Economical importance of bryophytes

-
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
1 comment

what is haplontic and diplobiontic life cycle , notes

-
Life cycle of algae

   The growth and development of alga passes through a number of distinct morphological and cytological changes or stages. the sequence of these orderly changes is said to be life cycle or like history of algae.   
              Ie., It's from one zygote generation to the next orr one gametophytic generation to the next is said to be life cycle.

Haplontic life cycle.

     The plant body is haploid bears haploid gametes in the gametagoniun . the gametes are fused and form a diploid zygote , which is only the diploid stage or phage during their life cycle. Later the zygote nucleus divides meiotically and form four haploid meiospore . Each meiospore develops into new individuals .this there is alternation of the haploid gamete with diploid zygote.
    Here gametophytic generation is dominant over sporophytic generation.   Found in motile unicellular form ex., Chlymadomonas, Oedogonium,Volvox ,Chara etc.

Diplontic life cycle.

      Diploid plant body bears diploid sex organs , reduction division takes place in these sex organs at the time of gamete formation,after gamete fusion the diploid stage is re-establish in the form of zygote.the zygote gives rise to a diploid plant body.  Only the gametes represent the haploid stage during the life cycle.thus there is an altercation of generation of diploid zygote with haploid gametes.
    Here sporophytic generation is dominant over gametophytic generation.fiund in some members of chlorophyceae ( cladophora etc) ,phaeophyceae( fucus etc) and nearly all bacillariophyceae.

All the best....

Comments

Post a Comment

Popular posts from this blog

Cell structure and cell wall of algae notes

-
Image
CELL STRUCTURE  CELL WALL FLAGELLA CELL STRUCTURE   On the basis of their organization algal cell maybe differentiate into prokaryotic, mesokaryotic, and Eukaryotic. Prokaryotic are primitive found in Cyanophycean algae characterised by absence of membrane bound organelles, absence of basic protein called histones in DNA.                A Eukaryotic cell have a well organized nucleus and membrane bound organelles.                Mesokaryotic cell has a nuclear membrane and chromosomes(Eukaryotic characters), basic proteins are absent and nucleus division like prokaryotic type (prokaryotic characters). Fou8 in members of Dynophyceae.  1.CELL WALL       Most of the non motile unicellular and multicellular algae possess a typical cellulosic cell wall of non living matter out side the cytoplasmic membrane. It composed of pure or mixed carbohydrate ( cellulose, mucilage, pectin etc.) and substances like alginic acids, fucoidin,, fucin and hemicellulose are present in brown algae
Read more

what is Haplodiplontic life cycle ( triphasic)

-
Image
Triphasic life cycle.       In triphasic life cycle there is a succession of there generation ie may be two haploid generations and one diploid generation or one haploid generation with two diploid generations.it is of following types ie ,   I.Haplobiontic type ( 2 haploid + 1 diploid)         In some rhodophyceae like Batrachospermum two well developed haploid phase are present and the diploid phase is represented by only zygote.                 The haploid plant body bears sex organs ( spermatogonia, carpogonia ) haploid gametes ( sperm and egg)  are formed in these sex organs,a diploid zygote is formed by the fusion of two gametes.the nucleus of the zygote divides meiotically to form four haploid carpogonia ,  they later develop into carposporophyte  generation ( a haploid generation) . the carposporophyte bears carpospores , after liberation carpospores are germinate into heterogeneous chantransia stage ( resting stage) , after this stage a new gametophytic
Read more

Mechanism of enzyme action , active sites, interactions, enzyme specificity, lowering of activation energy, notes

-
Image
Mechanism of enzyme action       The cellular environment normally does not favour a chemical reaction as the biological molecules are quite stable in aqueous environment in the cell at fixed temp and pH. The activation of substrate is prerequisite to overcome the transition state and to proceed the reaction in desire direction.the activation of the substrate is done by the enzyme. How the enzyme decreases the activation energy ,It will be discussed below.    Active sites       The enzymes have a ability to bring the substrate closer and in suitable orientation so as to favour the formation of ES ( enzyme substrate complex ) , the substrate binds to the enzyme at specific place or site called active sites.it is so designed that it will occupy by only the selected molecules, these sites have specific amino acid residues which establish covalent links with the substrate, this links provides the formation of transition state and hence lower the activation energy.each enzyme have different
Read more