NCERT Class 10 Science Chapter 7 Notes Control And Coordination- Download PDF Notes

Download NCERT Notes for Class 10 Science Chapter 19 PDF

This chapter explains how our body and other living organisms respond to their surroundings. The concepts are made simple with clear explanations to help revise easily before exams. Students can now download the NCERT notes for class 10 Science chapter 19 PDF. The NCERT Notes for Class 10 Science are a valuable resource for quick and organised study.

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Control and Coordination Class 10 Notes

In this chapter, students will explore how living organisms coordinate and control their actions. The chapter explains the role of the nervous system and hormones in maintaining balance and responding to the environment. Understanding Control and Coordination Class 10 Notes builds a strong base for advanced biology and health science.

Animals - Nervous System

• Nervous and muscular tissues provide control and coordination in animals.
• Environmental changes are detected by specialised tips (dendrites) of some neurons (present in sense organs, i.e., ear, tongue, skin, nose, and eye) by chemical reactions that create electrical impulses.
• This impulse travels through the cell body to the axon of the neuron.
• The nerve impulse is transmitted from one neuron to another through a junction called a synapse.
• Synapses could be electrical synapses or chemical synapses.
• The neuromuscular junction, formed between the neuron and the muscle fibre, transmits nerve impulses to muscle cells.

What Happens in Reflex Actions?

• Reflex actions refer to sudden, involuntary reactions to a stimulus in the environment.
• No thinking in the brain is involved in reflex actions, instead, this quick response is mediated by the reflex arc in the spinal cord.
• The spinal cord is a bundle of nerves on its way towards the brain from all across the body.
• In a reflex arc, a sensory neuron receives a signal from a receptor organ and transmits the impulse via a sensory neuron in the spinal cord, and then to a motor neuron that carries this impulse to the effector organ.
• It can also be perceived as the quickest/ shortest route for an impulse between a receptor to an effector.

Human Brain

• The central nervous system (CNS) is the site for information processing and control. It is constituted by the brain and spinal cord.
• The brain is the main coordinating centre of the body.
• The peripheral nervous system (PNS) facilitates communication between the CNS and the rest of the body.
• Nerves originating from the brain are called cranial nerves, and those from the spinal cord are termed spinal nerves.

The brain has three broad divisions: forebrain, midbrain, and hindbrain.

• The The cerebrum (part of the forebrain) is the biggest section of the brain. It receives sensory impulses from various receptors and is called the main thinking part of the brain.
• It controls all voluntary actions.
• The forebrain has specialised areas for various senses and a separate area for the interpretation of this sensory information by combining data from other receptors and comparing it with existing information stored from past experiences.
• The Hypothalamus (part of the forebrain) is associated with various sensations like hunger.
• The midbrain and hindbrain are responsible for controlling a lot of involuntary actions.
• The medulla (part of the hindbrain) controls involuntary actions, including blood pressure, salivation, and vomiting.
• The cerebellum (part of the hindbrain) maintains body balance and ensures the precision of voluntary actions.

How are These Tissues Protected?

• The brain is protected by the skull, which is a bony structure around the brain.
• Additional shock absorption is provided by the fluid around the brain.
• The spinal cord is protected by the bony vertebral column.

How Does The Nervous Tissue Cause Action?

• Muscle cells contract (shorten) in response to a nerve impulse.
• This change in muscle cells is brought into action by specialised muscle proteins in these cells that change their arrangement in response to an electrical impulse, this new arrangement of proteins shortens the muscle fibre.

Coordination In Plants

• Unlike animals, plants don’t have nervous tissues for control and coordination.
• Leaves of the Chui-mui/touch-me-not plant fold when touched; this movement is independent of growth.
• Growth-dependent movement in plants is seen during seed germination, the roots go down in the soil, and the stem rises in the air.

Immediate Response to Stimulus

• The plants also use electrical-chemical means to convey information from cell to cell.
• Folding leaves of touch-me-not is an immediate response to stimulus (touch/shock), it’s caused by a lowering of turgidity in plant cells.

Movement Due to Growth

• Environmental stimuli like light, gravity, or water can trigger directional growth towards/against the stimulus.
• The bending of plant shoots towards light is called phototropism.
• Plant roots move down the soil in the direction of gravity, this behaviour is termed positively geotropic growth.
• Plants also react to water; hydrotropism, and chemical stimuli; chemotropism, which is seen in pollen tube development in angiosperm ovules.

Electrical vs Chemical Coordination

• Electrical impulses deliver the message very quickly as compared to chemically administered signals, but cells have to be in direct contact with neurons to send/receive impulses.

• An electrical impulse also requires some time to reset before it can transmit the next impulse.
• In chemical coordination, cells release the messenger chemical that will reach its target by diffusion.
• Target cells have special molecules on their plasma membrane to detect the messenger molecule.
• This method of communication is much slower than electrical transmission, but it can be used steadily and persistently.

Plant Hormones

• Similar to animals, plants also use chemicals to communicate between different parts.
• Auxins, gibberellins, and cytokinins are plant-growth-promoting hormones.
• Auxin is synthesised at the shoot apex; it promotes cell elongation. Auxin causes the bending of the shoot towards the light.
• Gibberellins help in stem growth.
• A high concentration of cytokinins is found in areas of active cell division, they promote cell division. Abscisic acid is a plant growth inhibitor hormone that affects the wilting of leaves.

Hormones In Animals

• Chemical signals or hormones reach all cells of the body, unlike neural impulses. As electrical signalling is under the nervous system, chemical messaging is studied under the endocrine system.
• Increased concentration of adrenaline hormone fastens the heartbeat, diverts blood to skeletal muscles, and increases breathing rate. It decreases blood flow to the digestive tract and skin. It prepares the body for emergency response.
• The thyroid gland requires iodine for the formation of the thyroxine hormone. Thyroxin regulates carbohydrate, protein, and fat metabolism in the body. The deficiency of iodine leads to goitre.
• The pituitary gland (located in the brain) secretes multiple hormones, including the growth hormone that is required for proper growth and development.
• Excess or scarcity of growth hormone will result in giantism or dwarfism, respectively.
• On reaching puberty (10-12 age), secretion of estrogen and testosterone hormones starts in the female and male body, respectively.
• Blood glucose level is regulated by the insulin hormone released by the pancreas.

Subject-Wise NCERT Solutions

• NCERT Solution
• NCERT Solutions for Class 10 Maths
• NCERT Solutions for Class 10 Science

Chapter 6 Previous Year Questions and Answers

Some of the questions that have come up in past years from the chapter are given below. To answer these questions, the NCERT Class 10 Science Chapter 6 Notes Control and Coordination acts as a useful guide.

Question 1. Plants use electrical impulses to convey their information from cell to cell. True or False.

Option 1. True

Option 2. False

Answer :

Unlike animals, plants neither have a nervous system nor muscles. Plants use electrical-chemical signals to convey their information from cell to cell. Therefore, the given statement is false.

Hence, the correct option is (2) False

Question 2. The mechanism used by the body to regulate the secretion of hormones is called

Option 1. Hormonal control

Option 2. Hormonal regulation

Option 3. Growth hormone

Option 4. Feedback mechanism

Answer :

A mechanism used by the body to regulate the secretion of hormones is called a feedback mechanism.

Hence, the correct option is (4) Feedback mechanism

Question 3. Which gland secretes the growth hormone?

Option 1. Pituitary gland

Option 2. Thyroid

Option 3. Hypothalamus

Option 4. Adrenal gland

Answer :

Growth hormone is secreted by the pituitary gland. It regulates the growth and development of the body.

Hence, the correct option is (1) Pituitary gland

Benefits of the Class 10 Science Chapter 6 Notes

Studying from the organised notes offers several benefits to students during their exams. Some of them are listed below:

• Class 10 Science Chapter 6 notes can clarify the confusing topics by presenting them in an easy way.

• It allows students to study at their own pace and learning style.

• Having readily available Class 10 Science Chapter 6 notes saves a lot of time during exams.

• A solid understanding of control and coordination helps students to understand the advanced topics effectively.

Chapter-Wise NCERT Class 10 Notes Science

Here are the direct links to access the notes for each of the 13 chapters: