What is the volume of an irregular object if the initial volume in the graduated cylinder is 3.50 ml and it rises to 7.50 ml after putting the object in water> 4.00 ml 11.00 ml 7.50 ml

Answer is: the volume of an irregular object is 4,00 ml.
Volume is the amount of space the object occupies and can be finded immersing it in water in a container with volume markings and than see how much the level of the container changes (goes up). 
V(irregular object) = V(final volume) - V(initial volume).
V(irregular object) = 7,50 ml - 3,50 ml.
V(irregular object) = 4,00 ml.

Carbon based or cells?

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.