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.
The two main organs of CNS are brain and spinal cord.
Spinal cord plays a major role in sending command to muscles to act without involving thinking process. This phenomenon is called reflex action.
Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.
(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 the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?
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……………
State the structural and the functional unit of the nervous system. Draw its neat labelled diagram and write two functions.
State the functions of any three of the structural and functional unit of nervous system.
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.
Why is the folding up of the leaves of a sensitive plant on touching with a finger not a tropism ?
(a) What substances are made by endocrine glands ?
(b) What is the function of receptors and effectors in our body ?
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 ?
Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?
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
(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) ?
What is the name of in-built ‘arrangement’ in our body which controls the timing and amount of hormones released by various endocrine glands in the body ?
(a) How does chemical coordination take place in human beings ?
(b) Why is the use of iodised salt advisable ?
What is the function of insulin hormone ? What type of patients are given insulin injections ?
In what ways are puberty and adolescence result of the activity of some glands in the human body ?
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.
(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.
Mention one function for each of these hormones:
(a) Thyroxin (b) Insulin (c) Adrenaline (d) Growth hormone (e) Testosterone.
Smita's father has been advised by a doctor to reduce his sugar intake.
(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.
A young green plant receives sunlight from one direction only. What will happen to its shoots ?