Negative feedback mechanisms counteract changes from a set point, bringing the system back to equilibrium (e.g., blood glucose regulation), thus maintaining homeostasis. Positive feedback mechanisms amplify the original change, moving the system further away from equilibrium (e.g., childbirth contractions), and are less common for routine homeostatic control.
More Questions on Control and Coordination
1Imagine a scenario where the hypothalamus fails to produce releasing hormones that stimulate the pituitary gland. What broad impact would this have on the entire endocrine system?
→ 2A person has difficulty understanding spoken language despite hearing it clearly, and also struggles with producing coherent speech. Which lobe of the cerebrum is likely affected?
→ 3Mimosa pudica (Touch-me-not plant) folds its leaves rapidly upon touch. Is this an example of tropism or nastism, and why?
→ 4Tabulate two key differences between the nervous system and the hormonal system in terms of their speed and duration of action.
→ 5Explain why a person with hyperthyroidism (overactive thyroid gland) might experience weight loss despite an increased appetite.
→ 6Farmers prune the shoot tips of plants to make them bushy. Which plant hormone's action is being counteracted by this practice?
→ 7Why is it important for the brain to be protected by the skull and cerebrospinal fluid?
→ 8Which hormone is responsible for regulating the basal metabolic rate of the body?
→ 9If a plant is grown in a completely dark environment, but rotated regularly on a clinostat, how would its growth be affected, particularly concerning geotropism?
→ 10How does the central nervous system distinguish between different types of sensory stimuli (e.g., light vs. sound vs. touch) despite all signals being electrical impulses?
→ 11What could be the long-term health consequences of an untreated deficiency of growth hormone in a child?
→ 12Why do complex organisms have specialized organs like the brain for coordination, whereas simpler organisms might not?
→ 13A scientist observes that the shoot of a plant grows straight upwards even when exposed to light from only one side, while another plant of the same species bends towards the light. What might explain this difference in the first plant?
→ 14If a person's blood calcium levels are consistently very low, which gland might be malfunctioning, and what hormone would be deficient?
→ 15Distinguish between voluntary and involuntary actions with respect to their control mechanisms in the nervous system.
→ 16Which plant hormone is known as a stress hormone and plays a role in closing stomata during water stress?
→ 17What would be the likely consequence of damage to the myelin sheath around axons in the central nervous system?
→ 18A teenager is undergoing significant physical changes, including the development of secondary sexual characteristics. Which pair of hormones is primarily responsible for these changes in males and females, respectively?
→ 19Why do plants respond differently to gravity depending on whether it's a shoot or a root?
→ 20A doctor taps the knee of a patient, causing an involuntary kick. What does this test assess, and what components of the nervous system are involved?
→ 21How do insulin and glucagon work antagonistically to maintain blood glucose homeostasis?
→ 22Which plant hormone is commonly sprayed on grapes to increase the size of the fruit and to make the stalks longer?
→ 23If the medulla oblongata is severely damaged, what immediate and critical effects would be observed in a person?
→ 24A deficiency of iodine in the diet can lead to a condition called goitre. Explain the underlying hormonal mechanism for this condition.
→ 25Why are reflex actions crucial for the survival of an organism? Give two reasons.
→ 26A plant growing in a dark room bends towards a window through which light enters. Which phytohormone is primarily responsible for this bending, and how does it cause this effect?
→ 27Why is the pituitary gland often referred to as the "master gland," despite being controlled by the hypothalamus?
→ 28If a person loses the ability to feel pain or temperature changes on their skin, which part of the cerebrum is likely affected?
→ 29Compare the roles of auxins and gibberellins in plant growth and development.
→ 30A person consumes a meal rich in carbohydrates. Describe the hormonal response and its effect on blood glucose levels.
→ 31In a reflex arc, if the sensory neuron is damaged, how would this affect the reflex action?
→ 32Plants do not have a nervous system like animals. How do they achieve coordination and respond to environmental stimuli effectively?
→ 33During a sudden emergency, a person experiences a rapid increase in heart rate, dilated pupils, and increased sweating. Which endocrine gland is primarily responsible for these physiological changes?
→ 34Why is a synapse considered a critical point for the integration and modulation of nerve signals?
→ 35What is the primary difference in function between the cerebrum and the medulla oblongata?
→ 36Farmers often spray ripening fruit with a gaseous hormone to accelerate the process. Identify this hormone and explain its role.
→ 37Describe the negative feedback mechanism involved in the regulation of blood glucose levels.
→ 38How does the structure of a neuron facilitate the rapid transmission of nerve impulses over long distances?
→ 39A child is observed to have stunted growth and mental retardation. A deficiency of which hormone during early development could be responsible for these symptoms?
→ 40Why is it essential for seeds to have a period of dormancy before germination, and which plant hormone plays a crucial role in maintaining this dormancy?
→ 41A person suffers a stroke that causes paralysis on the right side of their body. Which hemisphere of the brain was most likely affected?
→ 42Differentiate between tropic and nastic movements in plants, providing an example for each.
→ 43Assertion (A): Adrenaline is known as the "fight or flight" hormone. Reason (R): It prepares the body for extreme physical exertion in situations of stress or danger by increasing heart rate, blood pressure, and diverting blood to skeletal muscles.
→ 44Damage to which part of the human brain would most directly impair a person's ability to maintain balance and coordinate precise muscle movements, such as walking a straight line or catching a ball?
→ 45If a potted plant is placed horizontally for several days, the shoot grows upwards and the roots grow downwards. What type of tropism is primarily responsible for this observation?
→ 46A patient exhibits symptoms like increased blood glucose levels, frequent urination, and excessive thirst. Which hormone is likely deficient or ineffective in this patient?
→ 47A gardener wants to promote root formation in plant cuttings. Which plant hormone would be most suitable to apply?
→ 48Explain why the response of an endocrine system is generally slower but more widespread and prolonged compared to the nervous system.
→ 49A person accidentally touches a hot plate and immediately withdraws their hand. What is the correct sequence of components involved in this reflex action?
→ 50Which of the following is an example of an involuntary action controlled by the medulla?
→ 51A nerve impulse is essentially a flow of:
→ 52The control and coordination in plants is mainly achieved by:
→ 53Which of the following is not a plant hormone?
→ 54What is the role of an olfactoreceptor?
→ 55The part of the human brain that deals with emotions, learning, and memory is primarily the:
→ 56The hormone responsible for the development of secondary sexual characteristics in females is:
→ 57What is the function of cerebrospinal fluid?
→ 58Which of the following is a non-directional movement?
→ 59The endocrine gland located near the stomach that produces digestive enzymes and hormones is the:
→ 60What is the primary role of the motor neurons?
→ 61The response of a plant to gravity is called:
→ 62Which of the following is not a part of the human brain?
→ 63The feedback mechanism that regulates the secretion of hormones like thyroxine is typically:
→ 64Which of these is a plant hormone that promotes stem elongation and cell division?
→ 65What is the role of interneurons (relay neurons) in the reflex arc?
→ 66The specialized tip of a neuron that transmits signals to another neuron or an effector cell is the:
→ 67The thyroid gland secretes a hormone called:
→ 68Which plant hormone helps in the closing of stomata under water stress?
→ 69The growth of a root towards water is an example of:
→ 70Which part of the brain is the main control center for vision?
→ 71A sudden, involuntary response to a stimulus is called a:
→ 72The function of the gustatory receptors is to detect:
→ 73Which of the following statements describes the main difference between plant and animal hormones?
→ 74The condition characterized by abnormally high growth due to excess growth hormone is called:
→ 75Myelin sheath in neurons helps to:
→ 76What is the general direction of nerve impulse transmission within a neuron?
→ 77The ability of living organisms to respond to stimuli is called:
→ 78Which hormone is secreted by the adrenal medulla?
→ 79The part of the human brain that is responsible for our sense of hearing and smell is located in the:
→ 80The immediate cause of the leaves of the 'touch-me-not' plant drooping upon touching is:
→ 81The nervous system primarily uses ______________ signals, while the endocrine system primarily uses ______________ signals.
→ 82Which gland is responsible for secreting sex hormones in females?
→ 83The role of the Pons in the brain is to:
→ 84A plant stem growing towards light shows:
→ 85The main function of taste buds is to:
→ 86The outer protective layer of the brain is called the:
→ 87Which of the following statements about tropic movements is correct?
→ 88A person suffering from diabetes may be advised to take injections of:
→ 89The structure of the brain that connects the two cerebral hemispheres is the:
→ 90The cells that provide support and nutrition to neurons are called:
→ 91Which of these is a response to light in a plant, but is a non-directional movement?
→ 92What happens at the synapse?
→ 93The growth of tendrils around a support is an example of:
→ 94The dropping of leaves in plants in response to cold weather or drought is promoted by:
→ 95Which system prepares the body for action in stressful situations?
→ 96The 'fight or flight' hormone is:
→ 97Which of the following is a feature of hormones?
→ 98What is the main function of the hypothalamus?
→ 99The part of the forebrain specialized for hearing, smell, memory, and emotions is the:
→ 100Diabetes is caused by the inability of the body to produce sufficient:
→ 101Which plant hormone is involved in breaking seed dormancy?
→ 102The role of the 'effector' in a reflex arc is to:
→ 103Which of the following is responsible for converting electrical signals into chemical signals at the synapse?
→ 104What is the role of receptors in the nervous system?
→ 105The peripheral nervous system (PNS) consists of:
→ 106The central nervous system (CNS) includes:
→ 107The junction where an impulse is transmitted from one neuron to another is called a:
→ 108The neuron consists of:
→ 109Which hormone is responsible for the development of secondary sexual characteristics in males?
→ 110Nastic movements in plants are:
→ 111Which part of the brain controls involuntary actions like breathing, heartbeat, and blood pressure?
→ 112The movement of water-sensitive roots towards water is an example of:
→ 113Lack of growth hormone during childhood leads to:
→ 114A plant hormone that promotes cell division is:
→ 115The main function of the spinal cord is to:
→ 116Which of the following hormones is secreted in response to stress or emergency situations?
→ 117The phenomenon of plants bending towards a source of light is called:
→ 118What protects the brain from physical shocks?
→ 119The part of the neuron that receives information from other neurons is the:
→ 120Sensory receptors in the skin that detect touch are called:
→ 121The chemical messengers secreted by endocrine glands are called:
→ 122The main coordinating center of the body is the:
→ 123Which plant hormone inhibits growth and promotes dormancy?
→ 124The hormone that regulates the basal metabolism rate in the body is:
→ 125Root growing downwards into the soil is an example of:
→ 126The cerebrum is the part of the brain responsible for:
→ 127Which of the following is a tropic movement?
→ 128The hormone insulin is secreted by the:
→ 129Touching a hot object and immediately withdrawing the hand is an example of:
→ 130The functional unit of the nervous system is the:
→ 131Which plant hormone promotes fruit ripening?
→ 132Deficiency of iodine in the diet can lead to:
→ 133Which of the following is an involuntary action?
→ 134Which gland is known as the master gland?
→ 135The growth of pollen tubes towards ovules is an example of:
→ 136The gap between two neurons is called a:
→ 137The plant hormone responsible for cell elongation in shoots and phototropism is:
→ 138Which of the following is a component of the reflex arc?
→ 139The main function of the human brain is to:
→ 140The two main systems of control and coordination in higher animals are:
→ 141The regulation of blood pressure and heart rate during an emergency is mainly controlled by:
→ 142Which of the following is an example of a tropic movement in plants?
→ 143Plants use hormones for:
→ 144Which hormone is secreted by the pituitary gland to control the growth of bones and muscles?
→ 145When you touch a hot object, your hand immediately pulls away. This action is coordinated by the:
→ 146The ability to write, speak, and solve problems is controlled by the:
→ 147Which plant hormone delays the aging of leaves?
→ 148The growth of a tendril around a support is due to a differential growth rate between the side in contact with the support and the side away from the support. This is:
→ 149If the optic nerve is damaged, which sensation will be affected?
→ 150The primary difference between a reflex action and walking is that reflex action is:
→ 151A condition characterized by protruding eyes, weight loss, and increased metabolism is due to the overactivity of which gland?
→ 152Which plant hormone is responsible for breaking seed dormancy?
→ 153The relay neurons are found in the:
→ 154Which of the following protects the spinal cord?
→ 155The brain and spinal cord together constitute the:
→ 156Which of the following ensures that a plant grows in the correct direction relative to its environment?
→ 157A patient reports excessive thirst and frequent urination. These symptoms could indicate a problem with the regulation of:
→ 158Which gland produces both hormones and digestive enzymes?
→ 159The role of effectors in the nervous system is to:
→ 160The role of receptors in the nervous system is to:
→ 161Increased secretion of growth hormone in adulthood can lead to:
→ 162If a person has low levels of growth hormone in childhood, they may suffer from:
→ 163The main function of the thyroid gland is to:
→ 164Which part of the brain coordinates the function of various organs in the body?
→ 165The space between the axon terminal of one neuron and the dendrite of another neuron is called the:
→ 166Which of the following is a specialized end of a neuron that releases chemical substances at the synapse?
→ 167The receptors for smell are located in the:
→ 168Which system provides slower responses in animals, but its effects are generally long-lasting?
→ 169Which system provides faster responses in animals, but its effects are generally short-lived?
→ 170The hormone responsible for the 'apical dominance' phenomenon in plants is:
→ 171Which of the following hormones is associated with seed dormancy?
→ 172When a seed germinates, the shoot grows upwards. This is:
→ 173The opening and closing of stomata is regulated by:
→ 174Which movement in plants is non-directional and independent of the direction of stimulus?
→ 175The response of plant roots to move towards water is called:
→ 176Which hormone prepares the uterus for pregnancy?
→ 177The pancreas secretes:
→ 178Which hormone is secreted by the adrenal glands?
→ 179The main function of the hypothalamus is to:
→ 180Which type of neuron carries impulses from the central nervous system to the muscles or glands?
→ 181The insulating sheath around the axon of a neuron is called:
→ 182The longest part of a neuron is typically the:
→ 183Which part of the brain is responsible for interpreting sensations like touch, pain, and temperature?
→ 184Damage to the medulla oblongata would most likely affect:
→ 185The main function of the cerebellum is to:
→ 186Which of the following is a growth-inhibiting hormone in plants?
→ 187The increase in growth of a plant stem due to light is mediated by:
→ 188A plant's root generally shows:
→ 189A plant's shoot generally shows:
→ 190The leaves of the Mimosa pudica plant (touch-me-not) fold up when touched. This is an example of:
→ 191Which of the following is NOT a type of tropism?
→ 192Tendrils coiling around a support is an example of:
→ 193The growth of pollen tubes towards the ovules is an example of:
→ 194The movement of a plant part in response to gravity is called:
→ 195Which gaseous plant hormone is responsible for fruit ripening?
→ 196The plant hormone that inhibits growth and causes wilting of leaves is:
→ 197Which plant hormone promotes cell division?
→ 198Which plant hormone is primarily responsible for stem elongation and seed germination?
→ 199Roots growing downwards into the soil is an example of:
→ 200The bending of a plant shoot towards light is an example of:
→ 201Which plant hormone promotes cell elongation and is responsible for phototropism?
→ 202Which of the following represents a negative feedback mechanism?
→ 203The timing and amount of hormone release are regulated by:
→ 204The female sex hormones are:
→ 205Which of the following is a male sex hormone?
→ 206A person suffering from diabetes has a deficiency of which hormone?
→ 207The hormone that regulates blood sugar levels is:
→ 208Which hormone is released in response to stress or danger, preparing the body for "fight or flight"?
→ 209Deficiency of iodine in the diet can lead to a condition called:
→ 210The hormone responsible for regulating the basal metabolic rate in the body is:
→ 211Which gland is known as the "master gland" because it controls the activity of other endocrine glands?
→ 212Sensory information from the body reaches the brain through the:
→ 213The spinal cord originates from the:
→ 214Which of these is NOT a part of the hindbrain?
→ 215The fluid that protects the brain from mechanical shocks is:
→ 216The brain is protected by a bony box called the:
→ 217The hunger and thirst centers in the brain are located in the:
→ 218Which part of the brain controls voluntary movements?
→ 219Involuntary actions like salivation, vomiting, and blood pressure are controlled by the:
→ 220Which part of the brain is responsible for maintaining posture and balance of the body?
→ 221The main thinking part of the human brain is the:
→ 222Which of the following is an example of a reflex action?
→ 223The quick, spontaneous, and involuntary response to a stimulus is called a:
→ 224Which part of the central nervous system controls reflex actions?
→ 225The components of a reflex arc include all of the following EXCEPT:
→ 226A reflex action is an example of:
→ 227Chemicals that transmit nerve impulses across a synapse are called:
→ 228The pathway of a nerve impulse in a neuron is generally:
→ 229Which part of the neuron receives information?
→ 230The junction between two neurons is called a:
→ 231Which of the following is the structural and functional unit of the nervous system?
→ 232What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
→ 233Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
→ 234How are involuntary actions and reflex actions different from each other?
→ 235What is the need for a system of control and coordination in an organism?
→ 236How does chemical coordination occur in plants?
→ 237Which signals will get disrupted in case of a spinal cord injury?
→ 238How does phototropism occur in plants?
→ 239What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
→ 240The brain is responsible for (a) thinking. (b) regulating the heart beat. (c) balancing the body. (d) all of the above.
→ 241The gap between two neurons is called a (a) dendrite. (b) synapse. (c) axon. (d) impulse
→ 242Which of the following is a plant hormone? (a) Insulin (b) Thyroxin (c) Oestrogen (d) Cytokinin.
→ 243Why are some patients of diabetes treated by giving injections of insulin?
→ 244How does our body respond when adrenaline is secreted into the blood?
→ 245Why is the use of iodised salt advisable?
→ 246How does chemical coordination take place in animals?
→ 247How do auxins promote the growth of a tendril around a support?
→ 248Give an example of a plant hormone that promotes growth.
→ 249How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?
→ 250What are plant hormones?
→ 251What is the role of the brain in reflex action?
→ 252How do we detect the smell of an agarbatti (incense stick)?
→ 253Which part of the brain maintains posture and equilibrium of the body?
→ 254What happens at the synapse between two neurons?
→ 255What is the difference between a reflex action and walking?
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