Question

Are all protists heterotrophs?

Answer 1

Protista is unicellular, prokaryotic microorganisms that show the link with both prokaryotes and eukaryotes. Protista shows a different mode of nutrition. In the case of Protista bearing chlorophyll, they show photosynthesis and if it does not bear chlorophyll it does not show photosynthesis and will depend on other organisms to do their nutrition.

Complete answer:
Protista shows different types of mode of nutrition like photosynthetic, holozoic, saprobic, parasitic and mixotrophic. Therefore all Protists are not heterotrophs.
Protista show similarities or link with other kingdoms, therefore it has different modes of nutrition.
-Photosynthetic protists consist of chlorophyll and it shows photosynthesis by consumption of carbon dioxide and water.
-Holozoic protists capture and ingest food the same as animals.
-Saprobic protists obtain food from dead and decay organic matter and it converts organic matter into simpler products with the help of enzymes and then the food gets absorbed through the body surface.
-Parasitic protists obtain food from other organisms and it also causes the death of host organisms.
- Mixotrophic protists are both holophytic and saprophytic, therefore these organisms get all types of nutrition.
In protista, the breakdown of food takes place in the both aerobic and anaerobic form and digestion of food takes place with the help of lysosomes and the undigested food gets expelled out from the body.

Note:
The main difference in characteristics of protists, fungi and lower plants can be observed by their number, morphology, size and insertion of flagella. Flagella are the organelles that are present from the ancient organisms therefore flagella are considered an ancient organelle.