(a) The human brain can be broadly divided into three regions. Name these three regions.
(b) What is cranium ? What is its function ?
(a) The 3 regions of human brain are
(i) Forebrain
(ii) Midbrain and
(iii) Hindbrain.
(b) Cranium is a bony box in the skull in which the brain is present. Its function is to protect the brain.
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
A potted plant is made to lie horizontally on the ground. Which part of the plant will show
(i) positive geotropism?
(ii) negative geotropism?
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.
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
(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?
Which part of the brain controls involuntary actions? Write the function of any two regions of it.
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
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).
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……………….
State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone
Nervous and hormonal system together perform the function of control and coordination in human beings. Justify the statement.
Smita's father has been advised by a doctor to reduce his sugar intake.
What is chemotropism? Give one example. Name any two plant hormones and mention their functions.
What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?
(a) What is meant by ‘tropisms’ (or tropic movements) ? Explain with an example.
(b) What are the different types of tropisms ? Define each type of tropism. Write the name of stimulus in each case.
(c) How do tropisms differ from nasties (or nastic movements) ?
Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?
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.
Write the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?
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.
(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.
What are 'hormones'? State one function of each of the following hormones:
(i) Thyroxine (ii) Insulin
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
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.
Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.
Name the plant organs which are :
(a) positively phototropic (b) positively geotropic
(c) negatively geotropic (d) positively hydrotropic
(a) What are the various sense organs in our body ?
(b) What is meant by receptors and effectors ? Give two examples of each.
(a) What substances are made by endocrine glands ?
(b) What is the function of receptors and effectors in our body ?
a) What is the function of our nervous system ?
(b) What are the main organs of the human nervous system ? Draw a labelled diagram to show the main organs of the human nervous system.
(c) How does the human nervous system work ? Explain.
