Final answer:
Organisms in a square mile of tropical rainforest are concentrated in a few locations, with high biodiversity and many endemic species, but are threatened by human activities.
Step-by-step explanation:
The question relates to the distribution and diversity of species in a tropical rainforest ecosystem. Thousands of species of organisms live in 1 square mile of tropical rainforest, and the true statement about those organisms is they are concentrated in a few locations. Due to high levels of biodiversity and endemism, these ecosystems often have a large number of species packed into small areas. Moreover, tropical rainforests are known for their important role as biodiversity hotspots, crucial for the development of new medicines and maintaining ecological balance. However, they are under threat from human activities such as deforestation, which can lead to significant biodiversity loss.