Growth and Development of Ovule and Ovary

Angiosperms undergo double fertilization. Double  fertilization  produces  a  zygote  and  an endosperm.  Afterwards,  the  ovule  develops into  a  seed  and  an  ovary  into  a  fruit  that protects  the  seed(s). 

Growth  and  Development of Ovule

The  ovule  grows  and  develops into  a seed. The zygote and endosperm  are  in it.  The zygote  continues  to  grow  and develops in to an  embryo

Growth  and  development of endosperm 

The endosperm grows and develops earlier, compared to the embryo.  The endosperm is rich in nutrients and it serves as food storage which is  utilized  for  the  growth  and  development of  the  embryo.  In  most  monocotyledons, the  endosperm  is  filled  with  nutrients  for germination.  In  several  dicotyledons,  the nutrient reserves is put in the cotyledon before seed  grows  and  develops  further. 

Growth  and  development  of embryo 

Growth  and  development  of  the  embryo is  begun  with  zygotic  cleavage  by  mitosis to  produce  basal  and  apical  cells.  Basal  cells develop  into  a  suspensor.  The  suspensor functions  as  a  connector between  the  embryo and  the  outer  layer  of  the  ovule.  It  also allows  nutrients  flow  from  the  mother Plant or endosperm apical cell develops into  a proembryo  that attaches  to  the suspensor the cotyledon start to emerge in the form of a protusion on the pro embrio. This Followed by embryo development. It then develops. It the develops a stem and roots. Look at Picture 1.3 

Structure  of mature  seed 

During its maturation, the seed is dehydrated until water content is only about 5% to 15% of its weight. Then, the embryo stops developing until the seed germinates. A mature seed contains an embryo that is surrounded by a cotyledon, or an endosperm, or both, . The seed is protected by a seed coat (testa). 

Dicotyledon plants have two cotyledons. In their embryo’s development, epicotyls and hypocotyls are formed. Ehicotyls are located above the cotyledon. The tip Of the epicotyl is called the plumule, which is the foliage of leaves. Hypocotyls are located below the

cotyledon. They end at the radide. Monocots have only a single cotyledon. In some monocots, the cotyledon is called a scutellum. It is thin and the endosperm suppresses where it is positioned. The scutellum absorbs nutrients from the endosperm during germination. The embryos of grass plants are surrounded by coleorhiza and coleoptile. Coleorhiza protects the radicle and the coleoptile protects leaves and stem primordia. Look at Figure 1.4. 

Growth and Development of Ovary 

When an ovule develops into a seed, the ovary develops into a fruit. The fruit protects the seed when it is dispersed by wind or animals. Fruits starts to develop after pollination. 

Pollination stimulates the hormonal change that triggers the development of an ovary. The wall of an ovary develops into the pericarp (the thickest part of the fruit wall). When an ovary develops, other parts of the flower fall out. If pollination does not occur, the fruit will not develop and all parts of the flower die away and fall from its stalk.

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