Answer:
A stem and leaf diagram has two parts, the 'stem' and the 'leaf'. In the stem, there are numbers in ascending order from top to bottom. In the leaf, there are numbers showing the next digit of the number in the stem. The leaf is to the right of the stem.
The function of a stem and leaf diagram is to summarize data in a way that separates numbers into different number categories.
Technically this can be answered in a number of ways. But in elementary biology the cell is considered to be the basic unit of life.