Control and Coordination: Class 10 Science Q&A · Page 2
61 free answers on Control and Coordination (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10CBSE
1. Involuntary actions in the body are controlled by (a) medulla in forebrain (b) medulla in midbrain (c) medulla in hindbrain medulla in the spinal cord
Soln: The answer is (c) medulla in hindbrain. Explanation: Medulla is present only in the hindbrain.
- ScienceClass 10CBSE
1. Which of the following statements about the transmission of nerve impulse is incorrect? (a) Nerve impulse travels from the dendritic end towards the 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 A neuron transmits electrical impulses not only to another neuron but also to muscle and gland cells
Soln: The answer is (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. Explanation: Chemicals or neurotransmitters are released at the axonal end, not on the dendritic end. Hence, statement b) is incorrect.
- ScienceClass 10CBSE
1. The substance that triggers the fall of mature leaves and fruits from plants is due to (a) auxin (b) gibberellin (c) abscisic acid cytokinin
Soln: The answer is (c) abscisic acid Explanation: Abscisic acid forms a layer of abscission. This layer disconnects the living tissue of the leaf from the other parts.
- ScienceClass 10CBSE
1. The movement of the sunflower in accordance with the path of the sun is due to (a) phototropism (b) geotropism (c) chemotropism hydrotropism
Soln: The answer is (a) phototropism Explanation: The movement of shoot towards light is called phototropism. Plant growth in response to gravitational force is called geotropism. The growth of plant in response to chemical stimulus is called chemotropism. The growth of plant roots towards or away from moisture is called hydrotropism.
- ScienceClass 10CBSE
1. The growth of pollen tubes towards ovules is due to (a) hydrotropism (b) chemotropism (c) geotropism phototropism
Soln: The answer is (b) chemotropism Explanation: Chemicals released by ovules stimulate the growth of pollen tubes towards ovules.
- ScienceClass 10CBSE
1. The growth of tendril in pea plants is due to (a) effect of light (b) effect of gravity (c) rapid cell divisions in tendrillar cells that are away from the support rapid cell divisions in tendrillar cells in contact with the support
Soln: The answer is (c) rapid cell divisions in tendrillar cells that are away from the support.
- ScienceClass 10CBSE
1. The shape of guard cells changes due to changes in the (a) protein composition of cells (b) temperature of cells (c) amount of water in cells position of the nucleus in the cells
Soln: The answer is (c) amount of water in cells Explanation: Excess of water will turn guard cells turgid, and loss of water will turn guard cells flaccid.
- ScienceClass 10CBSE
1. Select the mismatched pair (a) Adrenaline: Pituitary gland (b) Testosterone: Testes (c) Estrogen: Ovary Thyroxin: Thyroid gland
Soln: The answer is (a) Adrenaline: Pituitary gland Explanation: Adrenaline is secreted by the Adrenal gland, and the Pituitary gland produces TSH, FSH and GSH hormones.
- ScienceClass 10CBSE
1. Choose the incorrect statement about insulin (a) It is produced from pancreas (b) It regulates the growth and development of the body (c) It regulates blood sugar level Insufficient secretion of insulin will cause diabetes
Soln: The answer is (b) It regulates the growth and development of the body
- ScienceClass 10CBSE
1. Iodine is necessary for the synthesis of which hormone? (a) Adrenaline (b) Thyroxin (c) Auxin Insulin
Soln: The answer is (b) Thyroxin
- ScienceClass 10CBSE
1. Which of the following is not associated with the growth of a plant? (a) Auxin (b) Gibberellins (c) Cytokinins Abscisic acid
Soln: The answer is (d) Abscisic acid Explanation: Abscisic acid inhibits the growth of plants; hence, it is not associated with the growth of the plant.
- ScienceClass 10CBSE
1. The main function of abscisic acid in plants is to (a) increase the length of cells (b) promote cell division (c) inhibit growth promote the growth of stem
Soln: The answer is (c) inhibit growth Explanation: Auxins increase the length of cells. Cytokinins promote cell division. Gibberellins promote the growth of the stem.
- ScienceClass 10CBSE
1. The movement of the shoot towards light is (a) geotropism (b) hydrotropism (c) chemotropism phototropism
Soln: The answer is (d) phototropism Explanation: The growth of plant roots towards or away from moisture is called hydrotropism. Plant growth in response to gravitational force is called geotropism. The growth of plants in response to the chemical stimulus is called chemotropism.
- ScienceClass 10CBSE
1. Spinal cord originates from (a) cerebrum (b) medulla (c) pons cerebellum
Soln: The answer is (b) medulla
- ScienceClass 10CBSE
1. Posture and balance of the body is controlled by (a) cerebrum (b) cerebellum (c) medulla pons
Soln: The answer is (b) cerebellum Explanation: Cerebrum is responsible for sensory processing. Medulla controls involuntary functions. Pons regulates respiration and controls involuntary action sensations such as touch and pain.
- ScienceClass 10CBSE
1. Which of the following statements is true about the brain? (i) The main thinking part of the brain is the hindbrain (ii) Centres of hearing, smell, memory, sight etc., are located in the forebrain. (iii) Involuntary actions like salivation, vomiting, and blood pressure are controlled by the medulla in the hindbrain (iv) Cerebellum does not control the posture and balance of the body (a) (i) and (ii) (b) (i), (ii) and (iii) (c) (ii) and (iii) (iii) and (iv)
Soln: The answer is (c) (ii) and (iii) Explanation: Forebrain is the thinking part of the brain hence statement i) is wrong. Cerebellum controls posture and balance of the body hence statement iv) is wrong
- ScienceClass 10CBSE
1. Which of the following statements is true? (i) Sudden action in response to something in the environment is called reflex action (ii) Sensory neurons carry signals from the spinal cord to muscles (iii) Motor neurons carry signals from receptors to the spinal cord (iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called the reflex arc (a) (i) and (ii) (b) (i) and (iii) (c) (i) and (iv) (i), (ii) and (iii)
Soln: The answer is (c) (i) and (iv) Explanation: Sensory neurons carry signals from muscles to the spinal cord hence statements ii) and iv) are wrong statements.
- ScienceClass 10CBSE
1. 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 (c) Receptors → Spinal cord → Sensory neuron → Motor neuron → Muscle (d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle
Soln: The answer is (d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle Explanation: Sensory neurons receive signals from receptors. These signals are sent to the spinal cord, which reaches Muscles through the motor neuron.
- ScienceClass 10CBSE
1. In a neuron, the conversion of electrical signal to a chemical signal occurs at/in (a) cell body (b) axonal end (c) dendritic end axon
Soln: The answer is (b) axonal end Explanation: At the axonal end, the electric impulse triggers the release of neurotransmitters. These chemicals enter the dendrite of another neuron to transmit the signal.
- ScienceClass 10CBSE
1. In a synapse, a chemical signal is transmitted from (a) dendritic end of one neuron to the axonal end of another neuron (b) axon to the cell body of the same neuron (c) cell body to the axonal end of the same neuron axonal end of one neuron to the dendritic end of another neuron
Soln: The answer is (d) the axonal end of one neuron to the dendritic end of another neuron. Explanation: The electric impulse travels from the axon to the dendrite of another neuron through a synaptic gap which consists of SYNAPSE.