7. Control and Coordination

SEBA Class 10 Science Chapter 7 Control and Coordination

Chapter 7. Control and Coordination

Class 10 Chapter 7 Control and Coordination Multiple Choice Questions and Answers :

Question : Which of the following is a plant hormone?

(a) Insulin

(b) Thyroxin

(d) Cytokinin.

Answer : (d) Cytokinin.

Question : The gap between two neurons is called a

(a) dendrite.

(b) synapse.

(d) impulse.

Answer : (b) synapse.

Question : The brain is responsible for

(a) thinking.

(b) regulating the heart beat.

(d) all of the above.

Answer : (d) all of the above.

Question : The plant hormone which stimulates cell division is : [SEBA 2015]

(a) Auxin

(b) Cytokinin

(d) Gibberelin

Answer : (b) Cytokinin .

[Cytokinins promote cell division, and it is natural then that they are present in greater concentration in areas of rapid cell division, such as in fruits and seeds.]

Question : The part of the brain which is responsible for maintaining equilibrium and posture of the body is : [SEBA2016]

(a) Cerebellum

(b) Medulla

(d) Cerebrum

Answer : (a) Cerebellum .

[The part of the brain that is responsible for maintaining equilibrium and posture of the body is Cerebellum. The cerebellum is involved in coordinating voluntary muscle movements, maintaining balance, and regulating muscle tone .]

Question : The hormone which causes wilting of leaves is :[SEBA 2017]

(a) Auxin

(b) Gibberellin

(d) Cytokinin

Answer : (c) Abscisic acid .

[The hormone which causes wilting of leaves is abscisic acid. ]

Question : The hormone produced by the pancreas that helps in regulating the blood sugar level is :[SEBA 2018]

(a) adrenalin

(b) thyroxin

(d) testosterone

Answer : (c) insulin .

[The hormone produced by the pancreas that helps in regulating the blood sugar level is insulin. Insulin plays a crucial role in glucose metabolism by facilitating the uptake of glucose into cells, especially in the liver, muscle, and adipose tissue. ]

Question : The part of the brain responsible for the sensation of hunger and thirst is :[SEBA 2018]

(a) forebrain

(b) midbrain

(d) hypothalamus

Answer : (d) hypothalamus .

[The part of the brain responsible for the sensation of hunger and thirst is hypothalamus. The hypothalamus, which is located in the forebrain, plays a crucial role in regulating various physiological processes, including hunger, thirst, body temperature, and circadian rhythms .]

Question : The part of the brain that controls the posture and equilibrium of our body is [SEBA 2019]

(a) diencephalon

(b) cerebrum

(d) medulla oblongata

Answer : (c) cerebellum .

[The part of the brain that controls the posture and equilibrium of our body is cerebellum. The cerebellum is responsible for coordinating voluntary muscle movements, maintaining balance, and ensuring proper posture. It receives information from the sensory systems and helps in the smooth execution of movements.]

Question : Which of the following disease is caused due to the insufficient secretion of thyroxin hormone ?

(a) Beriberi

(b) Goiter

(d) Dwarfism

Answer : (b) Goiter .

[The disease caused due to the insufficient secretion of thyroxin hormone is goiter. Goiter is often associated with iodine deficiency, which is essential for the synthesis of thyroid hormones, including thyroxin. Insufficient thyroxin production can lead to the enlargement of the thyroid gland, resulting in the formation of a goiter. ]

Question : The growth inhibiting hormone found to be present in plants is : [SEBA 2021]

(a) Auxin

(b) gibberellin

(d) abscisic acid

Answer : (d) abscisic acid .

[The growth inhibiting hormone found to be present in plants is abscisic acid. Abscisic acid plays a role in various physiological processes, including the inhibition of growth, seed dormancy, and responses to environmental stress, particularly water stress.]

Question : The gap between the two neurons is called a [SEBA 2023 ]

(a) dendrite

(b) synapse

(d) nerve ending

Answer : (b) synapse .

[The gap between two neurons is called a synapse. Therefore, the correct answer is (b) synapse. The synapse is a specialized junction where the axon terminal of one neuron communicates with the dendrite or cell body of another neuron. ]

Question : Which of the following is a plant hormone ? [SEBA 2023]

(a) Insulin

(b) Thyroxin

(d) Cytokinin

Answer : (d) Cytokinin .

Question : A feedback mechanism regulates the action of the . [SEBA 2023]

Answer : Endocrine system .

[A feedback mechanism regulates the action of the endocrine system. The endocrine system is a complex network of glands that secrete hormones into the bloodstream to regulate various physiological processes in the body, such as metabolism, growth, and reproduction. Feedback mechanisms, both positive and negative, help maintain a balance in hormone levels and ensure proper functioning of the endocrine system.]

Question : Which of the following statements is correct about receptors?

(a) Gustatory receptors detect taste while olfactory receptors detect smell

(b) Both gustatory and olfactory receptors detect smell

(d) Olfactory receptors detect taste and gustatory receptors smell .

Answer : (a) Gustatory receptors detect taste while olfactory receptors detect smell.

[ Gustatory receptors are responsible for taste perception, while olfactory receptors detect odors in the sense of smell.]

Question : Electrical impulse travels in a neuron from

(a) Dendrite → axon → axonal end → cell body

(b) Cell body → dendrite → axon → axonal end

(d) Axonal end → axon → cell body → dendrite

Answer : (c) Dendrite → cell body → axon → axonal end.

[ The impulse typically starts at the dendrites, moves through the cell body, travels down the axon, and reaches the axonal end where it can transmit signals to other neurons or cells.]

Question : In a synapse, chemical signal is transmitted from

(a) dendritic end of one neuron to axonal end of another neuron

(b) axon to cell body of the same neuron

(d) axonal end of one neuron to dendritic end of another neuron .

Answer : (d) axonal end of one neuron to dendritic end of another neuron.

[ In a synapse, the chemical signal (neurotransmitters) is transmitted from the axonal end of one neuron to the dendritic end of another neuron.]

Question : In a neuron, conversion of electrical signal to a chemical signal occurs at/in

(a) cell body

(b) axonal end

(d) axon

Answer : (b) axonal end of a neuron.

[ At the axonal end, neurotransmitters are released into the synapse to transmit the signal to the next neuron or target cell. ]

Question : Which is the correct sequence of the components of a reflex arc?

(a) Receptors→ Muscles→ Sensory neuron→ Motor neuron→ Spinal cord

(b) Receptors→ Motor neuron → Spinal cord → Sensory neuron → Muscle

(d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle

Answer: (d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle.

[ The signal starts with the receptors detecting a stimulus, and the information is then transmitted through the sensory neuron to the spinal cord, where a quick response is generated through the motor neuron to the effector muscle.]

Question : Which of the following statements are true?

(i) Sudden action in response to something in the environment is called reflex action

(ii) Sensory neurons carry signals from spinal cord to muscles

(iii) Motor neurons carry signals from receptors to spinal cord

(iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc

(a) (i) and (ii) (b) (i) and (iii)

Answer : (c) (i) and (iv)

[ (i) Sudden action in response to something in the environment is called reflex action.

(iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called a reflex arc. ]

Question : Which of the following statements are true about the brain?

(i) The main thinking part of brain is hind brain

(ii) Centres of hearing, smell, memory, sight etc are located in fore brain.

(iii) Involuntary actions like salivation, vomiting, blood pressure are controlled by the medulla in the hind brain

(iv) Cerebellum does not control posture and balance of the body

(a) (i) and (ii) (b) (i), (ii) and (iii)

Answer : (c) (ii) and (iii)

[ (ii) Centers of hearing, smell, memory, sight, etc., are located in the forebrain. (iii) Involuntary actions like salivation, vomiting, blood pressure are controlled by the medulla in the hindbrain. ]

Question : Posture and balance of the body is controlled by

(a) cerebrum

(b) cerebellum

(d) pons

Answer : (b) cerebellum.

[ The cerebellum is responsible for coordinating voluntary movements and maintaining posture and balance in the body.]

Question : Spinal cord originates from

(a) cerebrum

(b) medulla

(d) cerebellum

Answer : (b) medulla

[ The spinal cord originates from the medulla, which is part of the brainstem.]

Question : The movement of shoot towards light is

(a) geotropism

(b) hydrotropism

(d) phototropism

Answer : (d) phototropism

[ The movement of a shoot towards light is phototropism. ]

Question : The main function of abscisic acid in plants is to

(a) increase the length of cells

(b) promote cell division

(d) promote growth of stem

Answer : (c) inhibit growth

[ The main function of abscisic acid in plants to inhibit growth. It plays a role in inducing dormancy and promoting abscission (shedding of leaves and fruits). ]

Question : Which of the following is not associated with growth of plant?

(a) Auxin

(b) Gibberellins

(d) Abscisic acid

Answer : (d) Abscisic acid .

[ Abscisic acid is not associated with the promotion of growth in plants. It is involved in inhibiting growth, inducing dormancy, and promoting abscission (shedding of leaves and fruits).]

Question : Iodine is necessary for the synthesis of which hormone?

(a) Adrenaline

(b) Thyroxin

(d) Insulin

Answer : (b) Thyroxin

[ Iodine is necessary for the synthesis of the thyroxin, which is a thyroid hormone.]

Question : Choose the incorrect statement about insulin

(a) It is produced from pancreas

(b) It regulates growth and development of the body

(d) Insufficient secretion of insulin will cause diabetes

Answer : (b) It regulates growth and development of the body.

[ Insulin primarily regulates blood sugar levels and does not directly control the growth and development of the body. ]

Question : Select the mis-matched pair

(a) Adrenaline : Pituitary gland

(b) Testosterone: Testes

(d) Thyroxin : Thyroid gland

Answer : (a) Adrenaline: Pituitary gland.

[ Adrenaline is produced by the adrenal glands, not the pituitary gland.]

Question : The shape of guard cells changes due to change in the

(a) protein composition of cells

(b) temperature of cells

(d) position of nucleus in the cells

Answer : (c) amount of water in cells.

[ The turgidity of guard cells, influenced by the water content, is crucial in controlling the opening and closing of stomata in plant leaves. ]

Question : The growth of tendril in pea plants is due to

(a) effect of light

(b) effect of gravity

(d) rapid cell divisions in tendrillar cells in contact with the support

Answer : (d) rapid cell divisions in tendrillar cells in contact with the support

[ The growth of tendril in pea plants is due to rapid cell divisions in tendrillar cells in contact with the support. Tendrils typically exhibit thigmotropism, a response to touch or contact with a support, which triggers the rapid cell division and coiling around the support.]

Question : The growth of pollen tubes towards ovules is due to

(a) hydrotropism

(b) chemotropism

(d) phototropism

Answer : (b) chemotropism.

[ Chemotropism is the growth or movement of an organism in response to a chemical stimulus, and in this case, it involves the attraction of pollen tubes toward chemicals released by ovules. ]

Question : The movement of sunflower in accordance with the path of sun is due to

(a) phototropism

(b) geotropism

(d) hydrotropism

Answer : (a) phototropism.

[ Phototropism is the growth or movement of an organism in response to light, and in the case of sunflowers, it causes them to follow the sun across the sky. ]

Question : The substance that triggers the fall of mature leaves and fruits from plants is due to

(a) auxin

(b) gibberellin

(d) cytokinin

Answer : (c) abscisic acid.

[ Abscisic acid is involved in promoting abscission, which is the shedding of leaves and fruits from a plant.]

Question : Which of the following statements about transmission of nerve impulse is incorrect?

(a) Nerve impulse travels from dendritic end towards axonal end

(b) At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron

(c) The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in a dendrite of another neuron

(d) A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells

Answer : (b) At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron.

[ This statement is inaccurate because, in a synapse, it is the release of chemicals (neurotransmitters) from the axonal end that influences the generation of an electrical impulse in the dendrite of another neuron.]

Question : Involuntary actions in the body are controlled by

(a) medulla in fore brain

(b) medulla in mid brain

(d) medulla in spinal cord

Answer : (c) medulla in hind brain .

[ Involuntary actions in the body are primarily controlled by medulla in the hindbrain.]

Question : Which of the following is not an involuntary action?

(a) Vomiting

(b) Salivation

(d) Chewing

Answer : (d) Chewing

[ Chewing is not an involuntary action. It is a voluntary action that can be consciously controlled by an individual. The other options—vomiting, salivation, and heart beat—are examples of involuntary actions that occur without conscious control.]

Question : When a person is suffering from severe cold, he or she cannot

(a) differentiate the taste of an apple from that of an ice cream

(b) differentiate the smell of a perfume from that of an agarbatti

(d) differentiate a hot object from a cold object

Answer : (b) differentiate the smell of a perfume from that of an agarbatti .

[ When a person is suffering from severe cold, he or she cannot differentiate the smell of a perfume from that of an agarbatti. This is because a blocked or congested nose can affect the sense of smell.]

Question : What is the correct direction of flow of electrical impulses?

Answer : (c)

Question : Which statement is not true about thyroxin?

(a) Iron is essential for the synthesis of thyroxin

(b) It regulates carbohydrates, protein and fat metabolism in the body

(d) Thyroxin is also called thyroid hormone

Answer : (a) Iron is essential for the synthesis of thyroxin.

[ Iodine is essential for the synthesis of thyroxin, not iron.]

Question : Dwarfism results due to

(a) Excess secretion of thyroxin

(b) Less secretion of growth hormone

(d) Excess secretion of growth hormone

Answer : (b) less secretion of growth hormone.

[ Insufficient production of growth hormone during childhood can lead to a slower rate of growth and result in dwarfism.]

Question : Dramatic changes of body features associated with puberty are mainly because of secretion of

(a) oestrogen from testes and testosterone from ovary

(b) estrogen from adrenal gland and testosterone from pituitary gland

(d) testosterone from thyroid gland and estrogen from pituitary gland

Answer : (c) testosterone from testes and estrogen from ovary.

[ Puberty-related changes in body features are primarily driven by the increased secretion of sex hormones, with testosterone being more prominent in males and estrogen in females.]

Question : A doctor advised a person to take an injection of insulin because

(a) his blood pressure was low

(b) his heart was beating slowly

(d) his sugar level in blood was high

Answer : (d) his sugar level in blood was high .

[ The doctor advised the person to take an injection of insulin because his sugar level in the blood was high. Insulin is a hormone that helps regulate blood sugar levels.]

Question : The hormone which increases the fertility in males is called

(a) oestrogen

(b) testosterone

(d) growth hormone

Answer : (b) testosterone

[ The hormone that increases fertility in males is testosterone.]

Question : Which of the following endocrine glands is unpaired?

(a) Adrenal

(b) Testes

(d) Ovary

Answer : (c) Pituitary.

[ The pituitary gland is a single, pea-sized gland located at the base of the brain.]

Question : Junction between two neurons is called

(a) cell junction

(b) neuro muscular junction

(d) synapse

Answer : (d) synapse

[ The junction between two neurons is called synapse. ]

Question : In humans, the life processes are controlled and regulated by

(a) reproductive and endocrine systems

(b) respiratory and nervous systems

(d) nervous and endocrine systems

Answer : (d) nervous and endocrine systems .

[ Nervous and endocrine systems are primarily responsible for controlling and regulating life processes in humans.]

Question : What is synapse ? How nerve impulse passes across synapse ? [SEBA 2015]

Answer : A synapse is a junction between two nerve cells, where electrical or chemical signals are transmitted. When an electrical impulse reaches the presynaptic neuron, it triggers the release of neurotransmitters, which diffuse across the synaptic gap and bind to receptors on the postsynaptic neuron, generating a new electrical signal.

Question : How Mimosa plant responses to stimulus ? [SEBA 2015]

Answer : The Mimosa plant responds to stimuli by rapidly closing its leaves when touched or disturbed. Movement occurs at a point different from the touch due to electrical-chemical communication between cells. Cells change shape by altering water content, causing swelling or shrinking, resulting in consequent movement.

Question : How nervous tissue maintains muscular movement ? [SEBA 2016]

Answer : Nervous tissue maintains muscular movement by transmitting electrical signals called action potentials along neurons. These signals travel from the central nervous system to motor neurons, which then stimulate muscle fibers to contract, allowing for coordinated movement.

Question : What is auxin ? How does it aid in the growth of a plant ? [SEBA 2020]

Answer : Auxin is a plant hormone synthesized at the shoot tip.

In response to light, auxin diffuses to the shady side of the shoot. Its concentration there stimulates cell elongation, causing the cells on the shaded side to grow longer. This directional growth allows the plant to bend towards the light source, facilitating phototropism.

Question : How muscle cells change their shape ? [SEBA 2020]

Answer : Muscle cells change shape in response to nervous electrical impulses. Special proteins within the cells alter both their shape and arrangement, leading to a shorter form when stimulated by these impulses.

Question : Write two difference between axon and dendrite . [SEBA 2019]

Answer : The difference between axon and dendrite are :

Characteristic	Axon	Dendrite
Structure	Long, single extension	Short, branched extensions
Function	Transmits signals away from cell	Receives signals and transmits them towards the cell body

Question : How does nerve impulse travel in our body ? [SEBA 2018]

Answer : Nerve impulses travel in our body by transmitting electrical signals along nerve cells. When a nerve impulse reaches a muscle, special proteins in muscle cells respond to the electrical signals, changing shape and arrangement, ultimately causing the muscle cells to shorten and produce movement.

Question : Write the function of Adrenaline hormone . [SEBA 2017]

Answer : Adrenaline, secreted from the adrenal glands, regulates various physiological responses in the body. It targets organs like the heart, increasing heart rate for enhanced oxygen supply to muscles, while constricting blood vessels in the digestive system and skin to redirect blood flow to skeletal muscles. Adrenaline also stimulates increased breathing rates.

Question : How does leaf movement of the sensitive plants differ from the shoot movement towards light ?

Answer : The leaf movement of sensitive plants is a thigmotropic response, folding upon touch or disturbance. In contrast, shoot movement towards light is a phototropic response, where shoots bend towards the light source. The mechanisms behind these movements highlight distinct tropic responses to environmental stimuli in plant parts.

Question : What is neuromuscular junction ? how does a nerves impulse travels from one part to the other part of the body ?

Answer : A neuromuscular junction is a connection between a motor neuron and a muscle fiber, where nerve impulses trigger muscle contraction. Nerve impulses travel through neurons as electrical signals. When an impulse reaches the neuromuscular junction, it prompts the release of neurotransmitters, transmitting the signal to the muscle fiber, leading to muscle contraction and movement.

Question : What is the importance of iodine in out body ?

Solution : Iodine is crucial for the synthesis of thyroxin hormone by the thyroid gland. Thyroxin regulates metabolism of carbohydrates, proteins, and fats, promoting balanced growth. Iodine deficiency may lead to conditions like goitre, characterized by a swollen neck.

Question : What is reflex ? Why reflex are developed in animals ? Write the components of reflex arc .

Answer : A reflex is a rapid, involuntary response to a stimulus that occurs without conscious thought.

Reflexes are developed in animals to enable swift reactions to potentially harmful or beneficial stimuli, aiding in survival and adaptation to the environment.

The components of a reflex arc : a sensory receptor, sensory neuron, interneuron (sometimes), motor neuron, and effector organ or muscle.

Question : What are the endocrine glands ? What is the difference an endocrine and exocrine gland ? Name the gland that performs both endocrine as well as exocrine functions .

Answer : Endocrine glands are organs in the body that secrete hormones directly into the bloodstream to regulate various physiological processes. They include the pituitary gland, thyroid gland, adrenal glands, pancreas, and others.

The difference between endocrine and exocrine glands lies in their mode of secretion. Endocrine glands release hormones directly into the bloodstream, while exocrine glands secrete substances through ducts onto epithelial surfaces or into body cavities.

The pancreas performs both endocrine and exocrine functions. Its endocrine role involves the secretion of hormones such as insulin and glucagon into the bloodstream to regulate blood sugar levels, while its exocrine role involves releasing digestive enzymes into the small intestine through ducts.

Question : What happens in Reflex Actions ?

Answer : Reflex actions are rapid, involuntary responses to stimuli that bypass conscious thought. When a sensory receptor detects a stimulus, a nerve impulse is quickly transmitted to the spinal cord, where it is processed, and a motor response is immediately generated, bypassing the brain's involvement.

Question : How does the nervous tissue cause Action ?

Answer : Nervous tissue triggers action through the transmission of electrical impulses along neurons. When stimulated, a nerve impulse travels down the neuron, reaching the synapse. Neurotransmitters are released, transmitting the signal to the next neuron or target cell. This chain of events results in the execution of specific actions in the body.