The aura can be in the form of prismatic colors, flashes of light, and sometimes stars. They usually last about 20 minutes and then go away. If these flashes or lines of light occur without a headache, it is called an ophthalmic migraine, or a migraine without a headache.
In gymnosperms and flowering plants, the megaspore is produced inside the nucellus of the ovule. During megasporogenesis, a diploid precursor cell, the megasporocyte or megaspore mother cell, undergoes meiosis to produce initially four haploid cells (the megaspores).
Sporophytes (2n) undergo meiosis to produce spores that develop into gametophytes (1n) which undergo mitosis. Describe the role of the sporophyte and gametophyte in plant reproduction. The diploid stage of a plant (2n), the sporophyte, bears a sporangium, an organ that produces spores during meiosis.