In an experiment, a scientist compares the effect of adding acid rain to
samples taken from two different lakes. the scientist observes that ten drops
of acid rain added to water taken from lake minnetonka in southern
minnesota does not change the ph from 7.5, but ten drops of acid rain added
to water taken from upper kintla lake in glacier national park causes the ph
to change from 7.5 to 5.2.
which conclusion is supported by these observations?
o
a. both lake minnetonka and upper kintla lake contain a buffer,
o
b. upper kintla lake contains a buffer, but lake minnetonka does
not
o
c. neither lake minnetonka nor upper kintla lake contains a buffer
o
d. lake minnetonka contains a buffer, but upper kintla lake does
not

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.

cell/ tissue/ organ/ organ system/ body

the answer is