Why are some protists heterotrophic?

Heterotrophic protista. These Protista are also known as Protozoa, which means “first animals”; in fact, the term does not mean that all protozoa are the ancestors of the animals, but refers to the fact that they ingest food, which is typical of animals. read more

Most organisms are heterotrophs because they cannot produce their own food. This group of organisms includes all types of fungi and animals. Some bacteria are also classified as heterotrophs. read more

Photosynthetic protists such as the various types of algae contain plastids. These organelles serve as the site of photosynthesis (the process of harvesting sunlight to produce nutrients in the form of carbohydrates). The plastids of some protists are similar to those of plants. read more

Some protists are autotrophic and are able to make organic carbon-containing nutrients like glucose. Other protists are heterotrophic, and can't make their own carbon containing nutrients. Heterotrophic protists have to obtain carbon-containing nutrients by ingesting them -- by 'eating' other organisms or decaying organic matter in the environment. read more