The  

gymnosperms  

are  

the  

plants  

in  

which  

ovules  

are  

not  

enclosed  

by

any   

ovary   

wall.   

After   

fertilisation   

the   

seeds   

remain   

exposed   

and

therefore    

these    

plants    

are    

called    

naked-seeded    

plants.    

The

gymnosperms   

produce   

microspores   

and   

megaspores   

which   

are

produced    

in    

microsporangia    

and    

megasporangia    

borne    

on    

the

sporophylls.  

The  

sporophylls  

–  

microsporophylls  

and  

megasporophylls

–   

are   

arranged   

spirally   

on   

axis   

to   

form   

male   

and   

female   

cones,

respectively.  

The  

pollen  

grain  

germinates  

and  

pollen  

tube  

releases  

the

male   

gamete   

into   

the   

ovule,   

where   

it   

fuses   

with   

the   

egg   

cell   

in

archegonia.  

Following  

fertilisation,  

the  

zygote  

develops  

into  

embryo

and the ovules into seeds.