CBSE Class 10 Science Control And Coordination Worksheet Set 10

This is Set 10 of a printable worksheet for CBSE Class 10 Science Chapter 6, Control and Coordination, with true or false statements, fill-ups and short identification questions, each with an answer and a Teacher's Note. It revises the central nervous system, reflex arc, hormones and their glands, deficiency diseases and plant growth regulators.

True or False (State whether each statement is true or false)

Question 1. The central nervous system consists of the brain and spinal cord.
Answer:
Final answer: True.
Reason: The brain and the spinal cord together form the central nervous system (CNS).
In simple words: The CNS is the brain plus the spinal cord.

Teacher's Note:
1. The nerves form the peripheral nervous system.
2. Learn the two divisions together.

Question 2. Chemical coordination is seen in both plants and animals.
Answer:
Final answer: True.
Reason: Plants use phytohormones and animals use hormones from endocrine glands.
In simple words: Both plants and animals use hormones.

Teacher's Note:
1. Only animals also have nervous coordination.
2. Give one hormone from each group.

Question 3. The pathway through which signals are transmitted from a receptor to a muscle is called reflex arc.
Answer:
Final answer: True.
Reason: The route of the nerve impulse from the receptor to the effector in a reflex action is the reflex arc.
In simple words: A reflex arc is the nerve route of a reflex.

Teacher's Note:
1. The pathway goes through the spinal cord.
2. Muscles and glands are the effectors.

Question 4. Thyroxine regulates the blood sugar level.
Answer:
Final answer: False.
Reason: Thyroxine regulates the metabolism of carbohydrates, fats and proteins. The blood sugar level is regulated by insulin.
In simple words: Insulin, not thyroxine, controls the blood sugar.

Teacher's Note:
1. Pair each hormone with its gland and job.
2. Thyroxine needs iodine.

Question 5. The information, acquired at the end of the dendritic tip of a nerve cell, sets off a chemical reaction that creates an electrical impulse.
Answer:
Final answer: True.
Reason: Dendrite tips receive the information and start the electrical impulse, which then travels to the cell body and along the axon.
In simple words: Dendrites receive the information and start the impulse.

Teacher's Note:
1. Order of travel: dendrite, cell body, axon.
2. At the axon end the signal becomes chemical again.

Question 6. Hypothalamus is the main link between nervous system and endocrine system.
Answer:
Final answer: True.
Reason: The hypothalamus, part of the forebrain, controls the pituitary gland by its secretions.
In simple words: The hypothalamus joins the brain with the hormone system.

Teacher's Note:
1. Hypothalamus also controls hunger and thirst.
2. The pituitary is controlled by it.

Question 7. The directional movement of a part of a plant in response to water is called hydrotropism.
Answer:
Final answer: True.
Reason: Roots growing towards water show positive hydrotropism.
In simple words: Growing towards water is hydrotropism.

Teacher's Note:
1. Hydro means water.
2. Roots are positively hydrotropic.

Question 8. Mimosa pudica shows seismonastic movements.
Answer:
Final answer: True.
Reason: Its leaves fold quickly on touch or shock, a non-directional movement without growth.
In simple words: Mimosa leaves fold on touch.

Teacher's Note:
1. Seismonastic and thigmonastic are used for touch responses.
2. It is a nastic movement.

Question 9. Abscisic acid promotes cell division.
Answer:
Final answer: False.
Reason: Cytokinin promotes cell division. Abscisic acid is a growth inhibitor.
In simple words: Cytokinin divides cells and abscisic acid stops growth.

Teacher's Note:
1. Make a table of the five plant hormones.
2. Abscisic acid is the stress hormone.

Fill in the Blanks

Question 10. ________ reduce blood sugar.
Answer:
Final answer: Insulin.
Reason: Insulin from the pancreas helps the cells to take up glucose and the liver to store it, so the blood sugar falls.
In simple words: Insulin brings down blood sugar.

Teacher's Note:
1. The hormone is made by the pancreas.
2. Its lack gives diabetes.

Question 11. ________ inhibit growth in plant.
Answer:
Final answer: Abscisic acid.
Reason: Abscisic acid is the growth inhibitor. It promotes dormancy and the closing of stomata.
In simple words: Abscisic acid is the plant's growth brake.

Teacher's Note:
1. It is also called the stress hormone.
2. Auxin, gibberellin and cytokinin promote growth.

Question 12. Brain is present in ________ which is part of skull.
Answer:
Final answer: Cranium.
Reason: The brain lies in the bony box of the skull called the cranium, which protects it.
In simple words: The brain sits inside the cranium.

Teacher's Note:
1. The spinal cord is protected by the vertebral column.
2. Fluid inside the box acts as a shock absorber.

Question 13. ________ functions are controlled by medulla.
Answer:
Final answer: Involuntary.
Reason: The medulla oblongata controls involuntary actions such as the heartbeat, breathing, blood pressure, vomiting and salivation.
In simple words: The medulla runs the actions that we cannot control.

Teacher's Note:
1. Voluntary actions are controlled by the forebrain.
2. Balance is controlled by the cerebellum.

Name, Identify and Match

Question 14. Answer the following:
(i) A hormone which is called birth hormone in humans.
(ii) Longest cell in the human body.
(iii) Gland located in the neck, just below the larynx.
(iv) The movement in plant which is non-directional.
(v) A plant hormone which causes elongation of cells.
Answer:
(i) Oxytocin.
(ii) Neuron (nerve cell).
(iii) Thyroid gland.
(iv) Nastic movement.
(v) Auxin.
In simple words: Oxytocin, neuron, thyroid, nastic and auxin are the five answers.

Teacher's Note:
1. Revise each term with its definition.
2. Nastic movements do not depend on the direction of the stimulus.

Question 15. Choose the incorrect word from the following and replace it with the correct word:
(i) Pancreas is called the master gland.
(ii) Iron is needed for production of thyroxine.
Answer:
(i) The incorrect word is Pancreas. The pituitary gland is called the master gland, since it controls the other endocrine glands.
(ii) The incorrect word is Iron. Iodine is needed for the production of thyroxine.
In simple words: The master gland is the pituitary, and thyroxine needs iodine.

Teacher's Note:
1. Do not confuse the pancreas, which gives insulin, with the pituitary.
2. Iodine deficiency causes goitre.

Question 16. Which reflex action happens when you:
(A) get dust in your windpipe?
(B) stand out in a cold wind?
Answer:
(A) Coughing, a reflex action that clears the windpipe.
(B) Shivering (and goose bumps), a reflex action that produces heat in the body.
In simple words: Dust makes you cough and cold makes you shiver, without thinking.

Teacher's Note:
1. Reflex actions are quick and automatic.
2. Both are controlled by the central nervous system without the will.

Question 17. Mention the part of the body where gustatory and olfactory receptors are located.
Answer:
The gustatory receptors (for taste) are located in the tongue, and the olfactory receptors (for smell) are located in the nose.
In simple words: The tongue tastes and the nose smells.

Teacher's Note:
1. Gustatory means taste and olfactory means smell.
2. Receptors are found in the sense organs.

Question 18. Discuss the major functions of cytokinin.
Answer:
1. Cytokinins promote cell division, so they are found in greater concentration in areas of rapid cell division, such as fruits and seeds.
2. They delay the ageing of leaves.
3. They promote the opening of stomata.
4. They help to break the dormancy of seeds and buds.
In simple words: Cytokinin is the hormone that makes cells divide.

Teacher's Note:
1. Cytokinin works with auxin in growth.
2. Abscisic acid has the opposite effect on dormancy.

Question 19. Answer the following:
(a) Which hormone is responsible for the changes noticed in females at puberty?
(b) Dwarfism results due to deficiency of which hormone?
(c) Blood sugar level rises due to deficiency of which hormone?
(d) Iodine is necessary for the synthesis of which hormone?
Answer:
(a) Oestrogen, secreted by the ovaries.
(b) Growth hormone, secreted by the pituitary gland.
(c) Insulin, secreted by the pancreas.
(d) Thyroxine, secreted by the thyroid gland.
In simple words: Oestrogen, growth hormone, insulin and thyroxine are the four hormones asked.

Teacher's Note:
1. Write the gland name with each hormone.
2. Dwarfism is caused in childhood.

Question 20. Complete the following.
(a) Acetylcholine : Neurotransmitter :: Adrenaline : ________
(b) Cerebrum : Forebrain :: Cerebellum : ________
(c) Thyroxine : Thyroid gland :: Insulin : ________
(d) Thermoregulation : Hypothalamus :: Body balance : ________
Answer:
(a) Hormone.
(b) Hind brain.
(c) Pancreas.
(d) Cerebellum.
In simple words: Each pair links a thing with its class, part or job.

Teacher's Note:
1. Find the relation in the first pair and apply it to the second.
2. Acetylcholine is a chemical messenger of neurons, and adrenaline is a chemical messenger (hormone) of the adrenal glands.

Teacher's Note:
1. Match the sure pairs first and then the rest.
2. Motor nerves end at the effector organs.