Final answer:
Yes, exotic species can threaten native species. This is due to the fact that the native species often lack natural defenses against these foreign organisms. Increasing global trade and transport make introductions of these exotic species, which can disrupt ecosystems and threaten biodiversity, more frequent.
Step-by-step explanation:
The statement 'Exotic species can threaten native species because the native species do not have any natural defense against the alien species' is True. Exotic species, also commonly referred to as invasive species, are organisms that have been introduced into an area where they didn't evolve. When such a species is introduced, it can dramatically disrupt the local ecosystem and become a threat to native species.
These threats can happen in multiple ways including competition for resources, predation, or disease. For example, the European starling in the United States may compete with native bird species for nest holes. Also, invasive species like the purple loosestrife and zebra mussel threaten certain aquatic ecosystems. These species have characteristics that give them an edge over the native species, often because the native species have not developed defenses against these exotic competitors, predators, or diseases.
Furthermore, due to factors such as increased human mobility and global transport, introductions of exotic species are becoming more damaging to native ecosystems around the world. Therefore, it's essential to control the introduction and spread of exotic species to preserve biodiversity and sustain the health of our ecosystems.
Learn more about Exotic Species