The Angiosperm Plant Body Structure and development –Formation of embryo –Mature embryo and seed –Embryo to adult

The structure of the Flower

Fertilization detailed

In most angiosperms, the ovule consists of three layers of tissue: 1.Integuments - two outer layers of diploid (2N) tissue that will develop into the seed coat. 2.Nucellus - the wall of megasporangium, also diploid (2N). 3.Embryo sac - also call the megagametophyte of angiosperms, consists of only 7 cells. Contains 8 haploid nuclei in all.

“Polarity” -Apical- basal pattern - Radial pattern

Embryo development Orderly cell division Differentiation leads into two distinct parts –Embryo proper –The suspensor Before this stage is reached the developing embryo is referred to as the proembryo Becomes food nourishing component

Development of the embryo of a monocot (arrowhead)

Stage of embryo development preceding cotyledon development Globular stage- embryo proper is spherical Heart stage (dicots only)- seed leaf (cotyledon) development Torpedo stage- apical basal pattern just prior to germination

Pre Globular stage- proembryo

Embryo proper will become - meristemic tissue Future Epidermis Future Ground meristem (ground) and Procambium (vascular)

Forms the seed coat

Twin embryo development- embryo proper limits the dev of suspensors

(Precursor to vascular)

(nucellar tissue) (Embryonic root)

Lets look at Seed of some common dicots and monocots Garden bean Castor bean Onion Maize

Mature grain or kernel of Wheat Monocot or dicot? Grass embryo

Protective layer of radicle and plumule -First bud of radicle