In this you will study about by plant ovule and it's types

1. Name –KIRTI RAWAT
BSC 3RD YEAR
FRAME COLLEGE FOR GIRLS

2. CONTENT
 TYPES OF OVULE
 MEGASPOROGENESIS
 DEVELOPMENT OF FEMALE GAMETOPHYTE
(EMBRYO SAC )

3. OVULE
 The plant ovule is a part of female reproductive
organ
 It is that part of plant reproductive cells are
made and kept and these cells develop into
seeds after fertilisation
 These seeds later ripens and turns into an adult
plant

4. Structure of ovule

5.  FUNICLE ;-
 It is a stalk shape structure
 The site where funicle is attached with ovary
is called hilum
 It is attached with placenta
 It connect ovule with ovary with ovary by
placenta
 INTEGUMENT;
 It is covering of ovule
 It forms seed coat

6.  NUCELLUS ;
 This is the largest part of ovule
 It contain embryo sac and nutritive tissue
 It is found between embryo sac and inetgument
 It is made up of parenchymatous cells where food is
stored
 EMBRYO SAC;
 It is the main part of ovule where fertilisation occurs
 MICROPHYLE ;
 The site where inetgument is absent
 It’s a small pore from this pollen tubee enter in
embyo sac

7.  CHALAZA ;
 It is opposite pole of micropyle
 TYPES OF OVULE
 There are six types of ovules based on there
shapes ;
 1 atropous
 2 anatropous
 3 hemianatropus
 4camplyotropous
 5 amphitropous
 6 circinotropous

8. ATROPOUS;
. In this funicle ,chalaza,and micropyle are situated on one axis
example ; black pepper

9. HEMI ANATROPOUS ;
. the ovules takes the shape of right angle in the relation to its funicle
. It looks like the ovule is lying on its side
example; rananculus

10. ANATROPOUS ;
. It is inverted
.micropyle lies close to hilum
example ;82% angiosperm

11. CAMPYLOTROPOUS ;
.the embryo sac is slighty curved
. Example ; mustard ; sunflower

12. AMPHITROPOUS ;
the ovule is at 180degree
example – butomas , poppy

13. Circinotropous ;
. The shape of it is the most distict of them all
.the funicle is so long that it create a full circle around the ovule and its
micropyle ultimately points upward
example ; cactaceae family

14. Megasporogenesis
 Formation of megaspore by megaspore mother cell
(MMC)is called megasporogenesis
 Formation of megaspore ;
 during development of ovule a cell from nucellus
become large and cytoplasm become dense and this
cell is called archaesporal cell
 Now this cell divides and form two cells
 1 primary wall cell
 2 primary megasporogenesis pr megaspore mother
cell (2n)

15.  Megaspore mother cell divide meiotically and form 4
megaspore and this strucutre is called megaspore
tetrad
 3 megaspore are inactive which are present towards
micropyle pole
 active megaspore is located on chalaza pole
 inactive megaspore degenrate after some time and
only 1 megaspore remains

17. Development of female
gametophyte (embryo sac )
structure of embryo sac ;

18.  Developed female gametophtye is called embryo sac
 In most of the angiosperms embryo sac is called 7
celled and 8 nucleated structure 3 cells which are
located on chalaza pole are called antipodal cell
 A binucleated cell which is located in the centre of
embryo sac is called central cell
 Central cell form a triploid endosperm with the fusion
of male nucleus
 A group of 3 cell [ 2 synergids +1 egg cell ] are
located on micropyle is called egg apparatus

19.  DEVELOPEMENT OF FEMALE GAMETOPHYTE;
 In this process megaspore cell become large
 Now nucellus of the cell divides by mitosis
 now these nucleus move towards their pole . Now 1
nucleus is situated at chalaza pole and other
nucleus is situated in micropyle pole
 Now this nucleus divides continueously 2 times by
mitosis
 Now every pole have 4 nucleus after this 1 nucleus
from each pole move towards middle plate
 after this all incident a 7 celled and 8 nucleated
structure is formed which is called female
gametophyte

21. Thank you for
watching ….My
presentation