Answer: True
Step-by-step explanation:
In fact, binary fission (cell division) is the only way unicellular organisms produce new individuals.
Binary Fission (cell division) is a process by which a single cell splits into two cells to multiply. Since cell division makes exact copies of the parent cell, it is a form of asexual reproduction.
So, in summary, Unicellular organisms can increase in size (population) through cell division.