Question

Name types of simple tissues. Mention their functions

Answer 1

Answer:

There are four basic tissue types defined by their morphology and function: epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

Epithelial tissue creates protective boundaries and is involved in the diffusion of ions and molecules.

Connective tissue underlies and supports other tissue types.

Answer 2

Answer:

Parenchyma is the most common simple tissue of the plants with relatively little specialisation. It is composed of cells which are usually isodiametric in shape with intercellular spaces. The cells have active protoplast.

It is also a simple tissue consisting of one type of elements. The cells are somewhat elongate, occurring along the long axis of the body.

The shape of the cells is variable, the short ones being more or less like parenchyma and the longer ones re­sembling the fibrs, which may have, tapering ends often overlapped and inter­locked like fibres. They are usually poly­gonal in cross-section.

Sclerenchyma is another simple tissue nicely adapted for mechanical function. The component cells are usually ‘prosenchymatous’, a term once used to designate the cells much longer than breadth.

The walls are considerably thickened, often heavily lignified with simple pits. The presence of hard elastic secondary wall with low water-content distinguishes sclerenchyma from collenchyma possessing plastic primary walls with high percentage of water.

The shape and size of the cells constituting this tissue are variable. They may be broadly placed into two groups: very much elongate cells, called sclerenchyma fibres, and short cells, isodiametric or irregular in shape, known as sclereids or sclerotic cells.

Though these are the two forms, intermediate types are not uncommon. Moreover, both the forms may remain intermixed in the same strand to carry on the same function.