4) Oxides of nitrogen
     (a)  1, 2 and 3
     (b)  1, 2 and 4
     (c)  1, 3 and 4
     (d)  2, 3 and 4
Ans: (c)
175. Which of the following vitamins is considered to be a hormone? [IAS 1994]
     (a) A
     (b) B
     (c) C
     (d) D
Ans: (d)
176. Match the following:
     A. Tetanus               1. BCG
     B. Tuberculosis          2. ATS
     C. Malaria               3. Ascorbic acid
     D. Scurvy                4. Chloroquin
          A         B         C         D
     (a)  1         2         3         4
     (b)  1         2         4         3
     (c)  2         1         4         3
     (d)  2         1         3         4
Ans: (c)
177. Which of the following pairs belongs to the category of cold-blooded animals?
     (a) Birds and monkeys
     (b) Snakes and birds
     (c) Frogs and snakes
     (d) Rats and lizards
Ans: (c)
178. Athletes normally have larger sized hearts because: [NDA 1995]
     (a) their blood is thicker and requires more heart muscle to circulate it
     (b) greater blood pressure developed during workout requires thicker heart walls
     (c) their cardiac output is regulated by change of cardiac rate during workout
     (d) their cardiac output is regulated by change of stroke volume during workout
Ans: (c)
179. Biopsy is :
     (a) an examination of body after death to determine the cause of death
     (b) an assessment of life forms in an environment
     (c) a psychological study of life in an artificial environment
     (d) a medical diagnostic technique using Cells and tissues
Ans: (d)