What happens to the resistance of a wire as its length increases

Resistance increases with length because the electrons have further to go, so suffer greater collisions with atoms in the material. Look at these wires: Electrons moving through the short wire only feel resistance for a short time compared to the longer one. This means its resistance is less.

Explanation:

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 =