written by: suhail ahanger · 2020-04-20 · diy microscope is a prerequisite tactivity that has to...

Microscope - Leaf VenationObserve leaf pattern of different types of leaves.

Written By: Suhail Ahanger

Microscope - Leaf Venation 2020-04-19[major]2.4Release:Guide ID: 324 -

This document was generated on 2020-04-19 11:38:32 PM (MST).

© 2020 of 9

INTRODUCTION

A leaf has 2 parts namely the leaf blade and the stalk. The leaf blade consists of the apex, veins,midrib, margin and base. The arrangement of veins in a leaf blade is known as venation. The veinshelp in the transport of food and water.

In this TACtivity, observe a leaf lamina and its different parts (apex, margin, veins, veinlets), usingyour own DIY microscope.

TOOLS:Scissors (1)Paper Cutter (1)Rubber Band (1)Prerequisite TACtivity (DIY Microscope) (1)

PARTS:Leaf (1)

Both Monocot and DicotTape (1)

TransparentTransparent Slide (1)



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— Precautions

Be careful while handling the scissors and any other sharp tool.

— Prerequisite TACtivity

DIY Microscope is a prerequisiteTACtivity that has to be completedbefore commencing this TACtivity.The DIY Microscope is created withtwo glass beads of 4.5mm and2.5mm diameter offering a 40X /100X magnification.

Go to DIY Microscope to completethe TACtivity.



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https://www.tactivity.in/Guide/DIY+Microscope/480

— Step 1 - Preparing the Slide

Carefully remove the transparent layer from both the sides of the slide.

Wipe the slide with tissue paper.

— Step 2 - Preparing Sample A

Select a small, thin and fresh leaf to observe the venation pattern on it.

Leaves have two surfaces - smooth (top) and rough (bottom). The rough surface is placedtouching the slide (indicated with a blue arrow).

Secure the leaf on the slide with clear tape.



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— Step 3 - Viewing Sample A through the Microscope

View the leaf venation using your 4.5 mm bead of DIY Microscope. Ensure that there is a brightlight source behind the slide.

Observe the veins, veinlets, midrib and other parts of the leaf using both beads of the microscope.

Refer to the graphical representation in second picture to compare different parts.

— Play I

Notice the origin of the veins in the midrib. Veins originate from the mid rib at different position.

The apex region observed using the microscope.

The margins, as seen through the microscope.



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— Step 4 - Cutting Sample B

Select a long, thin and fresh leaf and cut a small portion of the following separately:

Apex

Margin

Central portion

— Step 5 - Preparing Sample B

Stick the leaf samples on a slide (with smooth side up) with transparent tape and observe themusing your microscope.



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— Play II

Apex with hairy texture as observed under the microscope.

The origin of veins in the midrib.

The margin with a wavy shape and hair on it.

— Step 6 - Preparing Sample C

Take a blade of grass (or any other monocot leaf) and cut a small portion of its apex.

Also cut a 1 cm section from the middle of the leaf.

Stick the sample onto the slide with a piece of transparent tape. Make sure the leaf is secure fromall sides.



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— Play III

Look for the origin of the venation and midrib (if any).

Notice the margin which has a hairy texture.

Refer to the graphical representation in third picture to compare different parts of the grass blade.

— Troubleshooting

Unclear image -Ensure that the side of the slide with the object mounted is in contact with the microscope.

Move the microscope bead slightly up or down using the straw till you get the focus (sharpimage).

Patterns on the leaf are not clear -Make sure bright light (phone light, torch or bright daylight) is illuminating the slide from behind;do not point towards the Sun.

Choose a thin, small and fresh leaf.



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— Suggested Variations

Try preparing a slide with a dried/yellow leaf and observe the venation pattern.

Thin veins in thick midrib

Thin veins running parallel to each other

Leaf with wavy margin.

For more variations, Go to Microscope - Leaf Venation (Variations) .



© 2020 of 9

https://www.tactivity.in/Guide/Microscope+-+Leaf+Venation+(Variations)/140#s7612

written by: suhail ahanger · 2020-04-20 · diy microscope is a prerequisite tactivity that has to...

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