question_answer 71)

  Fill in the blanks (a) Cork cells possesses ......... on their walls that makes it impervious to gases and water. (b) ........ have tubular cells with perforated walls and are living in nature. (c) Bone possesses a hard matrix composed of......... and ......... .

Answer:

  (a) suberin                          (b) Sieve tubes of phloem                           (c) proteins and minerals