Control and Coordination: Class 10 Science Q&A
61 free answers on Control and Coordination (Science) for Class 10 students, across CBSE, ICSE and State boards. Includes questions such as “What are reflex actions? Give two examples. Explain a reflex arc.”, “What will happen if the intake of iodine in our diet is low?”, “What is a tropic movement? Explain with an example”.
Question & Answer
Questions
- ScienceClass 10CBSE
38. Why is the flow of signals in a synapse from the axonal end of one neuron to the dendritic end of another neuron but not the reverse?
The electrical impulse travels through a neuron. But to be transmitted to another neuron, it needs to be passed in the form of neurotransmitters. Neurotransmitters are specialized chemicals. They can enter a neuron only through specialized channels. Such channels are present in dendrites but not in axons. On the other hand, a neurotransmitter can enter a dendrite. Due to this, the flow of signals in a synapse is from the axonal end of one neuron to the dendritic end of another neuron but not
- ScienceClass 10CBSE
38. “Nervous and hormonal systems together perform the function of control and coordination in human beings.” Justify the statement.
Control and coordination in human beings are under the influence of the nervous system. Brain control all the organelles and organ system. The control is obtained by the network of neurons, which carry signals through neurotransmitters in the form of electric impulses to the brain and from the brain. The hormonal system consists of varieties of hormones secreted by various glands in our body. The hormonal system coordinates the function of the nervous system. Hormones indirectly contr
- ScienceClass 10CBSE
38. What are reflex actions? Give two examples. Explain a reflex arc.
The sudden involuntary movement in a voluntary organ; in response to a stimulus; is called reflex action. Examples of reflex action: Moving your hand away from a hot iron plate Blinking of eyes Reflex Arc. The reflex arc is a path of electrical impulse during a reflex action. It is composed of sensory neurons, the spinal cord, motor neurons and muscles. Steps of the reflex arc</
- ScienceClass 10CBSE
Name various plant hormones. Also, give their physiological effects on plant growth and development.
Soln: Auxin- responsible for the elongation of cells Gibberellin- responsible for the growth of the stem and thereby increases the girth of the stem Cytokinin promotes cell division in plants Abscisic acid stops the growth of the plant, and it makes leaves and fruits fall from the
- ScienceClass 10CBSE
38. Mention one function for each of these hormones : (a) Thyroxin (b) Insulin (c) Adrenaline (d) Growth hormone Testosterone.
Soln: Thyroxin: Thyroxin regulates carbohydrate, protein and fat metabolism in the body so as to provide the best balance for growth. Insulin: Insulin regulates blood glucose levels. If insulin is not secreted at an appropriate level, it leads to a rise in blood glucose level which results in many adverse effects on life processes. Adrenaline: Adrenaline prepares
- ScienceClass 10CBSE
38. What constitutes the central and peripheral nervous systems? How are the components of the central nervous system protected?
Soln: The central nervous system comprises of brain and spinal cord. The peripheral nervous system is composed of nerves which are outside the spinal cord. The central nervous system has a well-developed system for its protection. The brain is enclosed in a hard shell known as the skull. The spinal cord is enclosed in the vertebral column for its protection. Along with these, there is a cerebrospinal fluid which protects the brain from mechanical shocks.
- ScienceClass 10CBSE
38. Answer the following : (a) Name the endocrine gland associated with the brain. (b) Which gland secretes digestive enzymes as well as hormones? (c) Name the endocrine gland associated with kidneys. Which endocrine gland is present in males but not in females?
Soln: Pituitary gland is associated with the The pancreas secretes digestive enzymes as well as Adrenal gland is associated with The testis is present in males but not in
- ScienceClass 10CBSE
38. Answer the following : (a) Which hormone is responsible for the changes noticed in females at puberty? (b) Dwarfism results due to deficiency of which hormone? (c) Blood sugar level rises due to deficiency of which hormone? Iodine is necessary for the synthesis of which hormone?
Soln: Oestrogen hormone is responsible for the changes noticed in females at puberty Dwarfism results due to deficiency of Growth Blood sugar level rises due to deficiency of Insulin Hormone Iodine is necessary for the synthesis of Thyroxine Hormone
- ScienceClass 10CBSE
38. What will happen if the intake of iodine in our diet is low?
Iodine is essential for the synthesis of the hormone thyroxin. If we take a low iodine diet, it leads to hypothyroidism which results in a disease called goitre.
- ScienceClass 10CBSE
What is a tropic movement? Explain with an example
The directional growth movement of a plant due to an external stimulus is called a tropic movement. Movement can be either toward the stimulus or away from the stimulus. For example, roots show positive geotropic movement, and they grow with the direction of gravity, whereas shoots show negative geotropic movement.
- ScienceClass 10CBSE
1. In humans, life processes are controlled and regulated by (a) reproductive and endocrine systems (b) respiratory and nervous systems (c) endocrine and digestive systems nervous and endocrine systems
Soln: The answer is (d) nervous and endocrine systems. Explanation : Reproductive, respiratory and digestive systems have no role to play in the control and regulation of life processes. It is the nervous system and the endocrine system that control and regulates all the processes, including the reproductive, respiratory and digestive systems.
- ScienceClass 10CBSE
1. The junction between two neurons is called (a) cell junction (b) neuromuscular junction (c) neural joint synapse
Soln: The answer is (d) synapse Explanation: A synapse is a structure that allows a neuron to pass an electric signal to the next neuron or effector cell. Hence it is a junction between two neurons.
- ScienceClass 10CBSE
1. Which of the following endocrine glands is unpaired? (a) Adrenal (b) Testes (c) Pituitary Ovary
Soln: The answer is (c) Pituitary Explanation: Adrenal glands are two, which are present on top of each kidney. Testes is a paired gland in males which produces male sex hormones. Ovary is a paired gland in females which produces female sex hormones. The pituitary gland is an independent gland present below the brain. It is called as master gland, as it secretes major of the hormones.
- ScienceClass 10CBSE
1. The hormone which increases fertility in males is called (a) oestrogen (b) testosterone (c) insulin growth hormone
Soln: The answer is (b) testosterone
- ScienceClass 10CBSE
A doctor advised a person to take an injection of insulin because (a) his blood pressure was low (b) his heart was beating slowly (c) he was suffering from goitre (d) his sugar level in blood was high
Patients suffering from diabetes will have high blood glucose due to non-functioning or lack of insulin hormone. Such patients are administered with insulin injections to regulate blood glucose.The answer is (d)
- ScienceClass 10CBSE
1. Dramatic changes of body features associated with puberty are mainly because of the secretion of (a) oestrogen from testes and testosterone from ovary (b) estrogen from adrenal gland and testosterone from pituitary gland (c) testosterone from testes and estrogen from ovary testosterone from thyroid gland and estrogen from pituitary gland
Soln: The answer is (c) testosterone from testes and estrogen from ovary. Explanation: These are the sex hormones responsible for the secondary character that appear after puberty. Males secrete testosterone, and females secrete estrogen.
- ScienceClass 10CBSE
1. Dwarfism results due to (a) Excess secretion of thyroxin (b) Less secretion of growth hormone (c) Less secretion of adrenaline Excess secretion of growth hormone
Soln: The answer is (b) Less secretion of growth hormone Explanation: Growth hormones are responsible for the overall growth of an organism. When there is no secretion of growth hormones, it leads to dwarfism.
- ScienceClass 10CBSE
1. 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 (c) The thyroid gland requires iodine to synthesise thyroxin Thyroxin is also called the thyroid hormone
Soln: The answer is (a) Iron is essential for the synthesis of thyroxin Explanation: Iodine is essential for the synthesis of thyroxin but not iron hence statement a) is wrong
- ScienceClass 10CBSE
1. 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 (c) differentiate red light from green light differentiate a hot object from a cold object
Soln: The answer is (b) differentiate the smell of a perfume from that of an agarbatti. Explanation: During cold olfactory receptors get blocked hence we cannot differentiate smell.
- ScienceClass 10CBSE
1. Which of the following is not an involuntary action? (a) Vomiting (b) Salivation (c) Heartbeat Chewing
Explanation: The answer is (d) Chewing