Question

Several groups of protists have variable modes of nutrition: Some species are photoautotrophs, whereas close relatives are heterotrophs. Such diversity even exists within a single species in some cases. Evidence suggests that this pattern is a result of the __________.

Answer 1

Answer:

The endosymbiotic theory

Explanation:

Protists are the multicellular organisms which possess characteristics of both the prokaryotes and eukaryotes.

The protist can derive nutrition by either heterotrophic mode or photoautotrophic mode. This variation could exist within the same genus and same species.

This variation could be explained with the endosymbiotic origin of the organisms as some species could engulf the photosynthetic bacteria whereas some could have engulfed the chemosynthetic bacteria.

This can be observed in the green and red algae which depend on a different mode of nutrition belonging to the same group.

Thus, the endosymbiotic theory is correct.