Final answer:
The egg in the ovule is located within the embryo sac, specifically the cell that is positioned at the micropylar end is the egg cell, which is poised for fertilization.
Step-by-step explanation:
The egg in the ovule is found in the female gametophyte, more precisely in the structure known as the embryo sac. Following megasporogenesis and megagametogenesis, the surviving haploid megaspore undergoes mitosis to produce an eight-nucleate, seven-cell structure. Of these cells, the one located at the micropylar end of the embryo sac becomes the egg cell. This egg cell is situated adjacent to two synergids and is ready for fertilization by the sperm cell upon the arrival of pollen.
The two-sexual-phase system in seed plants ensures that the megaspore which will become the egg cell undergoes meiosis before mitotic divisions, leading to the formation of the gametophyte. The micropylar end of the embryo sac is where the egg cell, essential for the process of fertilization, is located.