Tag: biology

After fertilization process, the different cells in the embryo sac develops to form several parts of the embryo. For instance, the outer integument forms testa, inner integument forms tegmen and ovary wall forms pericarp.

The haploid sperm and haploid egg combine to form a diploid zygote, while the other sperm and the two haploid polar nuclei of the large central cell of the megagametophyte form a triploid nucleus. It will later develop into the endosperm, nutrient tissue which provides nourishment to the developing embryo.

The fruit of the coconut is a large, dry drupe composed of a thin outer layer (exocarp), a thick, fibrous middle layer called as a mesocarp and a hard inner layer called as an endocarp that surrounds a large seed. A small, cylindrical embryo is embedded in the endosperm nutritive tissue just opposite the functional germination pore. The seed is surrounded by an outer brown layer called as the seed coat or testa.
Thus, the correct answer is option D.