An onion cell is 2 micrometers long. how many are needed to line up end to end across a microscope slide 8 centimeters in diameter?

The number of onion cells that are needed to line up end to end are 40,000

Explanation:

We are given:

Length of microscopic slide = 8 cm

Length of 1 onion cell =   (Conversion factor: )

To calculate the number of onion cells required, we divide the length of microscopic slide to the length of 1 onion cell, we get:

Hence, the number of onion cells that are needed to line up end to end are 40,000