AP BIOLOGY

Detailed explanation-1: -In the example of corals, the host animal is a multicellular cnidarian, and the endosymbiont is a unicellular alga called a dinoflagellate. The host animal serves as a protected environment, providing the alga with a constant supply of nutrients in the form of nitrogen, phosphorus, and sulfur.

Detailed explanation-2: -The small cells (now called endosymbionts) benefited from the relationship by getting a safe home and nutrients. The large cells (now called hosts) benefited by getting some of the organic molecules or energy released by the endosymbionts.

Detailed explanation-3: -The endosymbiotic theory posits that some eukaryotic cell organelles, such as mitochondria and plastids, evolved from free-living prokaryotes. Available data indicate that the mitochondrial endosymbiosis initiated the evolution of the eukaryotic cell, as suggested by Margulis.

Detailed explanation-4: -7.2 Primary and Secondary Endosymbiosis. A symbiotic relationship where one organism lives inside the other is known as endosymbiosis. Primary endosymbiosis refers to the original internalization of prokaryotes by an ancestral eukaryotic cell, resulting in the formation of the mitochondria and chloroplasts.