BIO1022 Lecture Notes - Lecture 11: Double Fertilization, Endosperm, Eudicots
13 Oct 2018
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Document Summary
After successful pollination and double fertilisation, a seed begins to form. During this process, both the endosperm and the embryo develop. When mature, a seed consists of a dormant embryo surrounded by stored food and protective layers. After double fertilisation, the triploid nucleus of the ovule"s central cell divides, forming a multinucleate (cid:1688)supercell(cid:1689) that has a milky consistency. This liquid mass, the endosperm, becomes multicellular when cytokinesis partitions the cytoplasm by forming membranes between the nuclei. Eventually, these naked cells produce cell walls, and the endosperm becomes solid. In grains and most other species of monocots, as well as many eudicots, the endosperm stores nutrients that can be used by the seedling after germination. In other eudicot seeds, the food reserves of the endosperm are completely exported to the cotyledons before the seed completes its development; consequently, the mature seed lacks endosperm.
