A study was completed to the effect of the banded tetra on other plant and animal populations in its tropical stream environment the scientists looked at the population level of other species before and after they removed banded tetra What must be true about the banded tetra?
A. The banded tetra is a keystone species
B. The banded tetra is a foundation species
C. The banded tetra is a parasitic relationship with these other populations
D. The banded tetra is in a mutualistic relationship with these other populations

answer; the above statement is (true);

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.