Answer:
Option A, Key stone
Explanation:
A keystone species plays a major role in an ecosystem as it is the species whose presence effects all other species in the ecosystem .In general a keystone species is always a dominant predator that feed on prey population. If it is removed, the prey population will explode and the population diversity will reduce. For example - bison, prairie dog etc.
Hence, option A is correct
Science has shown that smoking causes cancer. which is an example of how society responded to this information
Answer:
In the bloodstream
Explanation:
The metabolic breakdown of amino acids creates ammonia, which is especially toxic to the brain. The liver converts ammonia to urea, and it is then released into the bloodstream, where it travels to the kidneys and is excreted in the urine.