Final answer:
The biome characterized by dominating grasses and known as the 'world's breadbaskets' due to extensive grain crops like wheat is the temperate grassland.
Step-by-step explanation:
The temperate grassland biome is characterized by grasses as the dominant vegetation. This biome is often referred to as the world's breadbaskets due to the vast cultivation of grain crops, particularly wheat. In temperate grasslands, annual precipitation ranges from 25 cm to 75 cm (9.8-29.5 in), which is relatively low and contributes to the limited presence of trees, typically only found near rivers or streams. These grasslands experience periodic fires and grazing, which maintain their open landscapes. The soils in temperate grasslands are extremely fertile due to the dense network of roots and rhizomes below the surface that replenish the soil's organic material when they decay.