Economical importance of bryophytes

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ECOLOGICAL IMPORTANCE OF BRYOPHYTES Mosses and Bryophytes are the first organiasms to colonise rocks. They colonise rock by acidic secretion. This acidic secretion is due to the death of mosses. When the rock is decomposed it helps in soil formation. Therefore New soils are formed. The soil act as binders.  It prevent soil erosion. The water retention capacity of the soil is high ie, water holding capacity of the soil is high.  This reduces surface water run-off which prevent soil erosion. Bryophyte helps in the recycling of nutrients. ECONOMICAL IMPORTANCE OF BRYOPHYTES. 1) SPHAGNUM Sphagnum has high absorptive power with antiseptic property. This can be used to replace cotton in bandages. 2) MERCHANTIA   Mercahntia cures pulmonary tuberculosisand affliction (pain) in liver. Antibiotic substances are also extracted from bryophytes. it also acts as antiseptic, and as preservative POLYTRICHUM Polytrichum dissolove stone in kidney and in gall bladder. 3) IN RESEARCH It is used in the fie
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Discovery of cell and cell theory ( cell is the structural and functional unit of life)

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Disvovery of cell
All animals and plants consist of certain structural units. Such a concept was originally put forward by Aristotle (384-322 B. C) . For these units, a term cell( in Gr., kytos- cell, cella_ hollow space) was used by Robert Hooke in 1665,he observed these for the first time in a piece of cork under a primitive microscope which was a dead cell so, that's cytoplasmic contents were lost and the cell wall only remain so, it was look like hollow space( ie., like rooms of a house separated by the walls) so, he called them cell. Later, cells in the form of cavities with cellulose walls were observed in different plants by Grew and Malpighi. In 1674,Leeuweenhoek also first observed the living cells and some organization within these cells. 

Cell theory
   The structural unit called cell, is  now known as the unit of life and the concept that the cell is basic unit of life is known as cell theory. At the Beck of 19th century several workers including H. J Dutrochet gave the idea of cell theory, the credit for formulating cell theory is normally given to a botanist ( worked on plants cells)M.I  Schleiden and a zoologist ( worked on animals cells) T. Schwann who clearly outlined the basic features of this theory in 1839. However, they took t old ideas and presented a theory. It says that

- all living organisms are made up of cell maybe with single cell or many cells. 
- the functions of organisms due to the interaction of cells. ( ie if the organisms doing any work there the cells are doing that work) 
- a cell is a mass of protoplasm containing a nucleus , bounded membrane and cell Wall. 
- cell could be arises spontaneously. 

Modern cell theory or cell principles
     R. Virchow in 1958 extended the cell theory and suggested that an additional features of cell theory should be all living cells are arise from pre- existing living cells ( omnis  cellula  e cellula,or continuous line of cells generation from the very beginning of life ( Theory O linease)) etc. Later, Louis pasteur, gave experimental evidence to support Virchow' s extension of the cell theory. There are two Main components of cell theory ie 

- all living things are composed of cells and there products
- all cells are arise from pre- existing living cells by cell division. 
Some other components are
-  cell is also the unit of function like reproduction and heredity. 
- each cell is capable of regulating it's vital process,
-life can pass from one generation to the another . 
- working of cell is controlled by nucleus ( who  carry genetic material DNA) 

 Exceptions of cell theory
 A special difficulty is faced when we apply the concept of cell theory to such 
- there are many cells which don't have nucleus eg., bache, mycoplasma, mammalian RBCs, sieve tube cells in plants. 
- virus don't have a determine cell shape( but in cell it was state that the cell have cell membrane or cell wall) , it's a sub- cellular an sub- microscopic obligate parasites who strongly need a living host  to complete their life processes. It can show some living properties. 
- many fungi( Rhizopus), algae ( Vaucheria) and protozoan ( Paramecium) that contain many nucleus . 

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