Question

What are the three ways in which bacteria obtain food?

Answer 1

Photosynthesis, chemosynthesis and symbiosis

Explanation:

1. The first way bacteria can obtain food is via photosynthesis. Like plants, many bacteria contain chloroplasts or blue-green pigments, which means they can photosynthesize and thus create their own food by absorbing sunlight. Because these bacteria can create their own energy, they are classified as autotrophs.

2. The second way bacteria can obtain food is through chemosynthesis, of which there are two types: Autotrophic chemosynthesis, and heterotrophic chemosynthesis.

Chemotropic autotrophs are bacteria which gain energy by breaking down inorganic molecules and chemical compunds in their environment, such as sulfides or ammonia, and are important for cycling nitrogen through the ecosystem.

Chemotrophic heterotrophs, or decomposers, are bacteria which gain energy by breaking down organic substances. This includes waste products, dead organic matter and other organic compounds. These bacteria are vital for making sure certain elements and minerals cycle through the ecosystem so that life can continue.

1. The third way bacteria can obtain food is through symbiosis , of which there are three types: Mutualism, Commensalism and Parasitism.

Mutualism is when two species exist in a relationship which is beneficial to both. An example of this is the relationship between humans and gut bacteria. The gut bacteria ensures that we are able to digest food efficently, and in return they get a constant of material with which they can ingest.

Commensalism is when two species exist in a relationship where one species benefits and the other species isn't affected. An example of this is the relationship between humans and skin bacteria. These bacteria eat at our dead skin cells and skin oils, obtaining energy, while we are unaffected.
http://www.encyclopedia.com/science/news-wires-white-papers-and-books/human-commensal-and-mutual-organisms

Parasitism is when two species exist in a relationship where one species benefits at the expense of the other species. An example of this is the relationship between cholera and humans. Cholera infects humans and starts to reproduce, using us as a host, while humans develop diarrhea, vomiting, and potential death if not treated.
http://sciencing.com/types-bacteria-parasites-8470244.html

https://www.ck12.org/book/CK-12-Life-Science-Concepts-For-Middle-School/section/5.2/