You should clarify what you want to measure about it: its diameter, mass, weight, color, etc. If you want to measure its diameter, that would usually be specified in microns (= micrometers).
No. The closest metric unit is the meter.
centimeter
You would measure that in grams, or milligrams.
The basic metric unit of measure for length is the meter (m).
meeters?
meters There is no special unit for the size of bacteria, so traditional systems of length are used. As most people who care about bacteria enough to measure them are scientists, and most scientists use metric (the better to understand each other), the metric system is used. Now, the basic unit of length in the metric system is a meter, but that is much to big to measure a bacterium with. Conveniently, metric units come with a series of prefixes to express multiples or fraction of a unit (you may know of centimeters, which are hundredths of a meter, and kilometers, which are a thousand meters) In general, bacteria will be measured in micrometers, which is to say millionths of a meter. In general, a bacterium will measure anywhere from one to ten nanometers.
You would use the metric unit "liters" to measure the capacity of a hot water tank.
You would typically use the metric unit of centimeters to measure the growth of your hair.
You would use the metric unit "kilograms" to measure the weight of a bag of groceries.
kilograms
You would use the metric unit "kilograms" to measure the weight of a sack of peaches.
You would use the metric unit "kilograms" to measure the mass of a wardrobe.
The metric unit used to measure a picnic cooler would be liters (L) for volume.
The metric unit commonly used to measure height is the meter. So, you would measure the height of Big Ben in meters.
meters
Millimeters
Litres.