Which of the test tubes shown below was most likely produced by a sprig of elodea and a snail in the dark after 12 hours of incubation?
test tube 1
test tube 2
test tube 3
test tube 4

the test tube will be most likely the one with yellowish color.

This happen because of the respiration process between the snail and Elodea. Actually, this will heavily affected by the control factors. The more elodea that exist in the incubation, the lower the amount of CO2 would be,

i think its c. amphipod

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.