Structure of Megasporangium

Structure of Megasporangium (Microsporophyll = Carpel) :-

also called Ovule 

=>  Structure Of carpel Differentiated Into 3 Part

i) Upper Recepetive Part = Stigma
ii) Elongated Tube Like Structure = Style
iii) Lower Swallon part = Ovary
These Are Arrange above the thalamus

@ Structure Of Megasporangium :-

Nucellus :-

 Protect Inner Part especially Embryo sac surrounded by two integument . Which present inner side called inner integument & Which present outerside called outer integument
* Portion of embryo where egg found called micropyle . Which help in entry pollen tube
* Back to micropyle end , there is broad part called Chalazal end
* Funicles is the part which help in Attachment of ovule from placenta

@ Types of Ovule :-

1. Orthotropous :-

Straight type ovule , in this ovule micropylar & Chalazal end found opposite to each other in straight line
- These type of ovule have Devoid of curvature

2. Anatropous :-

These type of ovule is completely inverted having 180 degree curvature of funicles
- In these type of ovule micropyle found near to hilum or faces toward placenta

3. Hemitropous :-

In this ovule Degree of curvature between orthotrophous & Anatropous , when body found right angle to funicles

4. Camplylotropous :-

In these type , ovule became somewhat curved so micropyle & chalazal come near to funicle , In these Nucellus became slightly curved & funicle attached to the middle of body of ovule

5. Amphidropous :-

in these type , nucellus & embryo sac both become curved & converted into horse-shoe shaped 

6. Circinotropous :-

these type ovule is orthotrophous in young condition , but due to elongation of funicle .it beome slightly inverted & funicle cover the total ovule because unilateral growth of funicle