Fact 1: Fission takes place when an animal divides into two parts.

Fact 2: An isotope capable of undergoing fission is called a fissile isotope .

Given the two facts above, answer the question "What are capable of dividing into two parts?" with the following options: 
- epidermis and dermis
 - colors of the spectrum
 - rays or beams
 - bacteria
 - fissile isotopes
 - critical organs
 - objects that have mass
 - the body's largest organ


 

     fissile isotopes    