergency situations like danger, anger etc. This adrenaline hormone increases our heartbeat,, breathing rate, blood flow into muscles and causes liver to put more stored glucose into our blood., All these actions produce a lot of energy in our body and help us to cope up the emergency, situations. Thus, when adrenaline is secreted in large amounts it prepares our body for action., (d) Goitre – The neck of the person appears to be swollen due to the enlargement of thyroid gland, located in the neck., , TEXUAL QUESTIONS AND ANSWERS, Let us answer (page no. - 279), Q1. What is a reflex action?, Ans: An involuntary sudden, spontaneous response to a stimulus controlled by spinal cord is called a, reflex action., Q2. What happens at the synapse between two neurons?, Ans: The transmission of electrical impulse between two neurons takes place through the synapse. When, such an impulse reaches the nerve endings, it sets off the release of chemicals called neurotransmitters at, the synapse that cross the gap and bind to the dendrite of the next neuron and start a similar nerve, impulse., , 8
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Q3. Why should we use iodised salt?, Ans: Iodine is needed by the thyroid gland for the synthesis of thyroxine hormone. The deficiency of, iodine causes goitre characterized by swollen neck in the absence of thyroxine. Therefore iodized salts are, recommended in our diet in order to prevent from goitre (due to enlargement of thyroid gland)., Q4. Why are some patients of diabetes treated by giving injections of insulin?, Ans: The blood sugar level is high in some diabetic patients due to inadequate secretion of insulin by, pancreas. Insulin converts excess sugar present in blood into glycogen. Thus, some patients are given, insulin to control their normal blood sugar level., Let us answer (page no. 283), Q1. What is the factor responsible for the movement of leaves in the sensitive plants?, Ans: The movement in the leaves of sensitive plant occurs without involving any growth due to changes in, turgor pressure or shape of specialized cells., Q2. What are plant hormones?, Ans: Plant hormones are organic substances which are synthesized in minute quantities in one part of the, plant body and transported to another part where they influence specific physiological processes., Q3. How do auxins promote the growth of tendril around a support?, Ans: When tendrils come in contact with the support, the side away from the support grows faster due to, higher concentration of auxin than the side which is in contact with the support. Such a slow growth, movement is an example of plant response induced by the stimulus of touch (Thigmotropism). Thus, the, unequal distribution of auxin is responsible for growth of tendril encircling around the support., Q4. Give an example of Chemotropism., Ans: The growth of pollen tube through stigma and style towards ovule is an example of chemotropism, induced by chemicals present inside ovary., , TEXTUAL EXERCISE, Q1. How does Phototropism occur in plants?, Ans: The growth of the stem towards unilateral stimulus of light is known as phototropism which occurs, due to the action of auxin which is synthesized at the shoot tip that diffuses towards the dark side of the, stem. The higher concentration of auxin stimulates the cells to grow longer on the dark side of the shoot, than the light side leading to its bending towards light., Q2. Why do roots grow towards the soil? Explain with three points., Ans: The growth movements in response to gravity are called geotropism., Roots grow vertically downwards due to gravitational pull., Primary roots grow down to the soil are positive geotropic and negative phototropic. The concentration of, auxin stimulatory for stem growth is inhibitory in case of roots., Q3. Explain the function of two growth inhibitors in plants., Ans: Abscisic acid (ABA): Abscisic acid is a powerful growth inhibitor which can induce dormancy of bud, and seed. (It also promotes abscission or leaf fall)., Ethylene: Ethylene inhibits longitudinal elongation of stem and roots., Q4. In what way auxin is involved in the process of apical dominance?, Ans: The phenomenon in which intact apical buds suppress the growth of lateral buds is known as apical, dominance. The chemical responsible is the auxin produced in the apical bud and it is due to downward, transport of auxin produced in the apical meristem., Q5. What is the name of the gap between the two neurons?, Ans: Synapse is the gap between two neurons., , 9
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Q6. What is the function of receptors in our body? What will be the conditions if the receptors are, not properly working?, Ans: The receptors present in our sense organs detect stimuli, which are then passed to the CNS in the, form of nerve impulses. The messages are interpreted and instructions are sent to the effectors to produce, responses. If the receptors are not working properly, animals fail to detect stimuli and cannot respond, properly., Q7. How do the reflex actions differ from the involuntary actions?, Ans: Reflex actions are the sudden, spontaneous involuntary actions whereas involuntary actions are, those that cannot be controlled easily by thinking about it., Reflex actions are controlled by spinal cord whereas involuntary actions are controlled by medulla, oblongata of hind brain. Blinking of eyes is an example of reflex action while breathing rate, heart beat etc., are examples of involuntary actions., Q8. Explain the functions of any three hormones in human being., Ans: NAME OF GLAND, TYPE OF HORMONE, FUNCTION OF, HORMONE, Pituitary Gland, Growth hormone, It controls overall, growth of the body; over, secretion causes, gigantism (giant); and, under secretion during, childhood causes, dwarfism (dwarf)., Thyroid Gland, Thyroxine, It controls carbohydrate,, protein and fat, metabolism for growth;, Deficiency of iodine in, our diet causes goitre, characterized by swollen, neck., Pancreas, Insulin, It regulates normal, blood glucose level;, deficiency of insulin, causes high blood, glucose level leading to, Diabetes, , 10
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\Previous Yearly Questions (2010-2020), 2010, 1. Draw a diagram of human neuron and label axon and dendrites., 2. Describe the three types of trophic movement in plants., , 2, 3, , 2011, 1. What is reflex action?, 2. How adrenalines facilitate the animal body to face with hard situation? Give three points., , 1, 3, , 2012, 1. Draw a diagram of nerve cell and label dendrite and axon., , 2, , 2013, 1. State two functions of hind brain of human beings., 2. Explain the action of two growth inhibitors in plants., , 2, 2, , 2014, 1. Explain five functions of hormones in human being., , 5, , 2015, 1. Give one point of difference between Gibberellins and Abscisic acid., 1, 2. Give two effects of difficiency of iodine in the body., 2, 3. What could be the consequences if the adrenal gland is removed from the human body? Give three points.3, , 2016, 1. Cite one function each of cytokinins and ethylene., , 1, , 2017, 1. Which part of the brain controls involuntary action like heart beat, respiration etc?, 2. Give two effects of failure of secretion of insulin in our body., , 1, 2, , 2018, 1. Define apical dominance., 2. Give two functions of adrenaline., 3. Draw a neat diagram of a neuron and label axon and dendrite., , 1, 2, 2, , 2019, 1. What is reflex action?, 2. Which organ is called the gustatory organ ?, 3. Name the hormones responsible for the puberty in males and female., , 1, 1, 1+1=2, , 2020, 1. Describe the functions of Cytokinins and Ethylene as plant hormones., 2. Draw a neat diagram of a neuron and label Dendrite and Axon., , 2, 2, , 2021, Exam. Cancel Due To Covid 19, , 11