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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MORPHOLOGY OF A TYPICAL ANGIOSPERMIC PLANT

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MORPHOLOGY OF A TYPICAL ANGIOSPERMIC PLANT.

Plant body of an angiospermic plant consists of MAIN AXIS.

Main axis
1) it may be branched or unbranched.
2) it is differentiated into TWO parts.
                   I) root system
                         Underground part.
                         Example : roots.

                  II) shoot system
                        Aerial part. (above ground)
                         Examples;
                          1) stem
                          2) leaves
                          3) buds
                          4) flower 🌺
                          5) fruit
                          6) seeds
Root
  It is the non green underground part of the plant.
Function.
1) anchors the plant, penetrate soil.
2) absorbs water and minerals ion.
3) crucial to plant nutrition.

Types of roots.

1) primary root.
I) develops directly from radicle.

2) secondary root.
I) when primary root bears many lateral branches, is called secondary root.

II) grow in acropetal succession.

iii) young lateral root is found nearest at the appex.

iv) older root - further back from appex.

3) tertiary root.
i) secondary root further branch and rebranch to form tertiary root and rootlets.

Root cap is called calyptra
Growing tips of all root are protected by root cap.
Out of root hair, a buft of unicellular cells are found called root hairs.

2. Stem
-Develops from plumule of the seed.
-Overground.
- differentiated into nodes and internodes.
Nodes: 
A node is a place where leaves or branches arises.
Internodes 
Distance between two adjacent nodes

Function of stem.
i) stem bear lateral branches, buds, leaves, flowers and fruits.
ii) may bear defence organ like spines, prickles and stiff hairs.
iii) stem exposes organ (leaves, flower 🌺, fruits) for to carry out their functions.
iv) stem conducts materials (water, minerals) required for plant ☘️.

LEAF 🌿
- Lateral outgrowth arises from its node of stem or its branches.
- collectively all leaves are called foliage.
- leaf have
   1) leaf base
   2) petiole
   3) lamina
- leaf lamina contains veins and veinlets.

FUNCTIONS
i) photosynthesis
ii) transpiration
iii) gas exchange

BUDS
- buds are condensed (under-developed) young shoot.
- on the basis of positions,  BUDS divided into three types
1) apical buds (terminal) 
Function
i) increase height

2) axillary buds (lateral)

function
I) form lateral branches

3) acessory buds
Function
i) give rise to stem modification

5) flower 🌺
- reproductive shoot, meant for sexual reproduction in angiosperms.
- a complete flower 🌺 have four whorls
1) Accessory whorl (calyx,corolla)
2) reproductive whorl ( androecium, gynoecium)

1) calyx 
   - outermost whorl 
   - collection of SEPALS
   - usually green
2) corolla
   - collection of PETALS
   - present inner to calyx
   - bright color of petal attracts 🐝 insects,bee (pollination)

     (above two are accessory whorls)

3) androecium
   - collection of STAMENS
   - male sex organ
   - stamen has 3 parts

      1) filament
      2) connective
      3) anther
4) gynoecium
   - female reproductive organ of plants
   - collection of CARPELS.
   - it has 3 parts
    1) STIGMA  (recieves pollen)
    2) STYLE 
    3) OVARY (bears ovule ; ovule encloses embrayo sac, which contains EGG CELLS)

     (Above two - reproductive whorls)

6) fruit 🍑
 - After fertilization, ovary develops to fruit.
 - fruit encloses many seeds.

i) True fruit
 - a true fruit develops from fertilized ovary and contains functional seeds
Eg, mango 🥭, maize 🌽,grapes 🍇
  Example - Mango 🥭

Hii) FALSE FRUIT
 - also called pseudocarps.
 A false fruit develops from floral parts other than ovary.
Example ; thallamus in Apple 🍎

7) seeds  
 - ovules after fertilization develops into seeds
- seeds have  i) seed coat
                       ii) embrayo
 - embrayo is the future plant ☘️
- it consists of one or two COTYLEDONS      attached to embrayo axis (tigellum)
- one end of tigellum called
 PLUMULE (grows into SHOOT)
- other end called RADICLE (grows into ROOT)



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