Question

Keystone species are those species _____. see concept 54.2 (page 1223) keystone species are those species _____. see concept 54.2 (page 1223) that have the most biomass in the community that provide important foods and medicines that live primarily on or under rocks and stones with the largest number of individuals in a community whose absence would cause major disruption in a community

Answer 1

A keystone species is crucial for the ecological community's structure and biodiversity. They have disproportionate impacts on their ecosystem relative to their abundance. The removal of a keystone species can lead to major ecological disruptions.

Step-by-step explanation:

A keystone species is a species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass. Such species are crucial in maintaining the overall health and balance of their ecosystems. For instance, the intertidal sea star, Pisaster ochraceus, is a known keystone species in the northwestern United States. When it is removed from its environment, mussel populations, which are their natural prey, grow exponentially, thus disrupting the species composition and reducing biodiversity. Similarly, the banded tetra, a tropical stream fish, is another keystone species because it provides nearly all the phosphorus needed by other species in the community. If such keystone species were removed, the impacts on their ecosystems would be profound, leading to major changes in the community structure and potentially causing loss of biodiversity.

Answer 2

The correct answer is the species whose absence would cause major disruption in a community.

The keystone species are the ones that are ''keeping the ecosystem together''.
They might not be the most abundant species or a species on the top of the food chain, but they are the ones that have the strongest effect on the ecosystem.
The keystone species can have this role because they present an important link in the food chain, their presence changes an aspect of the habitat, they introduce a new resource in the ecosystem etc.