July 21, 2021

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To identify Parenchyma and Sclerenchyma tissues in plants from prepared slides

To identify Parenchyma and Sclerenchyma tissues in plants from prepared slides?

To identify Parenchyma and Sclerenchyma tissues in plants from prepared slides. Draw their labeled diagrams. – Class 9th Science Lab Work


Experiment -6

Aim

To study of parenchyma and Sclerenchyma tissues in plants from prepared slides.

Theory

Flowering plants are structurally complex as they are made up of different parts like roots, stem, leaves, flowers, fruits, etc. Each part is in turn an assembly of different types of tissues. Each tissue type has specific structure and performs a particular function. Plant tissues are broadly classified into meristematic and permanent tissues. Permanent tissues may be simple, permanent tissues like parenchyma, collenchyma and sclerenchyma. Complex permanent tissues are xylem and phloem. The structural features of tissues like wall characteristics, cell size, lumen size, and cytoplasmic contents are different in different tissues.

Materials Required
Tender stem of a herb, safranin stain solution, dilute glycerine, chart of transverse section of stem, compound microscope, razor blade, slide, cover slip, brush, petridish, and a piece of blotting paper.

NOTE : The student doesn’t need to write the procedure because they will be given the prepared slide however we are giving it for reference. The students only need to write the observation skipping the procedure part. 

Procedure

Step 1: A tender stem of any of the herb will cut into bits of about 3 cm length and placed in water.
Step 2: A piece is hold between the thumb and forefinger in your left hand.
Step 3: A wet blade across the stem is passed in quick motion so as to get a thin, unbroken, circular cross section of the material.

Step 4: The process will repeat to get about fifteen transverse sections of the material.
Step 5: The sections is transferred to a petridish containing water. A thin, transparent section is selected and with a brush transfer it to a drop of water taken on a slide. Three drops of dilute safranin stain solution is added to the section and leave it for about five minutes.
Step 6: The excess stain is blotted. Three drops of dilute glycerine is added on the stained section. A cover slip is placed on it. It is then focused under the low power of microscope and observe the section.
Step 7: The section is focused under high power and observed again. The observations are recorded.

 

Observation

S. No. Feature Parenchyma Sclerenchyma
1 Shape of cell        oval or spherical         elongated and polygonal
2 Arrangement of cells loose compact
3 Inter cellular spaces present absent
4 Lumen absent present
5 Nucleus present absent
6 Cell wall present present
8 Staining of wall deeply stained midly stained
7 Cytoplasm present absent

Results and Discussion

Parenchyma tissue is the most abundant type of tissue in plants. It forms the major bulk of stem, roots, leaves, fruits and seeds. The tissue composed of living cells, with various shapes, sizes and functions. The cells provide mechanical support to the plant body. The parenchyma also acts as a storage tissue for food, air and water. Cells of Sclerenchyma tissue are highly lignified with very thick cell walls and obliterated lumen.

Precautions

1. For sectioning, select soft, tender herbaceous stem only. Avoid stems that are hard and woody.
2. Take care not to injure your finger while sectioning.
3. Always keep the plant materials and sections in water.
4. Use dilute safranin stain solution.
5. The trachea and tracheids of xylem tissue appear to be very much similar to Sclerenchyma and may be erroneously identified as Sclerenchyma tissue.

 


To identify Parenchyma and Sclerenchyma tissues in plants from prepared slides?

CBSE Class 9 Science Practicals Syllabus – List of Experiments

Lab manual/Experiments of CBSE 

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