Which group is incorrectly paired with its description?
diatoms - important producers in aquatic communities
red algae - acquired plastids by secondary endosymbiosis
apicomplexans - parasites with intricate life cycles
diplomonads - protists with modified mitochondria

Red algae - acquired plastids by secondary endosymbiosis

Explanation:

Red algae are believed to have undergo a primary endosymbiosis event. Then a second endosymbiosis event created a large group known as heterokonts.  During the primary endosymbiosis event red algae acquire their plastids.

brown

explanation:

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.