162. Rigidity of cell wall is due to:
     (a) chitin
     (b) lignin
     (c) suberin
     (d) pectin
Ans: (b)
163. In which of the following would you observe high mitochondrial activity? [Asstt Grade 1995]
          1) Germinating seeds
          2) Falling leaves
          3) Ripe fruit
          4) Meristematic tissue
     (a) 1 and 2
     (b) 2 and 4
     (c) 3 and 4
     (d) 1 and 4
Ans: (d)
164. Match the following: [IES 1994]
     Cell organelles            Physiological phenomena
     A. Mitochondria            1. Photosynthesis
     B. Chloroplast             2. Transpiration
     C. Stomata                 3. Respiration
     D. Cell wall.              4. Osmosis
          A           B         C        D
     (a)  1           3         4        2
     (b)  3           1         2        4
     (c)  1           3         2        4
     (d)  3           1         4        2
Ans: (b)
165. Cell theory was propounded by: [BSF Exam 1990]
     (a) R. Virchow
     (b) Robert Hooke
     (c) Schleiden and Schwann
     (d) William Harvey
Ans: (c)
166. Cholera bacillus was discovered by: [CDS 1993]
     (a) Louis Pasteur
     (b) Ronald Ross
     (c) Robert Koch
     (d) Joseph Lister
Ans: (c)
167. Gene was first isolated by: [IRS 1989]
     (a) C. V. Raman
                                                            600