They have had their genes changed to contain a special characteristic, like resistance to certain insects.

VOA: special.2010.11.09

another thing that you'd find if you looked inside the axon terminals of any of these pre-synaptic membranes, you'd find lots of vesicles or some membrane bound compartments that contain special chemicals called neurotransmitters.

如果你仔细观察,突触前膜的轴突末梢内部,你会发现很多小泡,即膜包被的结构,包含有称为神经递质的特殊化合物

耶鲁公开课 - 生物医学工程探索课程节选

They're red because they contain a special protein called hemoglobin which is very concentrated inside the cell.

红细胞的红色源于,其内部一种叫做血红蛋白的特殊蛋白质,血红蛋白在细胞内的浓度很高

耶鲁公开课 - 生物医学工程探索课程节选