What causes the formation of graded beds of sediment?

In geology, a graded bed is one characterized by a systematic change in grain or clast size from one side of the bed to the other. Most commonly this takes the form of normal grading, with coarser sediments at the base, which grade upward into progressively finer onesI just learned about this in our rocks and minerals unit for science,

name and explain one of the event that occurs during meiosis that increases the variation in offspring even more than simple reproduction?

that is true   : ) hope this you