Question

Give reasons of the following statements -

a). Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuoles .

b). Intercellular spaces are absent in schelerenchymatous tissue .

c). Branches of a tree moveandm bend freely in high wind velocity .

Answer 1

a) Meristematic cells are the continously dividing cells of the plant body i.e., they remain metabolically active and as we know that vacuoles serve the purpose of storage in plant cells. Therefore meristematic cells do not require vacuole.Meristematic cells are highly dividing cells of a plant and they require energy for this purpose ,and energy comes from the glucose they make .because they need energy frequently they do not have much food to store in,so they do not have vacuole and have a prominent and large nucleus .these cells have a protective function ,which is, not to allow any germs to enter in plant so they lack intercellular spaces and have a dence cytoplasm



b) Sclerenchyma tissue are dead simple permanent tissue of the plant. The cells of sclerenchyma are closely packed without intercellular spaces, like tiles in mosaic floor so that, it can provide the strength, rigidity, flexibilty and elasticity to the plant to withstand various strains.also,The main function of sclerenchyma is to provide a rigid n strong support to the plant part.
if there would be any intercellular spaces, it would not b able to provide rigidity.


d) Collenchyma cells are characterised by the deposition of extra cellulose at corners of the cell. In collenchyma intercellular spaces are absent and ceils are elongated. It is a mechanical tissue which provides support and elasticity to the branches of a tree so that, they move and bend freely in high wind velocity.