Final answer:
The number of amoebae in the colony after the 6th fission is (2^7 * 3^4), which corresponds to option d) in the given choices.
Step-by-step explanation:
Binary fission is the process by which amoeba reproduces asexually, splitting into two halves. In the initial stage of the colony, there are 18 amoebae. After the 6th fission, we can calculate the number of amoebae using the formula: 18 * (2^6). This gives us 1152 amoebae. However, we need to express the answer in the form of (2^m * 3^n). In this case, 1152 can be written as 2^7 * 3^4. Therefore, the number of amoebae in the colony after the 6th fission is (2^7 * 3^4), which corresponds to option d) in the given choices.