Why are gamma rays not affected by a magnet as they pass over it? gamma rays are composed of only energy. gamma rays do not have enough mass to be affected. gamma rays do not have the right electrical charge to be affected. gamma rays move too fast for anything to affect their pathway.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.