Q- Give reasons for:
(a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole.
(b) Intercellular spaces are absent in sclerenchymatous tissues.
(c) We get a crunchy and granular feeling, when we chew pear fruit.
(d) Branches of a tree move and bend freely in high wind velocity.
(e) It is difficult to pull out the husk of coconut tree.
Answer- (a) Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole because the meristematic tissues do not need to store any food material or sap but instead of it they are metabolically highly active.
(b) Intercellular spaces are absent in sclerenchymatous tissues because sclerenchymatous tissues are lignified cells.
(c) We get a crunchy and granular feeling, when we chew pear fruit because of it pulp as the pulp of pear fruit contain stone cells or sclereids that makes it not too hard but crunchy in nature.
(d) Branches of a tree move and bend freely in high wind velocity because plants have collenchymal tissues that make it easy for them to bent in high velocity wing. This is also helpful for plants to prevent them from uprooted from soil by high velocity wind.
(e) It is difficult to pull out the husk of coconut tree because husk of the coconut is formed or is consisted of closely formed sclenchymal fibres. So that makes it too hard to pull husk of coconut.