Which of the following mutations would you expect to have the greatest effect on a living cell?

A. A mutation that changes a single base in a region of noncoding DNA
B. Energy release from plutonium
C. Consumptions of preexisting organic compounds

To determine which of the given options would have the greatest effect on a living cell, let's analyze each one:

A. A mutation that changes a single base in a region of noncoding DNA: Mutations in noncoding DNA regions typically have a lesser impact on the cell compared to mutations in coding regions, as noncoding DNA does not encode proteins. Thus, this mutation is unlikely to have a significant effect on the cell.

B. Energy release from plutonium: Plutonium is a highly radioactive element, and its energy release, usually in the form of radiation, can cause severe damage to living cells. This type of radiation can lead to DNA damage, disruption of cellular processes, and potentially cell death. Therefore, energy release from plutonium can have a significant and detrimental effect on living cells.

C. Consumption of preexisting organic compounds: While consumption of preexisting organic compounds does not involve any mutation or radiation, it can affect the cell's metabolism or energy production. Depending on the specific compounds and their concentrations, they may interfere with the normal cellular processes, leading to changes in cellular function or even cell death. However, the magnitude of the effect would depend on the specific compounds consumed and their concentrations.

Considering the possibilities, it can be concluded that option B, energy release from plutonium, would have the greatest effect on a living cell due to its potential to cause extensive damage via radiation.