Biology

Control and Coordination

Question:

(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?

Answer:

(a) The two main constituents of the Central Nervous System in human beings are the brain and the spinal cord.
(b) A living being does not live in isolation. It has to constantly interact with its external environment and has to respond properly for its survival. For example; when a hungry lion spots a deer, the lion has to quickly make a move so that it can have its food. On the other hand, the deer needs to quickly make a move to run for its life. The responses which a living being makes in relation to external stimuli are controlled and coordinated by a system; especially in complex animals. So, control and coordination . is essential in maintaining a state of stability and a steady state between the internal conditions of an organism and the external environment.

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Control and Coordination

Q 1.

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

Q 2.

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

Q 3.

Define reflex action with suitable examples.

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.

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 6.

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 7.

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

Q 8.

What is the autonomic nervous system?

Q 9.

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

Q 10.

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

Q 11.

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

Q 12.

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

Q 13.

A young green plant receives sunlight from one direction only. What will happen to its shoots ?

Q 14.

Name the plant part :
(a) which bends in the direction of gravity but away from light
(b) which bends towards light but away from the force of gravity

Q 15.

(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 16.

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

Q 17.

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

Q 18.

Write the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?

Q 19.

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

Q 20.

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 21.

Write name of three hormones secreted by the pituitary gland.

Q 22.

What are hormones?

Q 23.

(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 24.

Name the most important part of the human brain.

Q 25.

Name two parts of the body which contain receptors of chemical stimuli.

Q 26.

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

Q 27.

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 28.

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

Q 29.

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 ?

Q 30.

(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 31.

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 32.

Name any two types of tropism.

Q 33.

What is a phytohormone? Name any two phytohormones.

Q 34.

What is hydrotropism?

Q 35.

(a) Draw the structure of neuron and label cell body and axon.
(b) Name the part of neuron:
(i) where information is acquired
(ii) through which information travels as an electrical impulse.

Q 36.

(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 37.

Which part of the brain controls involuntary actions? Write the function of  any two regions of it.

Q 38.

How is the spinal cord protected in the human body?

Q 39.

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

Q 40.

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

Q 41.

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

Q 42.

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

Q 43.

What is a tendril ? Name the two types of tendrils. What does a tendril do in response to the touch of a support ? What is this phenomenon known as ?

Q 44.

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

Q 45.

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 46.

(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 47.

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

Q 48.

In what ways are puberty and adolescence result of the activity of some glands in the human body ?

Q 49.

(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 ?

Q 50.

Write the functions of any one part of the hind – brain.