Answer:
The starfish Pisaster ochraceus is a keystone species in the rocky marine intertidal communities off the northwest coast of North America. This predatory starfish feeds on the mussel Mytilus californianus and is responsible for maintaining much of the local diversity of species within certain communities. A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. This means that if the species were to disappear from the ecosystem, no other species would be able to fill its ecological niche.
Explanation:
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Hello. Your question is incomplete. However, I managed to find a question exactly like yours on the internet and managed to realize that you forgot to say that your question asks you to give an example of the statement presented above.
Answer:
A major disturbance from which the ecosystem was able to recover completely was the disease that almost wiped out all of Ireland's potato in 1840.
Explanation:
You may have heard of the Irish Potato Famine, which was a time when the Irish population lived very difficult days, after an illness that almost decimated the country's potato plantations.
The potato was the main source of food for the Irish, but in 1840, a fungus called Phytophthora infestans, managed to infect almost all potato plantations in the country, preventing the potato from being harvested and could be consumed. This created major economic and social problems in Ireland, as people suffered from hunger, poverty and the diseases that arose, which caused many Irish people to immigrate to other countries, or to die.
The fungus plagued the ecosystem for years and only started to decrease in intensity in 1850, once the ecosystem started to recover. Currently, although the pest still exists, the Irish ecosystem is completely recovered and the pest is controlled and is unable to make such an impact.
The answer is reflexes. Reflexes are usually involuntary muscle movements that happen almost instantaneously in response to stimuli. A reflex is made possible by neural pathways called reflex arcs which can act on an impulse before that impulse reaches the brain. It is a survival mechanism evolved by the body used in the objective to escape danger.
Answer:
births - deaths = growth
Explanation:
(births - deaths) + (immigrants - emmigrants) is what you would normally use to calculate the growth of a population, but because they can't move, you can cut out the immigrant and emmigrant part of the equation.
