what is cell???
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→ Cells are the structural and functional unit of life.
* All living organisms are made up of cell. That's why cell is known as structural unit of life.
* A single cell can perform all life functions with the help of it's components. Therefore it is known as functional unit of life.
→ Robert Hooke first discovered the cell in 1665.
* He prepared a thin slice of cork and observed it under self made microscope. He saw some box like structures which he named as cell.
→ Anton Von Leeuwenhoek first saw the living cell and also first describe the living cell.
→ Cells can replicate independently.
→ It contain hereditary information due to presence of nucleus or nucleoid.
→ All organisms are made up of cells. Organisms with single cells are known as unicellular organisms. And organisms with multiple cells are known as multicellular organisms.
→ Cells size ranges from 1 - 100 μm.
→ Mycoplasmas, is the shortest cell (0.3 μm) and ostrich egg and nerve cells are the largest cell.
→ Cells are in different shapes. Their shape vary with their function. They may be cuboid, thread like, disc like etc.
→ Cells are of two types namely; Eukaryotic an Prokayotic cells.
a) Eukaryotic cells :-
* These are generally large in size.
* Nuclear region is well defined and surrounded by a nuclear membrane.
* These are multicellular.
* Single chromosome are present.
* Member bound cell organelles are present such as mitochondria, endoplasmic reticulum, golgi appartus etc.
* DNA is linear.
* Cell divides by binary fission and budding.
* Ex :- Human beings, plants etc.
b) Prokayotic cells :-
* These are smaller in size.
* Nuclear region is not well defined and not surrounded by a nuclear membrane.
* These are unicellular.
* More than one chromosomes are present in it.
* Membrane bound cell organelles are absent such as mitochondria, endoplasmic reticulum, golgi appartus etc.
* DNA is circular.
* Cell divides by mitosis and meiosis.
* Ex :- Bacteria, blue-green algae etc.
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@Sakshimaan that is what a perfect answer is!
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The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life. Cells are often called the "building blocks of life". The study of cells is called cell biology.
This article is about the term in biology. For other uses, see Cell.
Quick facts: MeSH, TH …
Cell
Onion (Allium cepa) root cells in different phases of the cell cycle (drawn by E. B. Wilson, 1900)

A eukaryotic cell (left) and prokaryotic cell (right)
IdentifiersMeSHD002477THH1.00.01.0.00001FMA68646Anatomical terminology
[edit on Wikidata]
Close
Structure of an animal cell
Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Organisms can be classified as unicellular (consisting of a single cell; including bacteria) or multicellular (including plants and animals). While the number of cells in plants and animals varies from species to species, humans contain more than 10 trillion (1013) cells. Most plant and animal cells are visible only under a microscope, with dimensions between 1 and 100 micrometres.
Cells were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth at least 3.5 billion years ago.
Overview
Cells are of two types: eukaryotic, which contain a nucleus, and prokaryotic, which do not. Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular.
Prokaryotic cells
Main article: Prokaryote
Structure of a typical prokaryotic cell
Prokaryotes include bacteria and archaea, two of the three domains of life. Prokaryotic cells were the first form of life on Earth, characterised by having vital biological processes including cell signaling. They are simpler and smaller than eukaryotic cells, and lack membrane-bound organelles such as a nucleus. The DNA of a prokaryotic cell consists of a single chromosome that is in direct contact with the cytoplasm. The nuclear region in the cytoplasm is called the nucleoid. Most prokaryotes are the smallest of all organisms ranging from 0.5 to 2.0 µm in diameter.
This article is about the term in biology. For other uses, see Cell.
Quick facts: MeSH, TH …
Cell
Onion (Allium cepa) root cells in different phases of the cell cycle (drawn by E. B. Wilson, 1900)

A eukaryotic cell (left) and prokaryotic cell (right)
IdentifiersMeSHD002477THH1.00.01.0.00001FMA68646Anatomical terminology
[edit on Wikidata]
Close
Structure of an animal cell
Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Organisms can be classified as unicellular (consisting of a single cell; including bacteria) or multicellular (including plants and animals). While the number of cells in plants and animals varies from species to species, humans contain more than 10 trillion (1013) cells. Most plant and animal cells are visible only under a microscope, with dimensions between 1 and 100 micrometres.
Cells were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth at least 3.5 billion years ago.
Overview
Cells are of two types: eukaryotic, which contain a nucleus, and prokaryotic, which do not. Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular.
Prokaryotic cells
Main article: Prokaryote
Structure of a typical prokaryotic cell
Prokaryotes include bacteria and archaea, two of the three domains of life. Prokaryotic cells were the first form of life on Earth, characterised by having vital biological processes including cell signaling. They are simpler and smaller than eukaryotic cells, and lack membrane-bound organelles such as a nucleus. The DNA of a prokaryotic cell consists of a single chromosome that is in direct contact with the cytoplasm. The nuclear region in the cytoplasm is called the nucleoid. Most prokaryotes are the smallest of all organisms ranging from 0.5 to 2.0 µm in diameter.
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