Biology practical = Mitosis root tip squash

Grow garlic over a beaker of water to grow new roots And use a scalpel to cut a few mm off the end

Use mounted needle to split the root at the cut end to show we cut here and so want to observe the other end

Add the tip to a tube with HCl in a water bath and leave for a few mins

To soften and loosen root tissue so cells can be separated

Place the root tip on a watch glass after separating it from HCl and rinse with distilled water

Place tip on a slide and soak up excess water with filter paper

Add 2 drops of methyl blue indicator and use blunt side of mounted needle to squish root tip

To turn the CHROMOSOMES a colour which is visible under the light microscope

So a single layer of cells can be obtained

Use mounted needle to lower coverslip at an angle to remove any air bubbles

Counting the proportion of cells down a field of view are in mitosis

Number of cells in mitosis —————————————— Total number of cells in field of view X100

Calculate the mitotic index for a large number of field of views and find the average value