Whether eye dilation during an exam is necessary depends on the reason for your exam, your age, your overall health and your risk of eye diseases. The eyedrops used for dilation cause your pupils to widen, allowing in more light and giving your doctor a better view of the back of your eye. Eye dilation assists your doctor in diagnosing common diseases and conditions, possibly at their earliest stages. They include:
In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell.
  The purpose of meiosis is to divide the number of chromosomes in gamete cells (spermatazoa and oocytes) to the haploid number (23 chromosomes). Meiosis ensures the prope â¦ r number of chromosomes to form a zygote, which is 46 chromosomes (diploid number), during fertilization.