Answer briefly :
(a) How do you perceive the colour of an object ?
(b) Which part of our body helps us in maintaining the body balance ?
(c) How does the eye regulate the amount of light that falls on the retina.

Answer briefly: (a) Why are villi present in the intestine and not in the stomach? (b) How does pepsinogen change into its active form? (c) What are the basic layers of the wall of alimentary canal? (d) How does bile help in the digestion of fats?

(a) Write the Haworth structure of maltose. (b) What is peptide Linkages? How many peptide bonds are present in a tetra-peptide? (c) Name the hormone which regulates blood sugar level in the body.

Analyse the observation table which shows variation of image distance [v] with object distance [u] in the case of a convex lens. Answer the questions that follow without doing any calculations. {:("Sl.No","Object distance","Image distance"),(,"u [cm]","v [cm]"),(1,-90,+18),(2,-60,+20),(3,-30,+30),(4,-20,+60),(5,-18,+90),(6,-10,+100):} (a) What is the focal length of the convex lens ? Given reasons to support your answer. (b) Write the Sl.No of the observation which is not correct. How did you arrive at this conciusion ? (c ) Use an appropriate scale to draw the ray diagram for the observation at Sl. No 4 and find the approximate value of magnification.

Answer the following : (a)Explain how different techniques help cancer detection and diagnosis. (b)How doe smoking cuase oxygen deficiency in the body?