<prompt> Zwitterions are examples ofAnionsCationsNeutral ionsNone of the above  <response>: Molecules that contain an equal number of positively and negatively charged groups bear no net charge. These ionized neutral species are termed zwitterions.Zwitterions are one example of an isoelectric species the form of a molecule that has an equal number of positive and negative charges and thus is electrically neutral.Ref: Harpers illustrated biochemistry. 30th edition page no: 20 