Previous Topic :Living Cell As A Colony
Living Cell As A Filament
Living cells may also exist as a filament
Example of such living things is a spirogyra.
Spirogyra is a common green filamentous alga.
Characteristics Of Living Cell As A Filament
a] Habitat : Spirogyra is found in slow flowing freshwater streams and ponds as floating green masses near the surface of the water.
I hope we have all experience that when passing along side a stream or pond and you see the pond or stream covered with floating green something,
Where that thing is called spirogyra.
b] Structure : many spirogyra filament are held together by a slimy mucilage. When you put a small sample of spirogyra under the microscope, the filament is seen to be made up of individual cells joined together from end to end.top↑
Living Cell As A Tissue
A unicellular organism consists of one cell only. Organisms that consist of many cells are said to be multicellular e.g man.
In a multicellular organisms there are specialisation of cells and division of labour. That's each cell has it own specialised area, all the cells are not of the same kind like human being, we all have different cell and each cell performs different roles.
Let use human body for example,
In human body, red blood cell transport oxygen, white blood cell defend the body against infection, muscle cell brings about movement, spermatozoa fertilise the ova in reproduction and the nerve cells conduct impulses.
Note : In multicellular organisms all the cells of a body benefit from different action of different cells, that is, the cells are interdependent.
The cell which perform the same function may occur as a group of cells:
What am trying to say is, a cell of a similar structure performing the same action will combine together to form a group of cell.top↑
A group of cells which are similar in structure and perform the same function are called TISSUE.
Note: cell in a tissue is different from cell in a colony or a filament,
Cell in a tissue do not perform all functions of life in the organism, but only one or few of it. And you know that each cell in a filament or in a colony performs every or ALL function of cells in that organism.
Incase you are ask that what are the difference between cell in a tissue and cell in a colony and filament, that is the most important one, TISSUE performs ONLY ONE or FEW function while colony and filament perform ALL, other differences are:top↑
Tissue depends on other cells in the organism that's they are interdependent because if a tissue carries out or perform one function, such as support by xylem tissue, that tissue depends on other tissues for nutrition, reproduction and sensitivity etc WHILE cells in colony and filament are independent in many functions such as excretion, respiration, reproduction and nutrition etc.
Till next class, thank you for always reading.
feel free to ask me any question via the comment box or ask question page and I will be happy to answer your question and take the session again if necessary, your comment notifications is like a bank alert to me so don't forget to write something.top↑
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