Control and Coordination - Class 10 Science - Chapter 6 - Notes, NCERT Solutions & Extra Questions
Renews every month. Cancel anytime
Your personal doubt-solving assistant
Chatterbot AI gives you 100% accurate answers to your questions in an instant.
Notes - Control and Coordination | Class 10 NCERT | Science
Understanding control and coordination is crucial for mastering biology in Class 10. This article offers a detailed overview of how living organisms regulate and coordinate their functions, focusing on both nervous and hormonal mechanisms. Let's dive in!
Control and Coordination in Animals
Nervous System
The nervous system is the primary control and coordination center in animals. It consists of the brain, spinal cord, and nerves. This complex network allows animals to detect environmental changes and respond appropriately.
Structure and Function of Neurons
Dendrites: Receive signals from sensory receptors.
Cell Body: Processes incoming signals.
Axon: Transmits signals to other neurons or muscles.
Signal Transmission: Neurons communicate through electrical impulses that travel along the axon. When the impulse reaches the end of the axon, it triggers the release of chemicals across the synapse, transmitting the signal to the next neuron.
Reflex Actions and Reflex Arc
Reflex actions are rapid, involuntary responses to stimuli, such as pulling your hand away from a hot object. Reflex arcs are pathways that facilitate these actions, allowing for quick responses without involving the brain.
Human Brain
The human brain is the main coordinating center and is divided into three major parts:
Fore-brain: Responsible for complex thinking, memory, and sensory information processing.
Mid-brain: Controls vision and hearing responses.
Hind-brain: Manages balance, movement, and involuntary actions like heartbeat and breathing.
Protection: The brain is protected by the skull and cushioned by cerebrospinal fluid. The spinal cord, encased in the vertebral column, serves as a conduit for signals between the brain and the rest of the body.
Voluntary vs Involuntary Actions
Voluntary Actions: Controlled consciously, such as walking and talking.
Involuntary Actions: Automatic functions, like heartbeat and digestion, managed by the mid-brain and hind-brain.
Control and Coordination in Plants
Plant Movements
Plants lack a nervous system but still respond to stimuli through chemical means. They exhibit two main types of movements:
Growth-dependent: e.g., bending towards light (phototropism).
Growth-independent: e.g., the rapid closing of 'touch-me-not' leaves.
Plant Hormones
Auxins: Promote stem elongation and are crucial for phototropism.
Gibberellins: Stimulate stem growth.
Cytokinins: Promote cell division.
Abscisic Acid: Inhibits growth and promotes leaf fall.
Tropic Movements
Phototropism: Shoots bend towards light, enhancing photosynthesis.
Geotropism: Roots grow downward responding to gravity.
Hydrotropism & Chemotropism: Roots grow towards water and nutrients, respectively.
Hormonal Coordination in Animals
Endocrine System
Hormones, secreted by endocrine glands, regulate numerous body functions. Major glands include the pituitary, thyroid, adrenal, and pancreas, each producing specific hormones crucial for the body's function.
Role of Hormones
Adrenaline: Prepares the body for 'fight or flight' situations by increasing heart rate and blood supply to muscles.
Insulin: Regulates blood sugar levels, produced by the pancreas.
Thyroxin: Regulates metabolism, produced by the thyroid gland.
Growth Hormone: Controls growth and development, secreted by the pituitary gland.
Feedback Mechanisms
Hormone levels are controlled by feedback mechanisms. For instance, high blood sugar levels trigger insulin release. Once the sugar level drops, insulin secretion decreases, maintaining balance.
Conclusion
Control and coordination are vital for the survival and proper functioning of living organisms. While nervous systems facilitate quick responses in animals, plants rely on hormonal signaling for growth and adaptation. Understanding these processes provides a comprehensive insight into how life is intricately balanced.
🚀 Learn more about Notes with Chatterbot AI
Extra Questions - Control and Coordination | NCERT | Science | Class 10
💡 Have more questions?
Ask Chatterbot AINCERT Solutions - Control and Coordination | NCERT | Science | Class 10
Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxin
(c) Oestrogen
(d) Cytokinin.
(d) Cytokinin is a plant hormone. The other options, (a) Insulin, (b) Thyroxin, and (c) Oestrogen, are hormones found in animals. Cytokinins are involved in various aspects of plant growth and development, including cell division and differentiation, and the regulation of other physiological processes.
The gap between two neurons is called a
(a) dendrite.
(b) synapse.
(c) axon.
(d) impulse.
The gap between two neurons is called a synapse. So, the correct answer is:
(b) synapse.
The brain is responsible for
(a) thinking.
(b) regulating the heart beat.
(c) balancing the body.
(d) all of the above.
The brain is responsible for:
(d) all of the above.
It is involved in thinking processes as the center for processing information and controlling cognitive functions.
It regulates the heart rate through the autonomic nervous system, specifically the brainstem and hypothalamus.
It is important for balancing the body by coordinating information from the vestibular system, which deals with balance, and processing that information to maintain posture and equilibrium.
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
Receptors in the human body serve an essential role as molecular detectors that interpret various signals from the external environment or from other cells. These signals can include hormones, neurotransmitters, and sensory stimuli such as light, sound, and touch. By binding to specific ligands, receptors trigger a cellular response that can influence various bodily functions including movement, mood, immune responses, and sensory perception.
When receptors do not work properly due to mutations, disease, or blockage, it can lead to a myriad of problems. For instance, malfunctioning insulin receptors can lead to diabetes by impairing the body's ability to regulate blood sugar levels. Similarly, defective neurotransmitter receptors may contribute to neurological disorders such as schizophrenia or Parkinson's disease by disrupting communication between nerve cells. Additionally, faulty sensory receptors could impair vision, hearing, taste, or smell, significantly affecting quality of life. Understanding and addressing receptor malfunctions is therefore critical in medical diagnostics and treatment.
Draw the structure of a neuron and explain its function.
A neuron, also known as a nerve cell, is the basic working unit of the brain and the nervous system. Neurons are specialized to transmit information throughout the body. The key parts of a neuron include the following:
Cell Body (Soma): Contains the nucleus and is responsible for maintaining the life of the cell.
Dendrites: Branch-like structures that receive messages from other neurons and transmit them toward the cell body.
Axon: A long, thin structure that transmits messages away from the cell body to other neurons, muscles, or glands.
Myelin Sheath: A fatty material that encases the axon of many neurons, which helps speed up neural transmission.
Axon Terminals (Synaptic Boutons): The ends of the axon that contain neurotransmitters, which are chemicals that can convey the signal across a synapse to another cell.
Synapse: The small gap between the axon terminals of one neuron and the dendrites or cell body of another neuron.
The function of neurons is to process and transmit information through electrical and chemical signals. When a neuron receives a signal, if the signal is strong enough, it triggers an action potential—an electrical charge that travels down the axon to the synapse where it leads to the release of neurotransmitters. These neurotransmitters then cross the synapse to the next neuron, muscle, or gland, thereby continuing the transmission of information.
How does phototropism occur in plants?
Phototropism is the growth response of a plant in relation to the direction of light. This phenomenon allows plants to grow towards a light source, optimizing their exposure to sunlight, which is crucial for photosynthesis. The primary mechanism behind phototropism involves the hormone auxin, which regulates plant growth. When light shines on a plant from one direction, auxin accumulates on the shadier side of the plant, leading to faster growth on that side. This differential growth causes the plant to bend towards the light. The tip of the plant, particularly the coleoptile in grass seedlings, is where light is sensed and where auxin production is initially influenced. The redistribution of auxin to the shaded side then stimulates elongation of cells, causing the plant to tilt towards the light source. This adaptation not only maximizes light capture for photosynthesis but also helps young shoots to emerge from under the soil by growing towards the light.
Which signals will get disrupted in case of a spinal cord injury?
Spinal cord injuries can disrupt the transmission of signals between the brain and parts of the body below the injury site. The spinal cord acts as the main pathway for information to travel between the brain and the nervous system. When an injury occurs, it can interfere with this communication by either partially or completely severing the connections. This can lead to loss of motor function, sensory function, or both below the level of the injury. Motor function disruption results in paralysis, affecting movement and muscle control. Sensory function disruption leads to a loss of feeling or sensation. Additionally, spinal cord injuries can affect autonomic functions such as blood pressure, temperature regulation, and bladder and bowel control, depending on the severity and location of the injury.
How does chemical coordination occur in plants?
Chemical coordination in plants happens through substances called hormones. In both plants and animals, hormones are produced in one part of the organism and move to another part to achieve the desired effect. In plants, these hormones are involved in different physiological processes, including growth, development, and reactions to environmental changes. A feedback mechanism regulates the action of these hormones to ensure that they are present in precise quantities when and where they are needed.
What is the need for a system of control and coordination in an organism?
The need for a system of control and coordination in an organism is crucial because organisms must be able to respond appropriately to various environmental stimuli. Controlled movement is necessary so that each kind of change in the environment evokes an appropriate response. For example, when bright light is focused on our eyes or when we touch a hot object, we detect the change and respond with movement to protect ourselves.
Control and coordination are accomplished through the use of specialized tissues in multicellular organisms, particularly the nervous and muscular tissues. The nervous tissue is organized into a network of nerve cells, or neurons, which are specialized for conducting information via electrical impulses. The process of detection and response requires the integration of signals from receptors located in our sense organs, which are processed by the nervous system to evoke the necessary response.
Reflex actions are a prime example of this system at work, allowing for quick responses to potentially harmful stimuli without the need for conscious thought, an advanced level of control and coordination that has evolved for efficiency and protection.
How are involuntary actions and reflex actions different from each other?
Involuntary actions and reflex actions are both types of actions that occur in our bodies without our conscious decision-making. However, there is a difference between the two:
Involuntary actions are those that occur without our conscious control, such as the beating of the heart, the movement of food through the digestive system, or the dilation and constriction of our pupils in response to light intensity. These are continuous and necessary for survival.
Reflex actions, on the other hand, are sudden and automatic responses to stimuli that bypass the brain. Examples include quickly withdrawing a hand from a hot surface or the knee-jerk reflex. Reflex actions are typically protective mechanisms that help prevent injury. They involve a simple neural pathway called a reflex arc that goes through the spinal cord and may not necessarily engage the brain for decision-making.
Please note that I found the question in the textbook, but the specific details elaborating on the differences were not available in the provided section. The explanation I have given you is based on generally accepted biological knowledge.
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Here is a comparison and contrast between nervous and hormonal mechanisms for control and coordination in animals, presented in a table format:
Aspect | Nervous System | Hormonal System (Endocrine System) |
---|---|---|
Speed of Response | Fast, responses can occur within milliseconds. | Slower, responses can take from seconds to minutes or even days to manifest. |
Duration of Response | Short-lived, effects often cease once the stimulus is removed. | Prolonged, effects can last from a few minutes to several days, even after the stimulus has ceased. |
Mode of Transmission | Electrical impulses along neurons and chemical neurotransmission at synapses. | Chemical hormones are secreted into the bloodstream, affecting target cells throughout the body. |
Specificity of Action | Highly specific, targeting precise areas of the body due to the organization of neural pathways. | Generally widespread, as hormones can affect any cell with the corresponding receptor, potentially leading to effects in multiple areas of the body. |
Control of Action | Can facilitate both voluntary and involuntary responses, allowing for immediate reaction to the environment. | Primarily involuntary, regulating long-term processes such as growth, metabolism, and reproduction. |
Mechanism of Signal | Signals are transmitted via a complex network of neurons. | Signals are transmitted through the circulatory system by hormones. |
Integration | The central and peripheral nervous systems integrate and process information rapidly to produce an immediate response. | Hormones influence the intensity and duration of responses and integrate activities of different systems over longer periods. |
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
The movement in a sensitive plant, such as Mimosa pudica, is an example of a nastic movement which is caused by changes in turgor pressure within the plant cells, leading to a rapid collapse or movement of the plant parts without the plant moving towards or away from a stimulus. This type of movement is non-directional and is triggered by stimuli such as touch.
On the other hand, the movement in our legs involves muscular contractions controlled by the nervous system. This is a voluntary movement that is directional and purpose-driven, allowing humans to move towards or away from stimuli. It involves a complex interaction between muscles, bones, and nerves, with energy provided by cellular metabolism.
Thus, the primary difference lies in the mechanisms and purposes of these movements: turgor pressure-induced changes in plants versus nervous system-controlled muscle contractions in humans.
💡 Have more questions?
Ask Chatterbot AIExtra Questions and Answers - Control and Coordination | NCERT | Science | Class 10
Arrange the following activities in the order of decreasing speed in which they take place:
(i) Movement of mimosa when it is touched.
(ii) Movement of sunflower in response to day and night.
(iii) Growth-related movements of plants.
A) (ii) - (iii) - (i)
B) (i) - (ii) - (iii)
C) (iii) - (ii) - (i)
D) (iii) - (i) - (ii)
The correct answer is Option B: (i) - (ii) - (iii)
The movement of the mimosa plant's leaves, which close and droop down swiftly upon being touched, occurs at the fastest rate among the listed activities.
The sunflower's movement in response to the sun's position across day and night takes place at a slower rate compared to the rapid reaction of the mimosa plant.
Finally, growth-related movements in plants generally occur at the slowest pace, as these are gradual changes that take place over longer periods.
In summary, the speed of these movements decreases from the immediate response of mimosa (i), to the day-long tracking of the sun by sunflowers (ii), ending with the gradual growth movements of plants (iii).
Any change in the environment to which an organism responds is called
A) stimulus
B) response C) tropism
D) dominance
The correct answer is A) stimulus.
A stimulus is any change in the environment that elicits a response from an organism. A response is how an organism reacts to a stimulus. Tropism refers to a directional growth movement in response to an environmental stimulus. Dominance, such as apical dominance, involves the suppression of growth in certain parts of a plant, often influenced by hormonal factors.
Parasympathetic nervous system is responsible for
A. flight/fight actions.
B. quick response.
C. acceleration of heart rate.
D. calming down the body.
The correct answer is D. calming down the body.
The autonomic nervous system is divided into two main components:
Sympathetic nervous system
Parasympathetic nervous system
These two systems perform opposite functions and work together to maintain balance in the body's involuntary functions. The parasympathetic nervous system acts primarily to relax, conserve energy, and slow down bodily functions. In contrast, the sympathetic nervous system prepares the body for intense physical activity (often referred to as "fight or flight" responses) by accelerating heart rate and increasing glucose production. Thus, tasks such as lowering the heartbeat and decreasing glucose production fall under the control of the parasympathetic nervous system.
Which of the following skills are required for playing a sport?
A. Concentration B. Physical strength C. Team coordination D. All of the above.
The correct option is D. All of the above.
Sports encompass a wide range of skills to play effectively. Concentration is crucial as it helps athletes to focus on their strategies and performance during the game. Physical strength is also essential because it enhances the ability to endure and excel in physical activities. Furthermore, team coordination plays a critical role, especially in team sports, where synchronizing with teammates can be the deciding factor for winning. Thus, all these skills are integral to playing and succeeding in sports.
Which of the following agencies are in contact with the district control unit during a disaster?
A) Army
B) Navy
C) Telecommunication department
D) All of the above
The correct answer is D) All of the above.
During a disaster, a district control unit is swiftly established to manage the situation effectively. This unit is crucial for quickly reviewing the situation and coordinating response efforts. It involves multiple agencies to ensure an efficient and comprehensive response. Key agencies include the Army, Navy, and Telecommunication Department among others, as they play essential roles in managing and mitigating the effects of the disaster. Thus, all the mentioned options (Army, Navy, and Telecommunication department) are in contact with the district control unit during a disaster.
Vagus nerve is
A) Motor nerve
B) Sympathetic nerve
C) X cranial nerve
D) V cranial nerve
The correct answer is C) X cranial nerve.
The vagus nerve is the longest cranial nerve. It contains both motor and sensory fibers and has the widest distribution in the body as it passes through the neck, thorax, and abdomen.
Which one of the following represents the correct sequence of reflex action?
A. Receptor $\rightarrow$ sensory nerve $\rightarrow$ motor nerve $\rightarrow$ muscle
B. Receptor $\rightarrow$ sensory nerve $\rightarrow$ spinal cord $\rightarrow$ motor nerve $\rightarrow$ muscle
C. Receptor $\rightarrow$ sensory nerve $\rightarrow$ spinal cord $\rightarrow$ motor nerve $\rightarrow$ muscle
D. Receptor $\rightarrow$ motor nerve $\rightarrow$ spinal cord $\rightarrow$ sensory nerve $\rightarrow$ muscle
A reflex action is an automatic response generated without conscious thought, mainly to protect the body from harm. For instance, if you touch something hot, your body will immediately respond to prevent injury. This automatic response follows a specific sequence within the nervous system.
Receptor: The process initiates when a receptor, located in the skin, senses a stimulus such as a temperature change. This change triggers an impulse.
Sensory Nerve: The impulse is then transmitted to sensory nerves. Sensory nerves are responsible for detecting and carrying the signals from the sensory receptors. By detecting the stimulus, the sensory nerves send the information further to the central nervous system.
Spinal Cord: Upon reaching the spinal cord, the signal is handed over to relay neurons. These relay neurons serve as intermediaries within the spinal cord, connecting sensory nerves to motor nerves.
Motor Nerve: After the relay neurons transfer the signals, they reach the motor nerves. Motor nerves are tasked with generating an appropriate action or movement in response to the original stimulus.
Muscle (Effector): Finally, the signal reaches the muscle or effector, which reacts accordingly. For instance, pulling your hand away from the hot object is an effect orchestrated by the muscles.
Therefore, according to the process described:
The correct sequence of a reflex action is: Receptor $\rightarrow$ Sensory Nerve $\rightarrow$ Spinal Cord $\rightarrow$ Motor Nerve $\rightarrow$ Muscle.
This corresponds to option B in the original question choices: $$ \text{Receptor} \rightarrow \text{Sensory Nerve} \rightarrow \text{Spinal Cord} \rightarrow \text{Motor Nerve} \rightarrow \text{Muscle} $$
This organ controls the reflex actions:
A. Spinal Cord
B. Heart
C. Liver
D. Kidney
To identify the correct organ, it’s essential to understand what a reflex action is. Reflex actions are sudden and involuntary responses to stimuli.
From the options given:
The spinal cord is crucial because it acts as a bridge transferring nerve signals between the brain and the body. It plays a pivotal role in handling reflex actions without the brain's direct involvement.
The heart primarily functions by pumping blood through the cardiovascular system.
The liver and kidney serve various metabolic and excretory functions, respectively.
Given these roles, the correct answer is option A, the Spinal Cord. This organ is deemed crucial for controlling reflex actions because it processes and effects reflex responses directly and swiftly by sending signals along the nerves. This operation allows the body to react rapidly to certain stimuli, bypassing the slower, conscious responses that involve the brain, which is critical for protection and fast reaction in hazardous situations. This makes the spinal cord indispensable for automatic and protective responses.
💡 Have more questions?
Ask Chatterbot AI