5. Living with the 2 species of paramecium there are photosynthetic protists too called euglena. How do you know they too must be present in the paramecium's environment?

they both go up but then go back down. they both end lower than they started. lastly, they both are competitive/the second on.

explanation:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.