TYPE OF CELLS.
There are three types of cells.
1.Prokayotic.
2.Mesokaryotic.
3.Eukaryotic.
ON THE BASIS OF NUCLEUS CELL ARE OF TWO TYPE_____
1.Prokaryotic (Primitive type of nucleus).
2.Eukaryotic (Advance type of nucleus).
Prokaryotes:- Organisms in which the nuclear material is not bounded by a definite nuclear membrane are called Prokaryotes.
IT INCLUDES ALL THE BACTERIA AND BLUE GREEN ALGAE.
BLUE GREEN ALGAE:- first autotrophs.
-Cyanobacteria.
placed in kingdom :--monera.
Prokaryotes :-Have nucleoid/genephore/bacterial chromosome.
EUKARYOTES:-
Organism in which the nucleus has a definite nuclear membrane are called Eukaryotes.
includes:- Protista ,plantae,fungi,Animalia.
MESOKARYOTES:- nucleus,have nuclear membrane.
DNA have no histone protein.
THE CELLS OF PROKARYOTES AND EUKARYOTES DIFFER FUNDAMENTALLY IN MANY WAYS---
1.Prokaryotes and eukayotes term proposed by DAUGHTERY.
2.MESOKARYOTIC TERM , DODGE.
3. In mesokaryotic cell nucleus have nuclear membrane. But the DNA have no histone protein which are required for chromosome formation.
DINOFLAGELLATES ALGAE ARE THE ONLY KNOWN MESOKARYOTES.
ALGAE ARE THE ONLY ORGANISMS WHICH SHOW ALL THREE TYPES OF CELLS.
Prokaryotes(BGA)
Mesokaryotic(dinoflagellate)
EUKARYOTE(all other algae)
FUNDAMENTAL DIFFERENCE BETWEEN PROKARYOTES/EUKARYOTES .
In prokaryotic cells the nuclear material remain exposed in the cytoplasm .such nucleus are known as nucleoid or genephore.
Chromosome:- In prokaryotes the genetic material consists of double stranded circular DNA it is associated with histone protein this circular DNA represents the prokaryotic nucleus called the nucleoid . on the other hand the Eukaryotic cell have DNA with histone protein in the form of chromatin .
DNA + Histone is equals to chromatin.
Cytoplasmic organelles:-
Prokaryotic cell have no endoplasmic reticulum, Golgi Complex, mitochondria, lysosome or centrioles .
All the member bound cell organelles are absent in prokaryotic cell, so we can say that in prokaryotic cell extracellular compartment are absent.
the only cell organelle that is present in the prokaryotic cell is membrane less 70s ribosome there are dispersed in the cytoplasm of the prokaryotic cells that's why the cytoplasm of prokaryotic cell is granular .
the prokaryotic cell have only one envelope system it means these have only a single membrane that is cell membrane on the other hand Eukaryotic cell have all the cell organelle is and possessed internal membrane system the ribosomes are of 80s type which is bounded to endoplasmic reticulum.
the cell wall of prokaryotes is made up of peptidoglycan which is also called in Murein. Eukaryotic cell is made up of cellulose which is the polymer of glucose .
Respiration and photosynthesis ,:-
In prokaryotic cells respiratory cell organelle mitochondria is absent but enzymes for respiration are closely associated to the plasma membrane or cell membrane. sometime the cell membrane folded towards inner side and form a sum invagination which are called them is Mesosomes. these are analogous to mitochondria.
In prokaryotes the chloroplast is absent but in place of some membrane lamellae are present which possess photosynthetic pigment, these lamellae are known as photosynthetic lalellae chromatophores.
These are analogous to thylakoid of chloroplast of of eukaryote.
FLAGELLA:-
the prokaryotic flagella do not show 9 + 2 arrangement internally while in the Eukaryotic cilia or flagellar have a definite structure consisting of two Central and 9 peripheral fibrils.
cytoplasmic movements :-protoplasmic movement is absent in prokaryotes while it occur in eukaryotes which is called streaming movement or cyclosis.
1.Prokayotic.
2.Mesokaryotic.
3.Eukaryotic.
ON THE BASIS OF NUCLEUS CELL ARE OF TWO TYPE_____
1.Prokaryotic (Primitive type of nucleus).
2.Eukaryotic (Advance type of nucleus).
Prokaryotes:- Organisms in which the nuclear material is not bounded by a definite nuclear membrane are called Prokaryotes.
IT INCLUDES ALL THE BACTERIA AND BLUE GREEN ALGAE.
BLUE GREEN ALGAE:- first autotrophs.
-Cyanobacteria.
Prokaryotes :-Have nucleoid/genephore/bacterial chromosome.
EUKARYOTES:-
Organism in which the nucleus has a definite nuclear membrane are called Eukaryotes.
includes:- Protista ,plantae,fungi,Animalia.
MESOKARYOTES:- nucleus,have nuclear membrane.
DNA have no histone protein.
THE CELLS OF PROKARYOTES AND EUKARYOTES DIFFER FUNDAMENTALLY IN MANY WAYS---
1.Prokaryotes and eukayotes term proposed by DAUGHTERY.
2.MESOKARYOTIC TERM , DODGE.
3. In mesokaryotic cell nucleus have nuclear membrane. But the DNA have no histone protein which are required for chromosome formation.
DINOFLAGELLATES ALGAE ARE THE ONLY KNOWN MESOKARYOTES.
ALGAE ARE THE ONLY ORGANISMS WHICH SHOW ALL THREE TYPES OF CELLS.
Prokaryotes(BGA)
Mesokaryotic(dinoflagellate)
EUKARYOTE(all other algae)
FUNDAMENTAL DIFFERENCE BETWEEN PROKARYOTES/EUKARYOTES .
In prokaryotic cells the nuclear material remain exposed in the cytoplasm .such nucleus are known as nucleoid or genephore.
Chromosome:- In prokaryotes the genetic material consists of double stranded circular DNA it is associated with histone protein this circular DNA represents the prokaryotic nucleus called the nucleoid . on the other hand the Eukaryotic cell have DNA with histone protein in the form of chromatin .
DNA + Histone is equals to chromatin.
Cytoplasmic organelles:-
Prokaryotic cell have no endoplasmic reticulum, Golgi Complex, mitochondria, lysosome or centrioles .
All the member bound cell organelles are absent in prokaryotic cell, so we can say that in prokaryotic cell extracellular compartment are absent.
the only cell organelle that is present in the prokaryotic cell is membrane less 70s ribosome there are dispersed in the cytoplasm of the prokaryotic cells that's why the cytoplasm of prokaryotic cell is granular .
the prokaryotic cell have only one envelope system it means these have only a single membrane that is cell membrane on the other hand Eukaryotic cell have all the cell organelle is and possessed internal membrane system the ribosomes are of 80s type which is bounded to endoplasmic reticulum.
the cell wall of prokaryotes is made up of peptidoglycan which is also called in Murein. Eukaryotic cell is made up of cellulose which is the polymer of glucose .
Respiration and photosynthesis ,:-
In prokaryotic cells respiratory cell organelle mitochondria is absent but enzymes for respiration are closely associated to the plasma membrane or cell membrane. sometime the cell membrane folded towards inner side and form a sum invagination which are called them is Mesosomes. these are analogous to mitochondria.
In prokaryotes the chloroplast is absent but in place of some membrane lamellae are present which possess photosynthetic pigment, these lamellae are known as photosynthetic lalellae chromatophores.
These are analogous to thylakoid of chloroplast of of eukaryote.
FLAGELLA:-
the prokaryotic flagella do not show 9 + 2 arrangement internally while in the Eukaryotic cilia or flagellar have a definite structure consisting of two Central and 9 peripheral fibrils.
cytoplasmic movements :-protoplasmic movement is absent in prokaryotes while it occur in eukaryotes which is called streaming movement or cyclosis.
Comments