How are involuntary actions and reflex actions different from each other?
All reflex actions are involuntary in nature but all involutary actions are not reflexes as the beating of heart is an involuntary action but is not reflex action.
Reflex actions are very quick but all involutary actions may not be very fast as in heart beating.
A reflex action may involve any muscle or a gland as we withdraw our hand on touching a hot object but all involuntary actions involve only smooth i.e., involuntary or cardiac muscles.
Reflex actions are at the level of spinal cord whereas the involuntary actions generally involve brain too.
Nerves and autonomious nervous system can increase or decrease the rate of involuntary actions but reflex actions can be controlled by great will only and are not usually controllable.
Reflex actions are done to meet emergencies where as an inv.action may or may not be for just meeting an emergency but may be a critical lie process as circulation of blood, swallowing of food, movement of food in food pipe, etc.
State the functions of any three of the structural and functional unit of nervous system.
A young green plant receives sunlight from one direction only. What will happen to its shoots ?
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.
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.
Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).
Fill in the following blanks :
(a) A plant’s response to light is called…………..
(b) A plant’s response to gravity is called…………..
(c) Plant shoot grows upward in response to…………….
(d) Plant roots grow downward in response to…………..
(e) Tendrils wind around a support in response to……………
(f) Plant roots grow towards…….. and in the direction of force of……………
(g) A root of a plant grows downward. This is known as…………..
(h) ……….is the hormone that causes phototropism in plants
(i) The response of leaves to the sunlight is called……………
(a) What does a root do in response to gravity ? What is this phenomenon known as ?
(b) What does a stem (or shoot) do in response to light ? What is this phenomenon known as ?
Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.
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.
(a) What are the various sense organs in our body ?
(b) What is meant by receptors and effectors ? Give two examples of each.
(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.
State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone
Write the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?
Explain the difference between each of the following pairs of terms :
(a) receptor and effector (b) cerebrum and cerebellum
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?
What are meanings? What are their functions? Name the fluid, which is filled in between meanings.
(i) Name the hormones that are released in human males and females when they reach puberty.
(ii) Name a gland associated with brain. Which problem is caused due to the deficiency of the hormone released by this gland ?
State the structural and the functional unit of the nervous system. Draw its neat labelled diagram and write two functions.
(a) How is brain protected from injury and shock?
(b) Name two main parts of hind brain and state the functions of each.
(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.
Which organ secretes a hormone when bloo’d sugar rises in our body? Name the hormone and name one enzyme released by this organ.
(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.
What are 'hormones'? State one function of each of the following hormones:
(i) Thyroxine (ii) Insulin
A potted plant is made to lie horizontally on the ground. Which part of the plant will show
(i) positive geotropism?
(ii) negative geotropism?
Name and explain the function of the hormone secreted by the pituitary gland in humans.
Which one of the following actions on touch is an example of chemical control?
(i) Movement on the touch-sensitive plant.
(ii) Movement in human leg.
