The exact number of biomes depends on who you ask.
The exact number of depends on who you ask. Different people and/or organizations classify biomes in slightly different ways. Some will say that there are five some and some more.
It is common to state that there are five major biomes: deserts aquatic forests grasslands and tundra. Read more about them here.
NASA lists seven biomes: tundra shrubland rainforest grassland desert temperate deciduous forest and coniferous forests.
Others may say there are nine biomes: marine freshwater savanna grassland taiga tundra desert temperate forest and tropical rainforest.
More examples of biome classifications are below.
To conclude the number of biomes depends on who is classifying them and the number of biomes depends on this.