Skip to main content

Cell | What is cell | Cell theory

 Definition Of cell

A cell is a structural and functional unit of life, which carries all activities of life.

Cells are the main building blocks of complex multicellular organisms.

Different cells perform different functions, an organism is the combined sum of activities and interactions of many kinds of cells and of different components of the cell. Modern cell theory is 

Cell Theory Features;

All organisms comprise one or more cells.

All cells arise from preexisting cells.

A cell is a structural and functional unit for all organisms.

What are Types of cells

There are two types of cells are in nature. which are

Prokaryotic cells

Eukaryotic cells 

Prokaryotic cells

Typical Prokaryotes (Greek : pro – before; karyon nucleus)  don't have defined nucleus and contain relatively simple structure.They include the bacteria and cyanobacteria. Most detailed studied prokaryotic cell is Escherichia coli. Organisms containing prokaryotic cells called prokaryotes.


Characteristics of prokaryotic cells

It is small in size and has a minimum of internal organization.

Membrane bound organelles are not present in prokaryotic cells and have small size ribosomes 70S.

 Mitosis or meiosis are not present so the cell is divided by binary fission.

The genetic material of prokaryotic cells is without any nuclear membrane covering and directly suspended in cytoplasm.

Eukaryotic cells 

2. Eukaryotes (Greek : eu – true; karyon 

nucleus) contain a well defined nucleus and are complex in their structure and function.

The higher organisms (animals and plants) including humans are composed of eukaryotic cells.

Organisms containing eukaryotic cells called eukaryotes.

 Characteristics of eukaryotic cells.

Eukaryotic Cells are larger in size and have large ribosomes 80S.

Eukaryotes have a nucleus so nuclear materials ( chromosomes or DNA) are enclosed in a double nuclear membrane.

Mitosis and meiosis both are present in eukaryotes.



Comments

Popular posts from this blog

What is Chromatography and its types

The word ‘chromatography’ is derived from Greek word ‘Chromo’ meaning colour and ‘graphy’ meaning to measure; initially it was used to separate coloured compounds from the mixture.   In another words It is an analytical technique used for the separation of closely related compounds from a mixture. These compounds are proteins, peptides, lipids ,amino acids, carbohydrates, vitamins and drugs. Chromatography was discovered by Russian Botanist Tswest in 1903. He used it for separation of plant pigments for the first time. The early methods used for the separation and purification of compounds from mixtures were labourious, and s  s low.  With passage of time and advancement in the separation techniques over years, the chromatographic technique has become to be known as used for the separation of different compounds from mixture and for their identification. Principle of Chromatography Chromatography is usually  consists of two phases first a mobile phase and secondary i...

What are Types of Chromatography , Paper chromatography

Types of chromatography This technique is mostly used for the separation of amino acids, sugars, sugars derivatives and also for the separation of chemicals by this type of chromatography.  Stationary phase in paper chromatography is Whatman No. 1 or Whatman No. 3 filter papers while Mobile phase is the mixture of water, organic solvents and of various additives. In paper chromatography mixture of compounds to be separate is allowed to rise up and apply on the upward position (called ascending chromatography) at end of filter paper  (usually 2 cm above the paper) by a capillary action or move down by a capillary action on the paper (called descending chromatography). Solution of mixture to be separated applied on filter paper and migration of molecules present in solution occur and after some time paper is dried and dipped in solvent to visualize spots on paper with specific coloring reagents.  Since the speed of migrating molecules is depends on their relative solubility...

Difference between RNA and DNA

Easy and short Difference between RNA and DNA is Here   RNA (Ribonucleic Acid) • RNA is a single stranded structure. It is Present mainly in cytoplasm but some in the nucleus. RNA Contains purines (Adenine and Guanine) And Pyrimidines (Cytosine and Uracil). It Contains Ribose(Sugar) and phosphoric acid. DNA (Deoxyribonucleic Acid) DNA is a double stranded helical structure. It is Present mainly in the nucleus but some in the cytoplasm. it is Contains purines (Adenine and Guanine). And pyrimidines (Cytosine and Thymine). It Contains DeoxyRibose (Sugar) and phosphoric acid.