Question

(a) Why do the tips of roots and stems stop growing if you cut them at the tip ?
(b) Why do we call the blood as connective tissue ?

CBSE Class IX Science LA (5 Marks)

Answer 1

23.    (a) The growth of plants occurs only in certain specific regions. This is because the dividing cells are present in these regions. These cells are called as meristematic cells. The tip of stems and roots contain these meristematic cells. These cells divide and increase the length of the stem and root. If we cut the tip of stems and root, means we remove the meristematic cell of the tips, hence the tips will stop growing.

(b) The cells of connective tissue are loosely spaced and embedded in intercellular matrix. The matrix may be jelly-like fluid, dense or rigid. Since, blood has a fluid matrix called plasma that contains red blood cells (RBCs), white blood cells (WBCs) and platelets. Blood also transports gases, harmones, digested food, etc. from one part of the body to another.