A sample of ideal gas is in a cylinder with a movable piston. 600J of heat is added to the gas in an isothermal process. As the gas expands, pushing against the piston, how much work does it do

heat the gas and measure the pressure

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =