pollination and its types

pollination:its a transfer of pollen grain from anther to stigma of pistil called pollination   

both male female are non motile 

gamete have to brought together being fertilization

kinds of pollination:

on the basis of source of pollination  there are three types of pollination

1. autogamy

2.geitonogamy

3.xenogamy

 autogamy:

transfer of pollen grain from anther to stigma same flower of plant.

geitonogamy:

its shown in monocious plant.

transfer of pollen from anther of one flower to stigma of another flower but in same plant.

functionolly its cross pollination but mot a true cross pollination 

xenogamy;

in diocious plant  

. transfer of pollen from anther of one plant to stigma of another flower of diffrent plant .

.in this pollination  polliagent required.

its a true cross pollination 

variation ocour due to genetically .

agents of pollination:

there are two types of agents required for pollination 

biotic [most common]

abiotic[rare]

wind pollination:

pollen grain are non sticky so they can easily carried out by air 

well exposed stamen so high number of pollen grain are released 

water pollination:

limited about 30 genera mostly its depend on water fertilization 

movement of gemete is limited  .

#note; in  some plant like water hyanthis,water lily,emerge above the lavel of water so they pollinated by wind and insect  

for example .vallecineria fertilization takes pl

ace above water 

insect pollination:

 flower are large colourful and attractive also produce nectror. if flower are small then cluster of flower attract insect  through a diffrent colour of flower. 

example flies , beetle,wasp,,moth,honeybee,butterfly,etc