Final answer:
The two major abiotic factors that determine a biome are precipitation levels and temperature.
Step-by-step explanation:
A biome can be determined by two major abiotic factors: precipitation levels and temperature. These factors play a crucial role in determining the type of vegetation and the organisms that can survive in a particular biome. For example, a desert biome has low precipitation levels and high temperatures, while a rainforest biome has high precipitation levels and relatively stable temperatures.