Mitosis Practical Flashcards
1
Q
Describe how to prepare squashes of cells from plant root tips
A
1) Cut a thin slice of root tip (5mm from the end) using a scalpel & mount onto a slide
2) Soak root tip into HCl then rinse
3) Stain for DNA e.g Toluidine Blue
4) Lower coverslip using a mounted needle without trapping air bubbles
5) Squash firmly by pressing down (not sideways)
2
Q
Why are root tips used?
A
Where there are dividing cells / Mitosis occurs
3
Q
Why is a stain used?
A
To distinguish chromosomes / Chromosomes not visible without a stain
4
Q
Why squash the cover slip?
A
- To create a single layer of cells
- So light can pass through to make chromosomes visible
5
Q
Why not push the cover slip sideways?
A
Avoid rolling cells together / breaking chromosomes
6
Q
Why soak roots in acid?
A
- Seperate cells / cell walls
- To allow stain to diffuse into cells
- To allow cells to be more easily squashed
- To stop mitosis
