Answer :
Final answer:
Keystone species are critical for main taining ecosystem balance and biodiversity; their removal leads to drastic and negative changes in the ecosystem.(option c)
Explanation:
Keystone species are critical for maintaining the balance of nature and biodiversity. Their role is so significant that their removal may cause drastic changes in the ecosystem. For instance, the removal of the keystone species Pisaster ochraceus, an intertidal sea star, from its natural habitat led to the overpopulation of mussels, ultimately altering species composition and reducing biodiversity.
Similarly, the banded tetra, a fish that supplies essential nutrients like phosphorus in tropical streams, is another example of a keystone species whose absence would significantly affect the ecosystem. Hence, keystone species sustain the ecological community's structure and maintain biodiversity, highlighting their fundamental importance.
