Which of the following defines a biome?

A biome is defined as a large geographic area characterized by specific climatic conditions, vegetation, and animal life. This encompasses a variety of ecosystems that share similar environmental characteristics, such as temperature, precipitation, and types of plants and animals.

In this context, the correct answer captures the essence of what a biome represents. A region containing similar ecosystems implies that within that biome, there are multiple ecosystems that coexist and share common features. For example, a forest biome may include various ecosystems such as temperate rainforests, tropical rainforests, and boreal forests, all of which have distinct but related ecological characteristics.

The other options describe concepts that do not encapsulate the definition of a biome. A small ecosystem focuses on a much smaller and specific ecological unit, rather than the broad concept of biomes. A type of soil is more narrowly defined and does not address the broader environmental context of a biome. A climatic phenomenon speaks to specific weather patterns but does not encompass the organisms and ecosystems that define a biome. Therefore, the choice that a biome is a region containing similar ecosystems accurately represents its definition in the study of ecology.