MP Board Class 10th Science Solutions Chapter 7 Control and Coordination

MP Board Class 10th Science Solutions Chapter 7 Control and Coordination

MP Board Class 10th Science Chapter 7 Intext Questions

Class 10th Science Chapter 7 Intext Questions Page No. 119

Question 1.
What is the difference between a reflex action and walking?
Answer:
A reflex action is an automatic reaction for each stimulation in our body initiated by our sense responses e.g., we move our hand immediately after a contact with hot object. It is a direct controlled action. Walking is completely controlled by our brain. On the other hand, is a voluntary action. It requires complete coordination of muscles, bones, eyes etc.

Question 2.
What happens at the synapse between two neurons?
Answer:
The electrical impulse travels through axon and sets off the release of some chemicals (neurotransmitters) at the axon endings. These chemicals cross the gap or synapse, and start a similar electrical impulse in a dendrite of the next neuron.

Question 3.
Which part of the brain maintains posture and equilibrium of the body?
Answer:
Cerebellum is the part of the brain which maintains posture and equilibrium of the body.

Question 4.
How do we detect the smell of an agarbatti (incense stick)?
Answer:
Forebrain is responsible for thinking work. It has separate areas that are specialized for hearing, smelling, sight, taste, touch etc. The _ forebrain also has regions that collect information or impulses from various receptors. When the smell of an incense stick reaches us, out forebrain detects it. Then, the forebrain interprets it by putting it together with the information received from other receptors and also with the information already stored in the brain.

Question 5.
What is the role of the brain in reflex action?
Answer:
Reflex actions are sudden responses, which do not involve any thinking. A connection of detecting the signal from the nerves (input) and responding to it quickly (output) is called\a reflex arc. The reflex arcs can be considered as connections present between the input and output nerves which meets in a bundle in the spinal cord. The brain is only responsible of the signal and the response.

Class 10th Science Chapter 7 Intext Questions Page No. 122

Question 1.
What are plant hormones?
Answer:
The chemicals present in plants which help coordinate growth, development and responses to the environment are called plant hormones.

Question 2.
How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?
Answer:

Movement of the leaves of sensitive plant	Movement of shoot towards light
1. The movement is independent of growth	1. The movement depends on growth.
2. Change in the amount of water in the cells of leaves causes the movements.	2. The movement is regulated by plant growth hormones.
3. The movement is fast	3. Shoot movement or stem growth is very slow.

Question 3.
Give an example of a plant hormone that promotes growth.
Answer:
Auxin is a growth-promoting plant hormone.

Question 4.
How do auxins promote the growth of a tendril around a support?
Answer:
A hormone called Auxin, synthesised at the shoot tip helps the cells to grow longer. When light is coming from one side of the plant, auxin diffuses towards the shady side of the shoot. The concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from light. Thus the plant appears to bend towards light.

Question 5.
Design an experiment to demonstrate hydrotropism.
Answer:
Take two small beakers and label them as A and B. Fill beaker A with water. Now, make a cylindrical-shaped roll from a filter paper and keep it as a bridge between beaker A and beaker B, as shown in the figure. Attach few germinating seeds in the middle of the filter paper bridge. Now, cover the entire set-up with a transparent plastic container so that the moisture is retained.

Phenomenon of Hydrotropism Observations:

• The roots of the germinating seeds will grow towards beaker A.
• This experiment demonstrates the phenomenon of hydrotropism.

Class 10th Science Chapter 7 Intext Questions Page No. 125

Question 1.
How does chemical coordination take place in animals?
Answer:
Chemical co-ordination take place by hormones Adrenal gland secrete adrenaline directly into the blood and carried to different parts of the body. Such animal hormones are part of the endocrine system which constitutes a second way of control and coordination in our body.

Question 2.
Why is the use of iodised salt advisable? .
Answer:
Iodine is main stimulator of thyroxine. It stimulates the thyroid gland to produce thyroxine hormone. It regulates carbohydrate, fat and protein metabolism in our body. Deficiency of this hormone results in the enlargement of the thyroid gland. This can lead to goitre, a disease characterized by swollen neck. Therefore, iodised salt is advised for normal functioning of the thyroid gland.

Question 3.
How does our body respond when adrenaline is secreted into the blood?
Answer:
Adrealine is secreted directly into the blood and carried to different parts of the body. The target organs or the specific tissues on which is acts include the heart. As a result, the heart beats faster, resulting in supply of more oxygen to our muscles. The blood to the digestive system and skin is reduced due to contraction of muscles around small arteries in these organs. This diverts the blood to our skeletal muscles. The breathing rate also increases because of the contractions of the diaphragm and the rib muscles.

Question 4.
Why are some patients of diabetes treated by giving injections of insulin?
Answer:
In diabetes, the level of sugar in the blood is too high and hence cause discomfort. Insulin, a naturally occuring chemical inside our pancreas act, as hormones andihelps in regulating the blood sugar levels. When due to very high suga- intake or improper secretion of insulin, balance of insulin decreasesin the body then insulin is injected to body. This is the reason why diabetic patients are treated by giving injections of insulin.

MP Board Class 10th Science Chapter 7 NCERT Textbook Exercises

Question 1.
Which of the following is a plant hormone?
(a) Insulin
(b) Thyroxin
(c) Oestrogen
(d) Cytokinin
Answer:
(d) Cytokinin is a plant hormone.

Question 2.
The gap between two neurons is called a
(a) Dendrite
(b) Synapse
(c) Axon
(d) Impulse
Answer:
(b) The gap between two neurons is called a synapse.

Question 3.
The brain is responsible for:
(a) Thinking
(b) Regulating the heart beat
(c) Balancing the body
(d) All of the above
Answer:
(d) The brain is responsible for thinking, regulating the heart beat and balancing the body.

Question 4.
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
Answer:
Receptors are sensory structures (organs/tissues or cells) present all over the body. The receptors are either grouped in case of eye Or ear, or scattered in case of skin. Functions of receptors:
(i) They sense the external stimuli such as heat or pain.
(ii) They also trigger an impulse in the sensory neuron which sends message to the spinal cord. When the receptors are damaged, the external stimuli transferring signals to the brain are not felt. For example, in the case of damaged receptors, if we accidentally touch any hot object, then our hands might get burnt as damaged , receptors cannot perceive the external stimuli of heat and pain.

Question 5.
Draw the structure of a neuron and explain its function.
Answer:
Neurons are the functional units of the nervous system.
Structure of a Neuron:

The three main parts of a neuron are axon, dendrite and cell body.

Functions of the three parts of a neuron:

1. Axon: It conducts messages away from the cell body. It is the part by which information travels as an electrical impulse.
2. Dendrite: It is the part where information is acquired, it receives information from axon of other cell or initiation point and conducts the messages towards the cell body.
3. Cell body: It is the part where impulse get converted into a chemical signal forwarding transmission. It is mainly concerned with the maintenance and growth.

Question 6.
How does phototropism occur in plants?
Answer:
When growing plants detect light, a hormone called auxin, synthesised at ‘ the shoot tip, helps the cells to grow longer towards light. When light is coming from one side of the plant, Ans: auxin diffuses towards the shady side of the shoot. This concentration of auxin stimulates the cells to grow longer on the side of the shoot which is away from the light. Thus the plant appears to bend towards light, i,e, phototropism.

Question 7.
Which signals will get disrupted in case of a spinal cord injury?
Answer:
Spinal cord is made up of nerves which supply information to think about Nerves from all over the body meet in a bundle in the spinal cord on their way to the brain. Reflex arcs are formed in this spinal cord it self, although the information input also goes on to reach the brain. So if it is injured there is obstruction for carrying impulses to other parts.

Question 8.
How does chemical coordination occur in plants?
Answer:
Different plant hormones help to coordinate growth, development and response to the environment. When growing plants detect light, a hormone called auxin, synthesised at the shoot tip, helps the cells to grow longer. Gibberellins helps in the growth of the stem. Cytokinins promote cell division.

Question 9.
What is the need for a system of control and coordination in an organism?
Answer:
The maintenance of the body functions in response to changes in the body by working together of various integrated body systems is known as coordination. All the movements that occur in response to stimuli are carefully coordinated and controlled. In animals, the control and coordination movements are provided by nervous and muscular systems. The nervous system sends messages to and away from the brain. The spinal cord plays an important role in the relay of messages. In the absence of this system of control and coordination, our body will not be able to function properly. For example, when we accidentally touch a hot utensil, we immediately withdraw our hand. In the absence of nerve transmission, we will not withdraw our hand and may get burnt.

Question 10.
How are involuntary actions and reflex actions different from each other?
Answer:
Involuntary actions cannot be consciously controlled. For example, we cannot consciously control the movement of food in the alimentary canal. These actions are however, directly under the control of the brain. On the other hand, the reflex actions such as closing of eyes immediately when bright light is focussed show sudden response and do not involve any thinking. This means that unlike involuntary actions, the reflex actions are not under the control of brain.

Question 11.
Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.
Answer:
Nervous system mechanism

1. The information is conveyed in the form of electric impulse.
2. The axons and dendrites transmit the information through a coordinated effort.
3. The flow of information is rapid and the response is quick.
4. Its effects are short lived.

Hormonal system mechanism

1. The information is conveyed in the form of chemical messengers.
2. The information is transmitted or transported through blood.
3. The information travels slowly and the response is slow.
4. It has prolonged effects.

Question 12.
What is the difference between the manner in which movement takes place in a sensitive plant and the movement in our legs?
Answer:
In a sensitive plant the cells change shape by changing the amount of water in them, resulting in swelling or shrinking and there fore leading to limited movements. Movement in our legs is voluntary action done by muscle tissue regulated by central nervous system.

MP Board Class 10th Science Chapter 7 Additional Important Questions

MP Board Class 10th Science Chapter 7 Multiple Choice Questions

Question 1.
The brain box which protect internal part of brain is called:
(a) Skull
(b) Peripheral Nervous System
(c) Autonomic Nervous System
(d) Ribs
Answer:
(a) Skull

Question 2.
Secondary sexual characteristics are controlled by:
(a) Central Nervous System
(b) Peripheral Nervous System
(c) Autonomic Nervous System
(d) Endocrine gland
Answer:
(d) Endocrine gland

Question 3.
The activities of the internal organs are controlled by the:
(a) Central Nervous System
(b) Peripheral Nervous System
(c) Autonomic Nervous System
(d) Endocrine glands
Answer:
(a) Central Nervous System

Question 4.
Which pari of brain is the seat of intelligence and voluntary actions?
(a) Diencephalon
(b) Cerebrum
(c) Cerebellum
(d) Medulla oblongata
Answer:
(b) Cerebrum

Question 5.
Cell division in plant is affected by:
(a) Ethylene
(b) Auxin
(c) Gibberellin
(d) Cytokinin
Answer:
(d) Cytokinin

Question 6.
The gap between two neurons is known as……
(a) Synapse
(b) Synopsis
(c) Impulse
(d) Synaptic node
Answer:
(a) Synapse

Question 7.
Which of the follow ing is a plant hormone?
(a) Thyroxin
(b) Cytokinin
(c) Insulin
(d) Oestrogen
Answer:
(b) Cytokinin

Question 8.
Tropic movements are:
(a) In response to light
(b) In response to gravity
(c) Uni-directional
(d) Non – directional
Answer:
(c) Uni-directional

Question 9.
Artifical ripening of fruit is carried out by:
(a) Auxins
(b) Ethylene
(c) Abscisic acid (ABA)
(d) Gibberellins
Answer:
(b) Ethylene

Question 10.
The part of brain that controls respiration, heartbeat and peristalsisis:
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla
Answer:
(d) Medulla

Question 11.
The brain is responsible for:
(a) Thinking
(b) Regulating the heart beat
(c) Balancing the body
(d) All of the above
Answer:
(d) All of the above

Question 12.
Which of the following hormone is released by thyroid?
(a) Insulin
(b) Thyroxine
(c) Trypsin
(d) Pepsin
Answer:
(b) Thyroxine

Question 13.
Which body organ is surrounded by meninges?
(a) Heart and Lungs
(b) Brain and Heart
(c) Brain and Spinal Cord
(d) Spinal Cord and Lungs
Answer:
(c) Brain and Spinal Cord

Question 14.
The part of brain that controls muscular co-ordination is
(a) Cerebrum
(b) Cerebellum
(c) Pons
(d) Medulla
Answer:
(b) Cerebellum

Question 15.
Growth of the stem is controlled by:
(a) Gibberellin
(b) Auxin
(c) Abscisic acid
(d) Cytokinin
Answer:
(a) Gibberellin

Question 16.
Cause wilting of leaves? Which hormone
(a) Gibberellin
(b) Auxin
(c) Abscisic acid
(d) Cytokinin
Answer:
(c) Abscisic acid

Question 17.
Which of the following hormones contains iodine?
(a) Adrenaline
(b) Testosterone
(c) Thyroxine
(d) Insulin
Answer:
(c) Thyroxine

Question 18.
Which part of brain controls the posture and balance of the body?
(b) Cerebellum
(d) Medulla
Ans.
(b)

MP Board Class 10th Science Chapter 7 Very Short Answer Type Questions

Question 1.
What is considered as the structural and functional unit of the nervous system?
Answer:
Neuron or Nerve cell.

Question 2.
What is called an automatic response to a stimulus which is not controlled by the brain?
Answer:
Reflex action.

Question 3.
How do plants respond to stimuli without any kind of nervous systems?
Answer:
Plants respond to stimuli without any kind of nervous systems with the help of plant hormones.

Question 4.
What are the other factors which control and coordinate in plants and animals other than CNS and reflex actions?
Answer:
Hormones.

Question 5.
What is phototropism?
Answer:
The movement of a plant’s part towards light is called phototropism.

Question 6.
What we call to:

1. the movement of plant to the availability of water?
2. the movement of plant to the earth’s gravity?

Answer:

1. Hydrotropism.
2. Geotropism.

Question 7.
Which system of our body is related to hormones which constitutes a second way of control and coordination in our body?
Answer:
Endocrine system.

Question 8.
How many Endocrine glands are situated in our brain? Name them.
Answer:
Three: Hypothalamus, pituitary and pineal glands.

Question 9.
What is considered as the reflex centre of the brain?
Answer:
Medulla oblongata.

Question 10.
Which structure is related to both nervous system and endocrine system in our body?
Answer:
Hypothalamus.

Question 11.
Which part of the brain maintains posture and equilibrium of the body?
Answer:
Cerebellum.

Question 12.
Name the substance important for synthesis of thyroxine.
Answer:
Iodine is essential for the synthesis of thyroxine.

Question 13.
How thyroxine initiate growth in our body?
Answer:
Thyroxine regulates carbohydrate, protein and fat metabolism in our body and provide proper energy which causes the best balance for growth.

Qusestion 14.
Who gave the term phytohormones?
Answer:
Thimann.

MP Board Class 10th Science Chapter 7 Short Answer Type Questions

Question 1.
Write importance of control and coordination in living organisms.
Answer:

• Control and coordination increase the chances of survival by responding to stimuli.
• Different body parts function in coordination to each other as a single unit.

Question 2.
What is hyperglycemia?
Answer:
Hyperglycemia refers to high sugar level in blood. In general, diabetic patients has hyperglycemia due to insufficient release of insulin hormone. .

Question 3.
What are reasons for many drastic changes in appearance at 10-12 years of age?
Answer:
These changes are associated with puberty and are because of the secretion of testosterone in males and oestrogen in females.

Question 4.
Write down the functions performed by cerebrum.
Answer:
The cerebrum performs the following functions:

• It controls our mental abilities like thinking, reasoning, learning, memorising etc.
• It controls our feelings, emotions and speech.
• It controls all involuntary functions.

Question 5.
What are the functions of cerebellum?
Answer:
Functions of cerebellum:

• Maintains equilibrium or balance of the body.
• Coordinates muscular movement.
• Maintains posture of the body.

Question 6.
How soft and delicate brain is safe inside a human body?
Answer:
Brain is placed safely inside a bony box called cranium by the nature, within which there are 3 layers of fluid-filled (called cerebrospinal fluid) membranes (called meninges) which absorb external shock.

Question 7.
What is the role of the brain in reflex action?
Answer:
Brain has no role in reflex action response. Instead, spinal cord is the control center of a reflex action. In fact, brain becomes aware after the reflex arc has been formed.

Question 8.
What do you mean by reflex action? Give examples of reflex actions.
Answer:
It is defined as fast, unconscious, immediate, automatic and involuntary response of the body in parts or total (through effectors) to c «dmulus. It is monitored through spinal cord.

Examples of reflex actions:

• Closing of eyes with bright light.
• Knee-Jerk.
• Withdrawal of body parts when pricked by a pin.

Question 9.
What are the different types of reflexes?
Answer:
There are two types of reflexes:

• Unconditioned reflexes.
• Conditioned reflexes.

Question 10.
What is reflex arc?
Answer:
The structural and functional unit that carries our reflex action is called a reflex arc. It consists of:

• A receptor.
• Sensory nerve (afferent)
• Motor nerve (efferent)
• Spinal cord.
• Inter-neuron and effector

Question 11.
Write important functions of different plant hormones?
Answer:
The five major types of phytohormones and their functions are:

• Auxins: Promote cell division, bending of shoot towards the source of light.
• Cytokinins: Promote cell division.
• Gibberellins: Stimulate stem elongation.
• Abscisic acid: Inhibit growth, closing of stomata and dormancy.
• Ethylene( gas hormone): Promotes fruit ripening and growth.

Question 12.
How is the movement of leaves of the sensitive plant different from the movement of a shoot towards light?
Answer:
The movement of leaves of the sensitive plant, (e.g. Mimosa pudica or touch-me-not) occurs in response to touch or contact stimuli. It is a growth independent movement (nastic movement).

The movement of shoot towards light is called photo-tropism. This type of movement is directional and is growth dependent.

Question 13.
Write some points about the character of nastic movement.
Answer:
Characters of Nastic Movements in plants:

1. Growth independent movements.
2. Time of action – immediate.
3. Response to stimulus – Non-directional.
4. Motive – Change in turgor.

Examples – Folding of leaves of touch-me-not (mimosa).

Question 14.
What is chemotropism?
Answer:
Directional movement of a plant or its part in response to chemicals is called chemotropism, e.g. outward growth of the shoot from origin.

Question 15.
Define geotropism.
Answer:
Roots move in the direction of gravity (positive + ve geotropism).
Shoots move (up) against direction of gravity (negative -ve geotropism).

MP Board Class 10th Science Chapter 7 Long Answer Type Questions

Question 1.
What are the limitations of nervous system in human body? How it is overcomed?
Answer:
A chemical signal in the form of hormones would reach all cells of the body and provide the wide range of changes needed while nervous system in human body works or communicates using nerve impulses which are form of electrical impulses in limited nerve network. Electrical impulses are an excellent means of communication in human body but they have limitations like:

• They reach only those cells that are connected by nervous tissue, not each and every cell in the animal body.
• Cells cannot continually create and transmit electrical impulses.
• Hormone or endocrine system is slower than nerve cells but potentially reach all cells of the body.

Question 2.
Why is the use of iodised salt advised? Why are some patients of diabetes treated by giving injections of insulin?
Answer:
It is advised to use iodised salt to prevent goiter (enlargement of the thyroid gland). Iodine is required for the proper functioning of thyroid. Iodine stimulates the thyroid gland to produce thyroxine hormone. This hormone regulates carbohydrate, fat and protein metabolism in our body. Diabetes is a condition in which sugar level in blood is very high. Insulin hormone is released by pancreas glands which regulates the blood sugar level.

In diabetic patients, pancreas stop releasing insulin hormone. If it is not secreted in proper amounts, the sugar level in the blood rises causing many harmful effects. Due to this reason, diabetic patients are treated by giving injections of insulin. The timing and amount of hormone released are regulated by feedback mechanisms. When the sugar levels in blood rise, they are detected by the cells of the pancreas which respond by producing more insulin. As the blood sugar level falls, insulin secretion is reduced.

Question 3.
How does adrenaline act during emergency?
Answer:
During emergency situations, adrenaline hormone is released into blood stream in large quantities. It increases the heartbeat and hence supplies more oxygen to the muscles. The increase in breathing rate also increases due to contractions of diaphragm and rib muscles. It raises the blood pressure and thus, enable the body to cope up with any stress or emergency. Adrenaline hormone is secreted by the adrenal glands. It helps to regulate heart beat, blood pressure and metabolism in the times of stress or emergency to cope up with the situation.

Question 4.
What happens at the synapse between two neurons?
Answer:
Synapse is a very small gap between the last portion of axon of one neuron and the dendron of the other neuron. It acts as a one way valve to transmit impulses. This is one directional flow of impulses because the chemicals are produced only on one side of the neuron i.e., the axon’s side. Via axon, the impulses travel across the synapse to the dendron of the other neuron.

In total, synapse performs the following tasks:

1. It allows the information to pass from one neuron to another.
2. It ensures the passage of nerve impulse in one direction only.
3. It helps in information processing by combining the effects of all impulses received.

Question 5.
How do we detect the smell of any food?
Answer:
The fore-brain is the main thinking part of the brain. It has regions which receive sensory impulses from various receptors. Separate areas of the fore-brain are specialised for hearing, smell, sight and so on. Olfactoreceptors (present in nose) send the information about the smell of incense stick to fore-brain. The fore-brain interprets it along with information received from other receptors as well as with information that is already stored in the brain.

MP Board Class 10th Science Chapter 7 Textbook Activities

Class 10 Science Activity 7.1 Page No. 115

• Put some sugar in your mouth. How does it taste
• Block your nose by pressing it between your thumb and index finger. Now eat sugar again. Is there any difference in its taste.
• While eating lunch, block your nose in the same way and notice if you can fully appreciate the taste of the food you are eating.

Observations:

• The sugar tastes sweet. The taste is combined perception of tongue and nose.
• When we block our nose, the sugar taste different as now aroma through nose is hindering in proxiding the taste fell earlier. The olfactory receptors of nose are now blocked and we perceixe taste only due to gustatory receptors piesent on tongue.
• Similarly, taste of the food also can not be fully appreciated with blocked nose.

Class 10 Science Activity 7.2 Page No. 121

• Fill a conical flask with water.
• Cover the neck of the flask w’ith a wire mesh.
• Keep two or three freshly germinated bean seeds on the wire mesh.
• Take a cardboard box which is open from one side.
• Keep the flask in the box in such a manner that the open side of the box faces light coming from a window.

• After two or three days, you will notice that the shoots bend towards light and roots away from light.
• Now turn the flask so that the shoots arc away from light and the roots towards light. Leave it undisturbed in this condition for a few days.
• Have the old parts of the shoot and root changed direction?
• Are there differences in the direction of the new growth?
• What can we conclude from this activity?

Observations:

• The old parts of shoot and root does not show’ noticeable changes in the direction.,
• The new’ growth of parts of shoot and root show noticeable changes in the direction of the growth. Shoots bend towards light and roots bend away from it.
• From this activity, we can conclude that shoot shows phototropism and the roots show geotropism.

Class 10 Science Activity 7.3 Page No. 123

• Look at Figure.
• Identify the endocrine glands mentioned in the figure.
• Some of these glands have been listed in Table and discussed in the text. Consult books in the library and discuss with your teachers to find out about other glands.

Endocrine glands in human beings (a) male, (b) female.

Observations:

• The endocrine glands mentioned in the figure are: Hypothalamus, pituitary, pineal, thymus. Thyroid gland, parathyroid, adrenal, pancreas, testes and ovaries.

Class 10 Science Activity 7.4 Page No. 125

• Hormones are secreted by endocrine glands and have specific fifhctions. Complete Table 7.1 based on the hormone, the endocrine gland or the functions provided.

Some important hormones and their functions.

S.No.	Hormone	Endocrine Gland	Functions
1.	Growth hormone	Pituitary gland	Simulates growth in all organs
2.		Thyroid gland	Regulates metabolism for body growth
3.	insulin		Regulated blood sugar level
4.	Testosterone	Testes
5.		Ovaries	Development of female sex organs, regulates menstrual cycle, etc.
6.	Adrenaline	Adrenal gland
7.	Releasing hormones		Stimulates pituitary gland to release hormones

MP Board Class 10th Science Solutions