Advanced Placement (AP) European History Practice Exam

The success of Old World forage grasses in new environments can be attributed to their ability to thrive in conditions that involved open sunlight and close cropping. This adaptability allowed them to establish themselves effectively in diverse settings, especially when introduced to different climates and ecosystems. In contrast to other characteristics, being tolerant of open sunlight enabled these grasses to photosynthesize efficiently in environments where sunlight was abundant. Their resilience to close cropping also meant that they could withstand grazing and clipping, allowing for regeneration after being consumed. This adaptability not only promoted their spread but also supported agricultural practices focused on livestock grazing, making them valuable in pastoral systems. Understanding this adaptability highlights why these grasses were more successful than others that required specific soil conditions, preferred shaded areas, or were heavily dependent on local rainfall. These factors would have limited their establishment and persistence in new environments where conditions could vary significantly.