Question

identify the given two slides A and B as a parenchyma or sclerenchyma can be identified by which charactersics​

Answer 1

Answer:

AIM

To identify parenchyma and sclerenchyma tissues in plants, from prepared slides and to draw their labelled diagrams.

MATERIALS REQUIRED

Prepared slides of parenchyma, collenchyma and sclerenchyma, compound microscope.

You can also Download tissues class 9 notes PDF to help you to revise complete Syllabus and score more marks in your examinations.

THEORY

A group of cells that are similar in structure and work together to achieve a particular function forms a tissue. The main types of plant tissues include-

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PROCEDURE

Observe the prepared slides of all the plant tissues one by one.

First focus the slide at low power and then observe it at high power.

Study the characters and draw the diagrams in your notebook.

OBSERVATIONS

IDENTIFYING FEATURES

I. Parenchyma

Cells of Parenchyma tissue are isodiametric.

Intercellular spaces are present in between the cells.

Parenchymatous cells possess large central vacuole and peripheral cytoplasm with a nucleus.

These are generally present in the soft parts of plants like leaves, roots, flowers, etc.

The important functions of parenchymatous cells are storage, photosynthesis, etc.

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II. CoIIenchyma

Collenchymatous cells are somewhat oval to elongated.

Each cell possesses large central vacuole and peripheral cytoplasm with prominent nucleus.

Thickenings are present at corners of cells. Thickening comprise of cellulose and pectin.

Intercellular spaces are absent.

Collenchymatous cells are commonly present below the epidermis in petiole, leaves and stems. Its

main function is to provide mechanical strength.

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III. Sclerenchyma

Cells of sclerenchyma tissue are dead with highly thickened walls.

Thickenings consist of lignin.

There are two types of sclerenchyma cells:

fibres which are elongated cells with tapering ends and

sclereids (also called stone cells), which are roughly isodiametric cells with narrow cavities.

Sclerenchymatous cells have pits which act as connections with adjacent cells.

The main function of sclerenchyma is to provide support and mechanical strength to the plant.

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PRECAUTIONS

Handle the microscope carefully.

Always focus the slide first at low power (10 x) and then at high power (40x