Biology

Control and Coordination

Question:

(a) What does a stem (or shoot) do in response to gravity ? What is this phenomenon known as ?
(b) What does a root do in response to light ? What is this phenomenon known as ?

Answer:

(a) Stem grows upward against the direction of gravity; negative geotropism.(b) Root bends away from light; negative phototropism

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Control and Coordination

Q 1.

What part does the diet play in helping us to have a healthy thyroid gland ?

Q 2.

(a) Explain how auxins help in bending of plant stem towards light.
(b) State the objective of the experiment for which experimental set-up is shown in the given diagram.

Q 3.

Which of the following is a growth movement and which is not ?
(a) folding up of leaves of sensitive plant on touching with hand.
(b) folding up of petals of dandelion flower when light fades.

Q 4.

(a) Name the two main constituents of the Central Nervous System in human beings.
(b) What is the need for a system of control and coordination in human beings?

Q 5.

(a) What does a plant root do in response to water ? What is this phenomenon known as ?
(b) What happens to the moonflower (i) during daytime, and (ii) at night ? What is this phenomenon known as ?

Q 6.

Name the disease caused by the deficiency of insulin hormone in the body.

Q 7.

Name one gland each :
(a) which acts only as an endocrine gland.
(b) which acts only as an exocrine gland.
(c) which acts both as an endocrine gland as well as an gxocrine gland.

Q 8.

(a) What is spinal cord ? What is its main function ?
(b) Give the functions of medulla.

Q 9.

What are the major parts of the brain? Mention the functions of different parts.

Q 10.

What is the autonomic nervous system?

Q 11.

Define reflex action with suitable examples.

Q 12.

Name the part of the brain which controls posture and balance of the body.

Q 13.

Name any three endocrine glands in human body and briefly write the function of each of them.

Q 14.

What is a reflex action? Describe the steps involved in a reflex action.

Q 15.

Name the five types of tropisms. How are tropic movements helpful to plants ? Explain with an example.

Q 16.

Name the hormones secreted by (a) testes, and (b) ovaries

Q 17.

What does CNS stand for ? Which part of CNS : (a) consists of two cerebral hemispheres, and (b) has spinal nerves attached to it ?

Q 18.

What is the need for a system of control and coordination in an organism?

Q 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?

Q 20.

(a) Which plant hormone is present in greater concentration in the areas of rapid cell division?
(b) Give one example of a plant growth promoter and a plant growth inhibitor.

Q 21.

To which directional stimuli do :
(a) roots respond ?
(b) shoots respond ?

Q 22.

Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.

Q 23.

Which part of the brain maintains posture and balance of the body ?

Q 24.

State one function each of cerebellum and pons.

Q 25.

What are the two main communications systems in an animal’s body ?

Q 26.

Give three examples of reflex actions.

Q 27.

(a) Name the hormones secreted by the following endocrine glands :
(i) Thyroid gland (ii) Parathyroid glands (iii) Pancreas (iv) Adrenal glands
(b) Write the functions of testosterone and oestrogen hormones.

Q 28.

What is the function of insulin hormone ? What type of patients are given insulin injections ?

Q 29.

How does chemical coordination occur in plants?

Q 30.

Name the plant hormones responsible for the following:
(a) Elongation of cells.
(b) Growth of stem.
(c) Promotion of cell division.
(d) Falling of senescent leaves.

Q 31.

Name any two types of tropism.

Q 32.

List the functions of testosterone and estrogen.

Q 33.

Write name of three hormones secreted by the pituitary gland.

Q 34.

What makes a stem bend towards sunlight?

Q 35.

What is synapse ? In a neuron cell how is an electrical impulse created and what is the role of synapse in this context ?

Q 36.

How is the spinal cord protected in the human body?

Q 37.

Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?

Q 38.

What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?

Q 39.

If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is this type of action known as ?

Q 40.

Name the most important part of the human brain.

Q 41.

What are the scientific names for the following receptors in animals ?
(a) receptors for light
(b) receptors for heat
(c) receptors for sound
(d) receptors for smell
(e) receptors for taste

Q 42.

Why are some patients of diabetes treated by giving injections of insulin ?

Q 43.

Why do you need iodine in your diet ?

Q 44.

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.

Q 45.

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.

Q 46.

(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.

Q 47.

Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the given figure.
ncert-exemplar-class-10-science-chapter-5-control-and-coordination-1

Q 48.

What will happen if intake of iodine in our diet is low?

Q 49.

Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?

Q 50.

What is a neuron?