(a) How does control and coordination take place in plants ? How does it differ from that in animals ?
(b) Name five stimuli which act on plants. Name the type of tropism produced by each one of these stimuli.
(c) Define hydrotropism. Give one example of hydrotropism. State whether this example is of positive hydrotropism or negative hydrotropism. Illustrate your answer with the help of labelled diagram.
(a) The plants do not have a nervous system but they can sense things in the presence of stimuli such as light, touch, water etc. and respond to them by the action of hormones. Thus, the plants coordinate their behavior against environmental behavior by using organic chemicals called hormones. This is called chemical coordination. The hormones in plants coordinate their behavior by affecting the growth of a part of the plant resulting in the movement of that plant part in response to a stimulus. The control and coordination in animals takes place by both nervous system and hormones.
(b)
(i) Light – Phototropism.
(ii) Gravity – Geotropism.
(iii) Chemical – Chemotropism.
(iv) Water – Hydrotropism.
(v) Touch – Thigmotropism.
(c) The movement of a plant part in response to water is called hydrotropism. Example: The roots of a plant always go towards water, this is positive hydrotropism.
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
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.
Why is the folding up of the leaves of a sensitive plant on touching with a finger not a tropism ?
Fill in the following blanks with suitable words :
(a) The two examples of effectors are…………. and………………
(b) Our…………. system allows Us to react to our surroundings. Information from receptors passes
along…………. neurons to our brain. Our brain sends impulses along………… neurons to our muscles.
(c) A neuron which carries an impulse to the brain is called a……………….
(d) The neuron which carries a message for action to a muscle or gland is known as a……………….
(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.
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?
A potted plant is made to lie horizontally on the ground. Which part of the plant will show
(i) positive geotropism?
(ii) negative geotropism?
Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?
Nervous and hormonal system together perform the function of control and coordination in human beings. Justify the statement.
Which part of the brain controls involuntary actions? Write the function of any two regions of it.
Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).
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
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.
Smita's father has been advised by a doctor to reduce his sugar intake.
(a) How is brain protected from injury and shock?
(b) Name two main parts of hind brain and state the functions of each.
What is chemotropism? Give one example. Name any two plant hormones and mention their functions.
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?
Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.
a) What are the short fibres of a neuron known as ?
What is the long fibre of a neuron known as ?
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) The human brain can be broadly divided into three regions. Name these three regions.
(b) What is cranium ? What is its function ?
Compare the nervous system and endocrine system (hormonal system) for control and coordination in humans.
(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.
(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 ?
What is synapse ? In a neuron cell how is an electrical impulse created and what is the role of synapse in this context ?
Name any three endocrine glands in human body and briefly write the function of each of them.
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
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.
What is the general name of chemical substances which bring about control and coordination in plants ?
Name one plant hormone that promotes growth and another plant hormone which inhibits growth.
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 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
Name the plant hormones which are responsible for the following effects :
(a) falling of leaves
(b) opening of stomata
(c) bending of stem towards light (d) closing of stomata