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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what is NUCLEUS , SIGNIFICANC, NUMBER, SHAPE AND SIZE , notes...

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Significance of nucleus

    Robert Brown for the first time in 1883 discovered a prominent body with in the cell and termed it nucleus ( from the Greek word karyon) . A German botanist J.Hammerling , demonstrated in 1934 that the nucleus determine the characters of the cell and ultimately the characters of the individual.he conducted a certain experiment using two species of alga ,Acetabularia. the two species are differ in shape and their caps. The Nucleus of the two species are situated in the rhizoid at the bottom of the stalk.if the caps are cut off,it will develop again and again and it's shape are that of the original type. However,after removing the caps the stalk of two species grafted with the rhizoids of the another species.then he observed that the caps were develope according to the nucleus.when both of the nucleus were grafted with the single stalk then the cap develoed intermediate type.this experiment demonstrated for the first time that characters of an individual are controlled by the nucleus of the cell.this controlling attribute of the nucleus is now we established and known to be due to the presence of chromosomes in this organelle.

Number
    
     Generally there is a single Nucleus per a cell( mononucleate stage) , but in some cases there is more than one nucleus ( polynucleate stage)  is found in one cell.there may be many nuclei in a syncytium, which is formed due to the fusion of cells.a similar multinucleate situation found in coenocytes condition commonly found in plants, formed by the nuclear divisions with out cytokinesis.

Shape and size

    There are variations with respect to the shape and size of the nucleus.it May be spherical, oval to flattened lobe or irregular in shape.the shape of the nucleus also depends on the cell, branched nucleus are sometimes found in glandular cells.size of the nucleus also vary depending upon the type of cell involved but also according to the activities of the cell.the nucleus will be larger in active cell and smaller in a resting cell.

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