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Chapter 6 Control and Coordination Class 10 Science Important Questions and Answers are considered perfect as they take into account all the guidelines and criteria set by the CBSE board for evaluating students’ answers. The Gkrankers experts have put in a lot of effort to prepare solutions that are aligned with the CBSE marking schemes.

Students can rely on Chapter 6 Class 10 Science Extra Questions to understand the expected format, content, and approach required to score well in their CBSE exams.

Chapter 6 Control and Coordination Important Questions and Answers Class 10 Science

Chapter 6 Control and Coordination Very Short Questions and Answers

1. What is tropism?


The directional movement of the plant part towards or away from the stimulus is called tropism.

2. Define phototropism.


The movement or bending of the shoot towards the direction of light is called phototropism.

3. State the main functions of abscisic acid in plants.


Abscisic acid inhibits the growth of plants.

4. Name two tissues that provide control and coordination in multicellular animals.


The two tissues that provide control and coordination in multicellular animals are nervous tissue
and muscular tissue.

5. Which hormone controls the metabolism of calcium and phosphorus in human beings?


Parathyroid hormone

6. Name the hormones in humans which regulates carbohydrate, protein and fat metabolism in the body. Mention the site where it is synthesized.


The hormone is thyroxin. The site where it is synthesized is thyroid gland.

7. Name the two components of peripheral nervous system.


Cranial nerves arising from the brain and the spinal nerves arising from the spinal cord.

8. Name the largest cell present in the human body.



9. Why is the use of iodised salt advisable?


The thyroid gland need iodine for the synthesis of the thyroxine hormone. Iodized salt supplies the necessary iodine required by the thyroid gland to produce an adequate amount of thyroxin for our body. The use of iodised salt prevents risk of goiter.

10. Mention the part of the body where gustatory and olfactory receptors are located.


Tongue and Nose.

11. Why endocrine glands release theft secretions into the blood?


Endocrine glands are ductless glands and their products have to act at a distant site.

12. Who transmits nerve impulse across the synapse?



13. How does a touch-me-not plant respond on touching? What is this movement called?


Touch-me-not plant folds its leaflets on touching. This type of movement is called Growth independent movement.

14. Which signal will get disrupted in case of a spinal cord injury?


Reflex actions will be disrupted because reflexes are located in the spinal cord. Therefore, the quick response required to safe guard the body will not take place.

Chapter 6 Control and Coordination Short Questions and Answers

1. How endocrine glands do helps in maintaining feedback control?


The timing and amount of hormones released are regulated by feedback mechanism. For example, glucose level in the blood is maintained constant. The blood glucose levels may be maintained constantly by either of the following feedback mechanism.
(i) High glucose level in the blood induces the pancreatic cells to produce insulin which converts glucose to glycogen.
(ii) Less glucose level in the blood do not induce the pancreatic cells to produce insulin so that less conversion of glucose to glycogen may occur.

2. How does auxin promote phototropism?


Auxin, a plant hormone produced in the shoot tips, promotes cellular elongation. When light is incident on one side of the plant, auxin molecules disperse towards the shaded side of the shoot. The concentrated accumulation of auxin promotes elongation of cells on the shaded side of the shoot. Therefore, the plant shows a phenomenon of bending towards the source of light during its growth. This phenomenon is called phototropism.

3. What are plant hormones? Name the plant hormones responsible for the following:
(a) Growth of stem
(b) Promotion of cell division
(c) Inhibition of growth
(d) Elongation of cells


Plant hormones are chemical substances which help the plant to coordinate growth and development.
(a) Auxins/ Gibberellins
(b) Cytokinins
(c) Abscisic Acid
(d) Auxins/ Gibberellins

4. Give one example of following plants:
(a) Which is
(i) positively phototropic and
(ii) negatively geotropic.
(b) Which is positively hydrotropic as well as positively geotropic?
(c) Which synthesises auxin?


(a) (i) Positively phototrophic: Shoot
(ii) Negatively geotropic: Shoot
(b) Root
(c) Shoot tip

5. Explain giving reasons the bending of the shoot tip of a plant towards light source coming from one side of the plant.


When a plant shoot tip senses light, it triggers the creation of a hormone called auxin in the shoot tip, which is responsive to light.
Auxin diffuses towards the shady side of the stem. It stimulates the growth of cells on the shady side of the plant which causes bending of the plant to the other side. This gives the appearance that the stem of the plant bends in the direction of light.

6. What is geotropism? Draw a labelled diagram of a potted plant showing positive geotropism and negative geotropism.


The movement of plant part in response to gravity is called geotropic movement and the phenomenon involved is called geotropism.

When the tip of the stem grows away from the earth’s gravitational forces, it is known as negative geotropism and when the root tips grow towards gravity, it is known as positive geotropism. In the above figure, stem shows negative geotropism while roots show positive geotropism.

7. Different parts of brain are associated with specific functions. Name the part of human brain which performs the following functions:
(a) Sensation of feeling full
(b) Vomiting
(c) Picking up a pencil
(d) Riding a bicycle


(a) Forebrain
(b) Medulla/ Hind Brain
(c) Cerebellum/ Hind Brain
(d) Cerebellum/ Hind Brain

8. A squirrel is in a scary situation. Its body has to prepare for either fighting or running away. State the immediate changes that take place in its body so that the squirrel is able to either fight or run.


Adrenaline hormone will be secreted in the body as the squirrel is in scary situation. This will result in:
(i) Speeding up of heartbeat
(ii) Rise in blood pressure
(iii) Release of more glucose in the blood.

9. Name the parts of the brain that perform the following functions:
(i) Maintaining the posture and balance of the body.
(ii) Regulating blood pressure.
(iii) Sensation of hunger or feeling full.
(iv) Seeing


(i) Cerebellum
(ii) Hind brain
(iii) Fore brain
(iv) Fore brain

10. Define neuron. Name the parts of neuron where:
(i) Information is acquired.
(ii) Impulse must be converted into chemical signal for onward transmission.


The unit which makes up the nervous system is called neurons.
(i) End of dendrite tip of nerve cell.
(ii) Dendrite → cell body → axon to its ends.

11. Why is chemical communication better than electrical impulses as a means of communication between cells in a multi-cellular organism?


Chemical communication surpasses electrical impulses due to its dependence on hormones, which may spread throughout the body and enable cell communication without direct interaction. Also, this form of communication can be consistently maintained and is easy to regulate.

12. Nervous and hormonal system together perform the function of control and coordination in human beings. Justify this statement with the help of an example.


The hypothalamus plays a crucial function in receiving neural signals from the brain and releasing hormones to govern and coordinate the neurological and hormonal systems in human beings. In cases of iodine shortage, the hypothalamus produces hormones that stimulate the pituitary gland. The pituitary gland then sends stimulating hormones to the thyroid gland, which in turn secretes thyroxine. Thyroxine is responsible for regulating carbohydrate metabolism.

13. Trace the sequence of events which occur when a bright light is focused on your eyes.


When bright light is directed towards our eyes, the photoreceptors produce electrical signals and transmit them to the sensory neurons. They transmit the sensations to the spinal cord, which then conveys the message to the brain. The brain transmits a signal to the muscles of the eyelids, causing them to contract and close the pupil.
Receptor → Sensory neuron → Spinal cord → Brain → Motor neuron → Eye → Contraction of eye muscles

14. What is feedback mechanism of hormonic regulation. Take the example of insulin to explain this phenomenon.


The feedback mechanism of hormonal regulation is responsible for controlling the precise timing and quantity of hormone release. When blood sugar levels increase, the pancreatic cells recognise this and respond by increasing the production of insulin. Insulin production decreases when the blood sugar level decreases.

15. Name the hormones by the following endocrine glands and specify one function of each:
(a) Thyroid
(b) Pituitary
(c) Pancreas


(a) Thyroxine regulates carbohydrate, protein and fat metabolism. It controls metabolism for balance of body growth.
(b) Growth hormone regulates growth and development of body.
(c) Insulin, regulates/decreases blood sugar level.

Chapter 6 Control and Coordination Long Questions and Answers

1. (i) Define reflex action. State its significance.
(ii) How do plants respond to external stimuli?


(i) Reflex action is defined as an unconscious, automatic and involuntary response of effectors, i.e. muscles and glands, to a stimulus, which is monitored through the spinal cord. Significance: It protects us from any sudden stimulus which may harm us.
(ii) Plants have responses to many external stimuli such as light, gravity, touch, chemicals, and more. They react to cues from the environment by using receptors and hormones. Receptors enable plants to perceive environmental stimuli and respond accordingly. They display tropic responses to external stimuli, often by exhibiting positive or negative phototropism. For example, auxin is a phytohormone synthesised in the apical meristem and roots, regulating the direction of plant development.

2. (i) Define reflex arc. Draw a flowchart showing the sequence of events which occur during sneezing.
(ii) List four plant hormones. Write one function of each.


(i) The pathway taken by nerve impulses in a reflex action is called the reflex arc. Sequences of events, which occur during sneezing, are:

  • Nerve endings located in the nasal passage identifies the irritant entered in the nose.
  • Receptors send the information or nerve impulses to the sneezing centre located in the brain stem.
  • Brain stem in return sends the instructions to the lungs or diaphragm for response
  • Diaphragm moves abruptly, chest muscles contract in response to the instructions received.
  • Air blows out from nose and mouth instantly and rapidly
  • Sneezing occurs in response to the irritant

(ii) Auxin: It promotes elongation and division of cell and root formation.
Gibberellins: They help in growth of stem and also induce internodal growth in genetically dwarf varieties of plants.

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