ROUTERA

Control and Coordination

Class 10th Science Chapter Assertion and Reason

Control and Coordination

  • Options:
    a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
    b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    c) Assertion (A) is true, but Reason (R) is false.
    d) Assertion (A) is false, but Reason (R) is true.

 

Question 1

Assertion (A): The nervous system is responsible for controlling body functions.
Reason (R): The nervous system coordinates voluntary and involuntary actions in the body.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The nervous system processes information from sensory organs and coordinates responses, controlling both voluntary (e.g., movement) and involuntary (e.g., heartbeat) actions.

Question 2

Assertion (A): Hormones act as chemical messengers in the body.
Reason (R): Hormones are produced by endocrine glands and travel through the bloodstream to target organs.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Hormones are secreted by endocrine glands and regulate various physiological processes by transmitting signals to specific organs via the bloodstream.

Question 3

Assertion (A): The human brain is divided into three main parts.
Reason (R): The brain consists of the cerebrum, cerebellum, and brainstem, each serving distinct functions.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The brain's division into cerebrum, cerebellum, and brainstem allows it to perform complex functions like thought, coordination, and vital functions.

Question 4

Assertion (A): Reflex actions are rapid responses to stimuli.
Reason (R): Reflex actions involve direct pathways called reflex arcs that bypass the brain.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Reflex actions are processed quickly via spinal cord pathways, allowing immediate reactions without involving the brain for quicker responses to harmful stimuli.

Question 5

Assertion (A): The endocrine system regulates slower but longer-lasting responses compared to the nervous system.
Reason (R): Hormones released into the bloodstream take time to produce effects on target tissues.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Hormones travel through the bloodstream and can take minutes to hours to exert their effects, leading to prolonged responses in comparison to the rapid signals of the nervous system.

Question 6

Assertion (A): The synapse is the junction between two neurons.
Reason (R): Neurotransmitters are released at the synapse to transmit signals between neurons.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The synapse allows for communication between neurons through neurotransmitters, facilitating signal transmission in the nervous system.

Question 7

Assertion (A): The cerebellum is responsible for balance and coordination.
Reason (R): The cerebellum processes information from the inner ear and muscles to maintain posture.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The cerebellum integrates sensory input and fine-tunes motor activity, playing a critical role in maintaining balance and coordination of movements.

Question 8

Assertion (A): Phototropism is the growth of a plant in response to light.
Reason (R): Auxins are hormones that promote growth in plant cells on the side away from light.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Auxins cause cells on the shaded side of a plant to elongate more than those on the lighted side, resulting in the plant bending towards the light.

Question 9

Assertion (A): The hypothalamus regulates body temperature and hunger.
Reason (R): The hypothalamus is part of the brain that maintains homeostasis.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The hypothalamus is crucial for maintaining homeostasis by regulating various bodily functions, including temperature and hunger signals.

Question 10

Assertion (A): Hormones can have multiple effects on different tissues.
Reason (R): Different tissues may have receptors for the same hormone, leading to varied responses.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: A single hormone can bind to different receptors in various tissues, causing diverse physiological responses based on the target tissue type.

Question 11

Assertion (A): The medulla oblongata controls involuntary actions such as heartbeat and breathing.
Reason (R): The medulla oblongata is the lowest part of the brain and is crucial for vital functions.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The medulla oblongata autonomously regulates vital involuntary functions like heart rate and respiration, making it essential for survival.

Question 12

Assertion (A): The pituitary gland is often called the "master gland."
Reason (R): The pituitary gland regulates the function of other endocrine glands.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The pituitary gland produces hormones that control the activity of other endocrine glands, influencing various physiological processes.

Question 13

Assertion (A): The sensory neurons carry signals from the body to the brain.
Reason (R): Sensory neurons are responsible for transmitting sensory information to the central nervous system.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Sensory neurons relay information from sensory receptors to the brain, allowing the body to process stimuli from the environment.

Question 14

Assertion (A): Insulin regulates blood sugar levels.
Reason (R): Insulin is produced by the pancreas in response to high blood glucose levels.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Insulin helps lower blood sugar levels by promoting the uptake of glucose by cells, thus regulating glucose homeostasis.

Question 15

Assertion (A): A reflex action is faster than a voluntary action.
Reason (R): Reflex actions involve fewer neurons in their pathway than voluntary actions.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Reflex actions involve simple reflex arcs, allowing quicker responses to stimuli compared to the more complex pathways of voluntary actions.

Question 16

Assertion (A): The sympathetic nervous system is responsible for the "fight or flight" response.
Reason (R): The sympathetic nervous system prepares the body for stressful situations by increasing heart rate and energy mobilization.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The sympathetic nervous system activates physiological changes that prepare the body to respond to stress, enhancing alertness and physical readiness.

Question 17

Assertion (A): The autonomic nervous system regulates voluntary movements.
Reason (R): The autonomic nervous system controls involuntary bodily functions like heart rate and digestion.

  • Answer: b) Assertion (A) is false, but Reason (R) is true.
  • Explanation: The autonomic nervous system primarily regulates involuntary functions, while voluntary movements are controlled by the somatic nervous system.

Question 18

Assertion (A): The role of the pancreas is limited to digestion.
Reason (R): The pancreas also has an endocrine function by producing insulin and glucagon.

  • Answer: b) Assertion (A) is false, but Reason (R) is true.
  • Explanation: The pancreas performs both exocrine functions (digestion) and endocrine functions (regulating blood sugar levels through hormone production).

Question 19

Assertion (A): The cerebral cortex is involved in higher brain functions.
Reason (R): The cerebral cortex is responsible for processing sensory information and coordinating voluntary movements.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The cerebral cortex is crucial for cognitive functions, including perception, reasoning, and decision-making, in addition to coordinating voluntary movements.

Question 20

Assertion (A): The human eye can distinguish millions of colors.
Reason (R): Cones in the retina are responsible for color vision and function best in bright light.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Cones are photoreceptors in the retina that enable color vision by detecting different wavelengths of light, allowing us to perceive a wide range of colors.