(a) Explain feed back mechanism for regulationof hormonal secretion with the help of one example . (b) State two different types of movement in plant. Mention two points of difference between them.

(a) Explain feed back mechanism for regulationof hormonal secretion wi

1.	(a) Explain feed back mechanism for regulationof hormonal secretion with the help of one example . (b) State two different types of movement in plant. Mention two points of difference between them.
Answer» Solution :(a) The timing and amount of hormones relaased by various glands are controlled by the 'feedback mechanism' which isin-bulit in our body. Example, if the SUGER level in the blood rises too much, it is detected by the CELLS of pancreas which responds by producing and secreting more INSULIN into the blood, and as the blood suger fallsto a cartain level the secretion of insulin in reduced automatically. (b) The plant movements made in response to external stimuli fall into two main categories - (i) tropism and (II) nasties . Tropisms. A growth movementsmade in repsonse to external stimuli in which the dircetion of stimulus determines the direction of response is called tropism . So itis a directional movement. Nasties. The movement of a plant part in response to an external stimuli in the direction of response is not determined by the direction of stimulus is called nastic movement. .