Biology

Control and Coordination

Question:

What makes a stem bend towards sunlight?

Answer:

The chemical substance called plant hormone or phytohormone makes a stem bend towards sunlight.

 

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Control and Coordination

Q 1.

Why is the response of a plant to a stimulus not observed immediately?

Q 2.

(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 3.

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

Q 4.

Why is it advised to use iodised salt in our diet ?

Q 5.

Give an example of a plant hormone that promotes its growth. Where it is synthesized ?

Q 6.

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

Q 7.

Name the hormones secreted by thyroid, parathyroid and pancreas.

Q 8.

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

Q 9.

(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 10.

(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 ?

Q 11.

(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 12.

Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?

Q 13.

State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone

Q 14.

(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.

Q 15.

How are involuntary actions and reflex actions different from each other?

Q 16.

What are hormones?

Q 17.

How does control and coordination occur in single-celled animals?

Q 18.

What is a plant hormone ? Name four plant hormones. State one function of each.

Q 19.

a) What are the short fibres of a neuron known as ?
What is the long fibre of a neuron known as ?

Q 20.

Name the most important part of the human brain.

Q 21.

Define reflex action with suitable examples.

Q 22.

Name, the two main organs of our central nervous system. Which one of them plays a major role in sending command to muscles to act without involving thinking process? Name the phenomenon involved.

Q 23.

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

Q 24.

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

Q 25.

Give the scientific terms used to represent the following :
(a) Bending of a shoot towards light.
(b) Growing of roots towards the earth.
(c) Growth of a pollen tube towards ovule.
(d) Bending of roots towards water.
(e) Winding of tendril around a support

Q 26.

Name the three components of a neuron (or nerve cell).

Q 27.

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

Q 28.

(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 ?

Q 29.

What is a neuron?

Q 30.

Differentiate between tropic and nastic movements.

Q 31.

Describe the central nervous system in human beings.

Q 32.

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

Q 33.

What is chemotropism? Give one example. Name any two plant hormones and mention their functions.

Q 34.

Name and explain the function of the hormone secreted by the pituitary gland in humans.

Q 35.

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

Q 36.

What is the general name of chemical substances which bring about control and coordination in plants ?

Q 37.

Name the type of chemical substances that control the growth in plants.

Q 38.

Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).

Q 39.

(a) What does a Mimosa pudica plant do in response to touch ? What is this phenomenon known as ?
(b) What happens to the dandelion flower (z) during daytime, and (ii) at night ? What is this phenomenon known as ?

Q 40.

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

Q 41.

Which gland secretes the growth hormone ?

Q 42.

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 43.

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

Q 44.

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 45.

If sugar is detected in the urine of a person, name the disease he is suffering from.

Q 46.

Which one term in each of the following includes the other three ?
(a) thyroid, ductless gland, thymus, pituitary, ovary
(b) adrenalin, insulin, hormone, thyroxine, estrogen

Q 47.

Compare the nervous system and endocrine system (hormonal system) for control and coordination in humans.

Q 48.

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

Q 49.

Explain the difference between each of the following pairs of terms :
(a) receptor and effector (b) cerebrum and cerebellum

Q 50.

Answer the following:
(a) Name the endocrine gland associated with brain?
(b) Which gland secretes digestive enzymes as well as hormones?
(c) Name the endocrine gland associated with kidneys?
(d) Which endocrine gland is present in males but not in females?