CBSE Class 10 Biology Control And Coordination Worksheet Set B

Control and Coordination Notes Class 10 Science

Stimuli: The change in the environment to which an organism responds.

Coordination: Working together of various organs of an organism in a systematic manner to produce a proper response.

Phyto-hormones: These are plant hormones.

Auxin: It is a plant hormone which promotes cell enlargement and growth in plants.

Gibberellins: A plant hormone which promotes cell differentiation and breaking dormancy of seeds and buds.

Cytokinin: A plant hormone which promotes cell division and the opening of stomata.

Abscisic Acid: It helps in inhibiting the growth of the plant and promotes wilting and falling of leaves and food.

Tropism: A growth movement of a plant which determines direction with the stimulus.

Nastism: A growth movement of a plant which does not determine direction with a stimulus.

Phototropism: Movement of plants towards light.

Geotropism: Movement of plants towards the gravity of earth.

Chemotropism: Movement of plants towards chemicals.

Hydrotropism: Movement of plants towards the water.

Thigmotropism: Movement of plants towards a response to the touch of an object

Control and Coordination in Animals

Stimuli: The change in the environment to which the organism responds.

Coordination: Working together of various organs of an organism in a systematic manner to produce a proper response.

Neuron: Functional unit of the nervous system.

Synapse: A microscopic gap between a pair of adjacent neurons.

Receptor: A cell in a sense organ which is sensitive to stimuli.

Motor nerves: It carries the message from the brain to body parts for action.

Sensory nerves: It carries the message from body to brain.

Olfactory receptor: It detects smell by the nose.

Gustatory receptor: It detects taste by a tongue.

Thermoreceptor: It detects heat and cold by a skin.

Photoreceptor: It detects light by eye.

Reflex action: Sudden movement or response to the stimulus which occurs in a very short duration of time and does not involve any will or thinking of the brain.

Brain: An organ present in the skull which controls and regulates the activity of the whole body and is known as president of the body.

Cerebrum: Main thinking part of brain present in the forebrain area which controls all voluntary actions

Cerebellum: It is present in the hindbrain area and helps in maintaining posture and balance of the body.

Medulla: It is present in the hindbrain area and helps in controlling voluntary actions of the brain.

Spinal cord: It is a cylindrical structure of nerve fibres enclosed in the vertebral column which helps in the conduction of nerve impulses to and from the brain.

Important Diagrams and Pictures

Question : How does chemical coordination take place in animals?
Answer : Chemical coordination takes place in animals with the help of hormones. Hormones are the chemical fluids that are secreted by the glands of the endocrine system. Hormones travel through the blood and regulate the overall growth and development of the animals.

Question : How involuntary actions and reflex actions are different form each other? 

Answer : 

 

 

Question. Match the hormones given in column I with their functions given in column II :
        Hormones           Functions
(i) Thyroxine          (a) Causes breasts to develop in females
(ii) Adrenaline        (b) Causes the male to start producing sperms
(iii) Insulin             (c) Prepares the body for an emergency
(iv) Estrogen          (d) Controls the metabolic rate
(v) Testosterone      (e) Regulates the amount of sugar in blood
Answer : (i) d (ii) c (iii) e (iv) a (v) b

Question. A person walks across a room in barefeet and puts his foot on a drawing pin lying on the floor. He lets out a cry. Explain what happens in his nervous system in bringing about this response.
Answer : It is an example of a reflex action. The stimulus in this example is pain which is felt by the foot on touching the drawing pin. This pain is sensed by a receptor in the foot. The receptor triggers an impulse to a sensory neuron which transmits the message to the spinal cord. Here, the impulse is passed on to a relay neuron which, in turn, passes it to a motor neuron. The motor neuron passes the impulse to a muscle in the foot. The muscle, then, contracts and pulls the foot away from the drawing pin.

Question. In what ways are puberty and adolescence result of the activity of some glands in the human body ?
Answer : Puberty and adolescence are results of sex glands in human beings, which is testosterone in males and oestrogen in females.

Question. List three ways in which neurons are similar to other cells.
Answer : Both types of cells have a cell membrane, cytoplasm and a nucleus

Question. Explain the difference between each of the following pairs of terms :
(a) receptor and effector (b) cerebrum and cerebellum
Answer : a) A receptor is an organ or cell able to respond to heat, light or other external stimulus and transmit a signal to a sensory nerve. An effector is a muscle, gland or an organ capable of responding to a stimulus, especially a nerve impulse.
(b) Cerebrum, a part of the forebrain, is responsible for controlling our thoughts, sensations, actions and movements. Cerebellum, a part of the hindbrain, is responsible for maintaining the body posture and balance of the brain.

Question. What is the difference between a voluntary and an involuntary action ? Which kind of action is digestion ? Explain your choice.
Answer : Involuntary action

Question. What does CNS stand for ? Which part of CNS : (a) consists of two cerebral hemispheres, and (b) has spinal nerves attached to it ?
Answer : CNS stands for Central Nervous System.
(a) The cerebrum consists of two cerebral hemispheres.
(b) The spinal cord has spinal nerves attached to it.

Question. Which hormone :
(a) prepares the body for action ?
(b) controls the amount of glucose in blood ?
(c) gives boys a deep voice ?
(d) gives girls soft skin ?
Answer : (a) Adrenaline hormone prepares the body for action.
(b) Insulin hormone controls the amount of glucose in the blood.
(c) Testosterone hormone gives boys a deep voice.
(d) Oestrogen hormone gives girls soft skin.

Question. When you smell a favourite food your mouth begins to water (that is, you secrete saliva). Write down what the following are examples of :
(a) the smell of the food
(b) the cells in your nasal passages which perceive the smell
(c) the gland which is stimulated to secrete saliva.
Answer : (a) Stimulus (b) Receptors (Olfactory receptors) (c) Effector (Salivary gland)

Long Answer Type Questions

Question. (a) Name the structural and functional unit of nervous system.
(b) Draw a flow chart to show the classification of nervous system into various parts.
(c) What is autonomic nervous system ? What is its function ?
(d) What is voluntary nervous system ? Explain the working of voluntary nervous system with an example.
Answer : (a) A neuron is the structural and functional unit of the nervous system.
(b) Classification of the nervous system into various parts:
(c) Autonomic nervous system is the part of nervous system that controls and regulates the functions of internal organs of the body by its own.
Its main function is to control and regulate involuntary body functions like heartbeat, blood flow, breathing and digestion.
(d) Voluntary nervous system is the part of the nervous system that is responsible for carrying motor and sensory information both to and from the central nervous system (CNS). It is associated with voluntary control of body movements through the actions of skeletal muscles. It is also responsible for sensing external stimuli, which helps the body to remain in touch with its surroundings.

Question. (a) What is a reflex action ? Explain with the help of an example.
(b) Define reflex arc. Give the flow chart of a spinal reflex arc.
(c) How are involuntary actions and reflex actions different from each other ?
Answer : a The rapid automatic response to a stimulus which is not under the voluntary action of the brain is called reflex action.Example: Moving our hand away on touching a hot plate.Reflex ActionInvoluntary ActionIt is a rapid automatic response to a stimulus which is not under the voluntary control of the brain.Example:Sneezing coughingThose actions which do not need thinking and are not performed by us knowingly are called involuntary action. Example: Digestion respiration.

Question. (a) What is the function of our nervous system ?
(b) What are the main organs of the human nervous system ? Draw a labelled diagram to show the main organs of the human nervous system.
(c) How does the human nervous system work ? Explain.
Answer : (a) The function of the nervous system is to coordinate the activities of our body. The nervous system helps all the other systems of our body to work together.
(b) The main organs of the human nervous system are the brain, the spinal cord and the nerves.
(c) When the sense organs such as eyes, ears, nose, tongue or skin are affected in our body, they send the message to the brain in the form of electrical impulses through the sensory neurons. The brain analyses this message and decides the action to be taken. The brain, then, sends out instructions to the muscles of the concerned body part through the motor neurons. The concerned body part, then, acts according to the instructions sent by the brain.

Question. (a) What is a neuron ? Draw a labelled diagram of a neuron.
(b) What is a synapse ? What happens at the synapse between two neurons ? How are the messages carried across a synapse ? Explain with the help of a labelled diagram.
Answer : (a) A neuron is a structural and functional unit of the nervous system. A neuron or nerve cell has three components: the cell body, the dendrites and the axon.
(b) Synapses are microscopic gaps present in between pairs of adjacent neurons over which nerve impulses pass from one neuron to the next.

Question. (a) Name two systems which taken together perform the functions of control and coordination in human beings.
(b) What does the central nervous system in humans consist of ? What is the job of the central nervous system ?
(c) Give the various functions of brain.
Answer : (a) The nervous system and the endocrine system together perform the functions of control and coordination in human beings.
(b) The central nervous system consists of the brain and the spinal cord. It is responsible for the coordination and control of the activities of the nervous system. It directs incoming messages to the motor neurons which are connected to the part of the body that will respond to a stimulus.
(c) The various functions of the brain are as follows:
(i) It receives information-carrying nerve impulses from all the sensory organs of the body.
(ii) It responds to the impulses brought in by the sensory organs by sending instructions to the muscles and glands making them function accordingly.
(iii) It correlates the various stimuli from different sense organs and produces the most appropriate and intelligent responses.

Question. (a) Write the names of five endocrine glands found in the human body. Name the hormones secreted by each gland.
(b) How do hormones reach the organs they control ?
(c) Name the gland which controls the secretion of hormones from the pituitary.
(d) How does our body respond when adrenaline is secreted in large amounts into the blood ?
(e) Name the disease which occurs in adults due to the deficiency of iodine in the diet. What is the main symptom of this disease ?
Answer : (a) The five endocrine glands found in the human body are:
Pituitary gland which secretes growth hormone.
Thyroid gland which secretes thyroxine hormone.
Parathyroid gland which secretes parathormone.
Pancreas which secretes insulin.
Adrenal glands which secrete adrenaline.
(b) Hormones reach the target organ through the blood and act on it.
(c) Hypothalamus regulates the secretion of hormones from the pituitary gland.
(d) An increase in the amount of adrenaline in our body increases our heartbeat, breathing rate, blood flow into the muscles and causes the liver to put more stored glucose in our blood. All these actions of adrenaline produce a lot of energy in our body very quickly and enable us to take quick action.
(e) Iodine deficiency in our diet causes goitre. The main symptom of goitre is swelling of the thyroid gland which is present in the neck.

More Question

Question : What is the stimulus in:

a) Phototropism

b) Geotropism

c) Chemotropism

d) Hydrotropism

e) Thigmotropism

Question : Distinguish between tropic and nastic movements of plants

Question : Give one example of the movement of a plant part which is caused by the loss of water

Question : Which plant hormone is responsible for the wilting and falling of leaves?

Question : Differentiate between gigantism & dwarfism

Question : Name one hormone secreted by:

a) Testis

b) Pancreas

c) Thyroid

d) Ovary

Question : What is meant by receptors and effectors ?

Question : Why does reflex action not depend on the thinking tissue in the brain

Question : What happens at the synapse which occurs between the two neurons?

Question : How is the chemical coordination brought about in plants?

Question : With the help of a schematics diagram, trace the sequence of events occurring, when you step on a sharp object. Name this action.

Question : How does our body maintain blood sugar level?

Question : Name the hormone synthesized at the shoot tips. How does it help the plant to respond to light?

Question : What is the function of receptors in human body? What are the types of receptors found in human? What problems are likely to occur if receptors do not work properly?

Question : If you keep the potted plant horizontally for 2‐3 days, what types of movement would be shown by the shoot and root after 2 or 3 days. Why?