Question

1. a positive result on bea is indicated by: a. red zone b. yellow slant biol 2120 differential and selective media homework c. black precipitate in media d. green sheen

Explanation:

In the context of BEA (Bile - Esculin Agar), a positive result is indicated by the hydrolysis of esculin in the presence of bile salts. This leads to the formation of a black precipitate in the media due to the reaction of esculetin with ferric ions in the agar.

Answer:

C. Black precipitate in media