Question

Give reason :

1. Meristamatic caells have a promoinent nucleus and dense cytoplasm but they lack vacuole.

2. Intercellular spaces are absent in sclerenchyma tissues.

3. We get a crunchy and granular feeling when we chew pear fruit.

4. Branches of a tree move and bend freely in high wind.

5. It is difficult to pull of husk of coconut

Answer 1

1)Meristematic tissues have the ability to regenerate and grow.The meristematic cell can divide themselves. So they do not need vacuole but require nucleus and thus lack vacuoles.

2)Intercellular spaces are absent in a schlerenchymatous tissue because it contain dead cells and it's main function is to provide strength to the plant if there would have been spaces it could provide only flexibility not strength.

3) It happens due to tissues present in pear called sclerenchyma tissue.The sclerenchyma cells are of two types fibres and sclereids.The sclereids give a crunchy feeling to the pear fruit.

4)They can twist effortlessly in light of the nearness of a basic changeless tissue called collenchyma. One of the elements of the collenchyma is to bolster simple bowing. Accordingly, trees move openly in high wind speed.

5)The husk of a cocunut tree is hard to pull out because ,it is made up of scelerenchyma tissues which is ade of dead cells.Sclerenchyma gives rigidity and stiffness to the plant and also due to the presence of lignin on the walls of the cells we find it tough to pull the husk out.