<span>Damming a river has a variety of effects on the freshwater ecosystem, more than just altering the flow from A to B. Dams create calm bodies of water, changing overall temperature regimes and sediment transport, leading to conditions which tend to favour generalist species. Loss of specialist species, particularly endemics, changes the community structure and leads to biotic homogenization. A dam will withhold sediment in the reservoir, not just decreasing the amount of substrate available to local freshwater species, but even impacting diadromous, estuarine and marine species much further downstream. The competition between resident species for food and breeding sites will increase as damming isolates populations, and perhaps more importantly, damming completely restricts migratory fish species. Isolation may lead to decreases in genetic diversity and therefore puts species at greater risk from disease. All of these effects may be exacerbated by changes in the surrounding land use. Overall, damming river flow will lead to both a loss of native species, but also an increase in exotic species which are more likely to become established in degraded habitats. For this reason, dams are one of the greatest global threats to freshwater biodiversity.</span>
Answer:
It is called mimicry when a living thing copies the appearance of another living thing as a means of protection.
Explanation:
Mimicry is used primarily by living things as a means for protection and to decrease the chances of the living thing being killed. For example, a frog that is prey to a toad could have bright colors (bright color frogs are often poisonous) that don't mean anything to the frog and it's species, but to the toad, the frog is poisonous and should not be eaten, so the toad does not eat the frog because it is brightly colored.
Without mimicry, the frog would have been eaten because it wouldn't have had looked like a poisonous frog, or something that the toad would avoid.
D. Parasitic will be you answer.
It looks correct to me. Good job
