Cell Division
,Onion root tip cell in metaphase (400x magnification)
1. Cut off two root tips and place them in a small amount of acetic alcohol for
ten minutes 2. Wash the root tips in icy water and leave it in for 5 minutes.
, Then dry it on filter paper 3. Put the root tips in preheated 1M HCI for five
minute 4. Wash the root tips in iced water again and
leave them for five minutes then dry it on filter paper
5. Put the 2 root tips to a microscope slide. Cut each root tip from the growing tip 6.
Break open the root tips with a mounted needle and add one drop of acetic orcein stain. 7.
Cover with a cover slip and bolt firmly with layers of filter paper and press gently to spread the
root tips. 8.
View it under a microscope (X400) and look for cells with chromosomes.
There are four stages of mitosis: prophase, metaphase, anaphase, and telophase.
Prophase
The chromosomes become visible, and the nucleolus becomes less prominent, so the nuclear
membrane breaks down.
Metaphase
Chromosomes are arranged on the equator of the cell. Spindle fibres are attached to the
centromeres. Centromeres are located on the opposite ends of the cell.
Anaphase
Centromere of each pair of chromatids splits and motor proteins walk along the spindle fibres
pulling the chromatids to the opposite poles.
Telophase
The separated chromatids reach the poles and a new nuclear membrane form. The cell now
contains two identical nuclei.
,Onion root tip cell in metaphase (400x magnification)
1. Cut off two root tips and place them in a small amount of acetic alcohol for
ten minutes 2. Wash the root tips in icy water and leave it in for 5 minutes.
, Then dry it on filter paper 3. Put the root tips in preheated 1M HCI for five
minute 4. Wash the root tips in iced water again and
leave them for five minutes then dry it on filter paper
5. Put the 2 root tips to a microscope slide. Cut each root tip from the growing tip 6.
Break open the root tips with a mounted needle and add one drop of acetic orcein stain. 7.
Cover with a cover slip and bolt firmly with layers of filter paper and press gently to spread the
root tips. 8.
View it under a microscope (X400) and look for cells with chromosomes.
There are four stages of mitosis: prophase, metaphase, anaphase, and telophase.
Prophase
The chromosomes become visible, and the nucleolus becomes less prominent, so the nuclear
membrane breaks down.
Metaphase
Chromosomes are arranged on the equator of the cell. Spindle fibres are attached to the
centromeres. Centromeres are located on the opposite ends of the cell.
Anaphase
Centromere of each pair of chromatids splits and motor proteins walk along the spindle fibres
pulling the chromatids to the opposite poles.
Telophase
The separated chromatids reach the poles and a new nuclear membrane form. The cell now
contains two identical nuclei.
