growth and development

Growth and Development of Ovule and Ovary

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

Growth and Development of Ovule

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

Gowth and Development of endosperm

            The endosperm grows and develops earlier, compared to the embryo. The endosperm is rich in nutrients and it servers as food storage which is utilized for the growth and development of the embryo. In most monocotyledons,the nutrient reservers is put in the cotyledon before seed grows and developes further.

Gowth 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 function as a connector between the embryo and the outer layer of the ovule. It also allows nutrients flow from the mother plant or the endosperm. Apical cells develop into a proembryo. This is followed by embryo`s development. In then develops a stem and roots.

Structure of mature seed

            During its maturation, the seed is dehydrated until water content is only about 5% to 15% of its weigth. Then, the embryo stop 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 ar formed. Epicotyls are located above the cotyledon. The tip of the epicotyls is called the plumule, which is foliage of leaves. Hypocotyls are located below the cotyledon. They end at the radical. 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 coleorhizae and coleoptiles. Coleorhizae protects the radical and the coleoptiles protects leaves and stem primordia