TYPES OF CELL
Generally cells are
classified into two types. First one is Prokaryotic cell .It has No true
nucleus consisting of no nuclear membrane. Another one is Eukaryotic cell. It
has True nucleus consisting of nuclear membrane.
1. Prokaryotic cell
The unicelluar organisms like Bacteria has
Prokaryotic cells. It has No true nucleus. This type of nucleus is called as
nucleiod. No nuclear membrane is around this nucleiod. These cells were the
first form of life on earth. It is ranging from 0.003 to 2.0 micro meter in
Eg. Eschericia coil
2. Eukaryotic cell
Cells which has true nucleus is called as
eukaryotic cell. It is bigger than prokaryotic cells. It’s organelles bounded
most of the fungi and algae.
Aim: To observe onion peel cells under
Materials Required: Glass slide, cover slip,
onion, iodine solution, knife and microscope.
Take an onion and cut it into
two halves along its length. Take out one of its fleshy leaves. With the help
of a pair of forceps, remove a transparent, thin peel from the inner surface of
the leaf. Take a glass slide and put a drop of water at the centre. Place the
peel on the drop of water. Pour a drop of iodine solution on the peel. Now
place a cover slip over the material. Observe under the microscope.
You will be able to see rectangular
cells of the onion peel, with a nucleus in each of them.
Differences between Prokaryotic
cell Eukaryotic cell
• It’s diameter ranges from 1 to 2 micron
• Absence of membrane bound organelles
• Nucleus consisting of no nuclear membrane
• Absence of nucleoli
• It’s diameter ranges from 10 t0 100 micron
• Presence of membrane bound organelles
• True nucleus consisting of nuclear membrane
• Presence of