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.
Meiosis. Meiosis is used to make special cells-sperm cells and egg cells-that have half the normal number of chromosomes. It reduces the number from 23 pairs of chromosomes to 23 single chromosomes. The cell copies its chromosomes, but then separates the 23 pairs to ensure that each daughter cell has only one copy of each chromosome. A second division that divides each daughter cell again to produce four daughter cells.