Control and Coordination: Class 10 Science Practice Questions

Rahul is a 16-year-old student preparing for his board exams. One evening, while walking home, he suddenly notices a stray dog rushing towards him. His heart starts beating very fast, his breathing rate increases, and his palms begin to sweat. He manages to run away safely. Later that night, while studying, Rahul accidentally touches a hot test tube during a practical revision. He immediately withdraws his hand before he even realises the pain. His biology teacher explains the next day that two entirely different control and coordination systems were responsible for these two events.

Read the following passage and answer the questions that follow:

Rahul is a 16-year-old student preparing for his board exams. One evening, while walking home, he suddenly notices a stray dog rushing towards him. His heart starts beating very fast, his breathing rate increases, and his palms begin to sweat. He manages to run away safely. Later that night, while studying, Rahul accidentally touches a hot test tube during a practical revision. He immediately withdraws his hand before he even realises the pain. His biology teacher explains the next day that two entirely different control and coordination systems were responsible for these two events.

(a) Name the hormone responsible for the changes Rahul experienced when he saw the dog rushing towards him. Which endocrine gland secretes this hormone?

(b) Name the type of nervous response that caused Rahul to withdraw his hand from the hot test tube. State the part of the nervous system that controls this response.

(c) The teacher says that the response to the dog involved a 'slower but longer-lasting' system, while the response to the hot test tube involved a 'faster but short-lived' system. Justify this statement by explaining how each system achieves its effect in the body.

Priya is a 16-year-old student who fractured her right arm in a sports accident. After the fracture healed, her doctor noticed that the muscles of her right arm had become noticeably weaker and thinner compared to her left arm — even though the bones had healed completely. The doctor explained that during the weeks her arm was in a cast, the nerves supplying those muscles were partially compressed and not functioning normally.

Priya is a 16-year-old student who fractured her right arm in a sports accident. After the fracture healed, her doctor noticed that the muscles of her right arm had become noticeably weaker and thinner compared to her left arm — even though the bones had healed completely. The doctor explained that during the weeks her arm was in a cast, the nerves supplying those muscles were partially compressed and not functioning normally.

Based on the above information, answer the following questions:

(a) Name the type of neurons that carry signals FROM the brain/spinal cord TO the muscles of Priya's arm. What would happen to the muscle if these neurons stopped functioning completely?

(b) When Priya accidentally touches a hot utensil with her LEFT hand (her unaffected hand), she withdraws it instantly before feeling the pain. Name the type of nervous response involved. Where exactly is the nerve centre (controlling centre) for this response located?

(c) The doctor advises Priya to do specific exercises to help her weakened arm recover. Explain how TWO different chemical coordination mechanisms in her body — one that acts quickly to increase blood flow and energy supply to the muscles during exercise, and one that acts slowly over weeks to help rebuild the weakened muscle tissue — contribute to her recovery. Name the specific hormone involved in each case.

Rahul, a class 10 student, was performing a science experiment in the school garden. He noticed that a potted bean plant near the window had its stem curving towards the sunlight, while its roots were growing downward into the soil. His teacher explained that these movements are controlled by a plant hormone that is unevenly distributed in response to environmental stimuli. Later in the laboratory, Rahul accidentally touched a hot beaker. He instantly withdrew his hand even before he felt the pain. His teacher told him that this withdrawal was not controlled by the brain but by a different part of the nervous system, and the pain was felt only a moment later when the brain processed the signal.

Read the following case and answer the questions that follow:

Rahul, a class 10 student, was performing a science experiment in the school garden. He noticed that a potted bean plant near the window had its stem curving towards the sunlight, while its roots were growing downward into the soil. His teacher explained that these movements are controlled by a plant hormone that is unevenly distributed in response to environmental stimuli. Later in the laboratory, Rahul accidentally touched a hot beaker. He instantly withdrew his hand even before he felt the pain. His teacher told him that this withdrawal was not controlled by the brain but by a different part of the nervous system, and the pain was felt only a moment later when the brain processed the signal.

(a) Name the plant hormone responsible for the bending of the bean stem towards light. Which type of tropism is this, and in which direction does this hormone accumulate to cause bending? [1 mark]

(b) The roots of the same plant grow downward into the soil. Identify the type of tropism shown by the roots. How does the same hormone that causes the stem to bend towards light have the OPPOSITE effect on the root? [1 mark]

(c) Name the specific part of the nervous system that controlled Rahul's hand withdrawal BEFORE his brain registered pain. Draw a labelled diagram of the pathway that caused this response, naming at least four components involved. [2 marks]

During a marathon training camp organised at the Sardar Patel Stadium in Ahmedabad, Gujarat, sports physiologist Dr. Meena explained to the athletes how their nervous system coordinates body movements. She described that when a runner's foot strikes a sharp pebble on the track, a nerve impulse travels from the foot's receptor at a speed of approximately 120 metres per second along sensory neurons to the spinal cord, which is located about 1.0 metre away from the foot. The spinal cord acts as the reflex centre and sends a motor impulse back to the leg muscles, also covering a distance of 1.0 metre, so the total distance travelled by impulses in this spinal reflex arc is 2.0 metres. Dr. Meena further explained that the human brain, which forms the central processing unit of the nervous system, weighs about 1.4 kg and contains approximately 100 billion neurons, each connected to thousands of others through junctions called synapses.

During a marathon training camp organised at the Sardar Patel Stadium in Ahmedabad, Gujarat, sports physiologist Dr. Meena explained to the athletes how their nervous system coordinates body movements. She described that when a runner's foot strikes a sharp pebble on the track, a nerve impulse travels from the foot's receptor at a speed of approximately 120 metres per second along sensory neurons to the spinal cord, which is located about 1.0 metre away from the foot. The spinal cord acts as the reflex centre and sends a motor impulse back to the leg muscles, also covering a distance of 1.0 metre, so the total distance travelled by impulses in this spinal reflex arc is 2.0 metres. Dr. Meena further explained that the human brain, which forms the central processing unit of the nervous system, weighs about 1.4 kg and contains approximately 100 billion neurons, each connected to thousands of others through junctions called synapses.

During a first-aid training camp organised at a Government Medical College in Shimla, Himachal Pradesh, Dr. Kavita, a neurologist, explained the working of the human nervous system to a group of nursing students. She described how a nerve cell (neuron) consists of a cell body, dendrites, and an axon. She mentioned that the axon of a motor neuron in the human body can be up to 1 metre long, while a typical dendrite is only about 1 mm in length. She further explained that a nerve impulse travels along the neuron and crosses the gap between two neurons called a synapse, and that the human brain weighs approximately 1.4 kg and contains nearly 100 billion neurons. She divided the entire nervous system into the Central Nervous System (CNS), comprising the brain and spinal cord, and the Peripheral Nervous System (PNS), comprising cranial and spinal nerves.

During a first-aid training camp organised at a Government Medical College in Shimla, Himachal Pradesh, Dr. Kavita, a neurologist, explained the working of the human nervous system to a group of nursing students. She described how a nerve cell (neuron) consists of a cell body, dendrites, and an axon. She mentioned that the axon of a motor neuron in the human body can be up to 1 metre long, while a typical dendrite is only about 1 mm in length. She further explained that a nerve impulse travels along the neuron and crosses the gap between two neurons called a synapse, and that the human brain weighs approximately 1.4 kg and contains nearly 100 billion neurons. She divided the entire nervous system into the Central Nervous System (CNS), comprising the brain and spinal cord, and the Peripheral Nervous System (PNS), comprising cranial and spinal nerves.

During a rehabilitation workshop organised at a neuroscience awareness camp in Mysuru, Karnataka, Dr. Meena, a neurologist, explained the structure and functions of the human brain to a group of Class 10 students. She used a labelled model showing that the brain is divided into three main regions: the forebrain (cerebrum), midbrain, and hindbrain (cerebellum and medulla oblongata). She highlighted that the cerebrum accounts for about 85% of the total brain weight of 1,400 grams, while the cerebellum accounts for 10% and the medulla oblongata accounts for the remaining 5%. Dr. Meena described how each part performs distinct and vital functions that keep the human body working in a coordinated manner.

During a rehabilitation workshop organised at a neuroscience awareness camp in Mysuru, Karnataka, Dr. Meena, a neurologist, explained the structure and functions of the human brain to a group of Class 10 students. She used a labelled model showing that the brain is divided into three main regions: the forebrain (cerebrum), midbrain, and hindbrain (cerebellum and medulla oblongata). She highlighted that the cerebrum accounts for about 85% of the total brain weight of 1,400 grams, while the cerebellum accounts for 10% and the medulla oblongata accounts for the remaining 5%. Dr. Meena described how each part performs distinct and vital functions that keep the human body working in a coordinated manner.

Rahul, a 16-year-old student, was studying late at night. While reaching for his water bottle in the dark, he accidentally touched a hot lamp. His hand jerked back almost instantly — long before he felt any pain. His teacher later explained that this rapid withdrawal was not controlled by his brain, but by a nerve pathway involving his spinal cord. The teacher also told him that the sensation of pain was felt a fraction of a second later, when a signal finally reached his brain.

The next day in the biology lab, Rahul observed a potted plant kept near a window. He noticed that its stem was bending towards the light. His teacher explained that unlike Rahul's reflex, this movement in plants involved no nervous system — instead, it was controlled by a chemical that causes unequal growth on the two sides of the stem.

Read the following case study and answer the questions that follow:

Rahul, a 16-year-old student, was studying late at night. While reaching for his water bottle in the dark, he accidentally touched a hot lamp. His hand jerked back almost instantly — long before he felt any pain. His teacher later explained that this rapid withdrawal was not controlled by his brain, but by a nerve pathway involving his spinal cord. The teacher also told him that the sensation of pain was felt a fraction of a second later, when a signal finally reached his brain.

The next day in the biology lab, Rahul observed a potted plant kept near a window. He noticed that its stem was bending towards the light. His teacher explained that unlike Rahul's reflex, this movement in plants involved no nervous system — instead, it was controlled by a chemical that causes unequal growth on the two sides of the stem.

(a) Name the type of response Rahul showed when his hand jerked back from the hot lamp. Name the coordination centre involved in this response.

(b) The pain sensation was felt by Rahul slightly after the withdrawal of his hand. What does this tell us about the role of the brain in a reflex action?

(c) (i) Name the phenomenon shown by the plant stem bending towards light. Name the chemical responsible for this response.
(ii) Explain why the stem bends towards the source of light and not away from it. How is this response different from Rahul's reflex in terms of the type of control involved?

During a neuroscience awareness programme organised at a government school in Ranchi, Jharkhand, Class 10 students participated in a workshop conducted by Dr. Suresh, a neurologist from RIMS Hospital. He demonstrated how the human nervous system works using a model showing a typical neuron with its dendrites, cell body, and axon. He explained that a nerve impulse travels along a neuron at an average speed of 120 metres per second in myelinated nerve fibres, and that the axon in the model represented was 0.6 metres long. He further explained that the brain and spinal cord together form the central nervous system (CNS), while the nerves arising from them form the peripheral nervous system (PNS). The students were shown that information passes from one neuron to the next through a junction called a synapse.

During a neuroscience awareness programme organised at a government school in Ranchi, Jharkhand, Class 10 students participated in a workshop conducted by Dr. Suresh, a neurologist from RIMS Hospital. He demonstrated how the human nervous system works using a model showing a typical neuron with its dendrites, cell body, and axon. He explained that a nerve impulse travels along a neuron at an average speed of 120 metres per second in myelinated nerve fibres, and that the axon in the model represented was 0.6 metres long. He further explained that the brain and spinal cord together form the central nervous system (CNS), while the nerves arising from them form the peripheral nervous system (PNS). The students were shown that information passes from one neuron to the next through a junction called a synapse.

During an examination, a student feels extremely nervous and her heart begins to beat faster than normal. Which of the following correctly identifies the hormone responsible for this response AND the gland that secretes it?

Name the gland that secretes insulin and state its function in the human body.

Which of the following correctly pairs two animal hormones with the glands that secrete them?

A child shows stunted growth and abnormally short stature despite having a balanced diet. This condition is most likely caused by inadequate secretion of which hormone?

Which of the following plant hormones is primarily responsible for promoting cell elongation in stems and is also involved in apical dominance?

A gardener observes that when water is available only on one side of the soil, the roots of a sunflower seedling curve and grow towards that moist region, even if it means growing sideways. This directional growth response of the root towards moisture is called:

A farmer notices that one side of his sunflower seedlings bends towards a light source placed on the left. Which plant hormone is responsible for this unequal growth, and on which side of the stem does it accumulate in higher concentration?

A student notices that when a potted plant is kept near a window, its stem bends and grows towards the light source over a period of days. This directional growth response of the shoot towards light is caused by unequal distribution of which hormone?

The plant hormones responsible for promoting fruit ripening and for stimulating seed germination and stem elongation respectively are:

Which of the following correctly pairs a plant hormone with its PRIMARY function?

A student places a potted plant horizontally on a table in a dark room for 48 hours. After observation, the student notices that the shoot has curved upward while the root has curved downward. Which of the following statements correctly explains this observation?

(1) Both shoot and root show positive geotropism
(2) Shoot shows negative geotropism; root shows positive geotropism
(3) Shoot shows positive phototropism; root shows negative phototropism
(4) Both shoot and root show negative geotropism

The plant hormones responsible for promoting cell elongation on the shaded side of a shoot and for inhibiting growth during unfavourable conditions respectively are:

Which of the following correctly identifies a pair of endocrine glands that are located in the abdomen of the human body?

Which of the following endocrine glands is present as a SINGLE (unpaired) structure in the human body?

A botanist observes that when an auxin-producing shoot tip is exposed to light from one side only, the auxin migrates to the shaded side of the shoot. Which of the following correctly describes what happens as a result of this unequal auxin distribution?

The plant hormones responsible for promoting apical dominance by suppressing lateral bud growth and for causing stomatal closure during water stress respectively are:

A climbing plant such as a pea plant wraps its tendrils around a support stick when it comes in contact with it. This movement of the tendril is an example of:

The plant hormones responsible for promoting cell elongation in roots towards gravity and for delaying leaf senescence (ageing) respectively are:

Name the hormone secreted by the thyroid gland and state one function of this hormone.

A cricket player suddenly blinks his eyes when a ball is bowled directly towards his face, even before he consciously decides to do so. (i) Name the type of nervous action involved and identify the part of the nervous system that coordinates it. (ii) State the role of the sensory neuron and the motor neuron in completing this response.

A child accidentally places his finger on a burning candle flame and immediately withdraws it even before consciously feeling the pain. Write the sequence of events, in correct order, that occur from the moment the flame contacts the finger to the withdrawal of the finger. Also, state why this response is faster than a voluntary action.

Study the table given below showing Growth Hormone (GH) levels in children at different stages of development.

Stage | Normal GH Level (ng/mL) | Deficient GH Level (ng/mL) | Excess GH Level (ng/mL)
Early Childhood (2–6 yrs) | 1–10 | < 1 | > 20
Pre-adolescence (7–12 yrs) | 1–14 | < 1 | > 25

(i) Name the endocrine gland that secretes Growth Hormone and state where it is located in the human body.
(ii) Based on the table, predict ONE disorder that would develop in a child of age 9 years whose GH level is consistently recorded at 0.4 ng/mL, and give a reason for your answer.