In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Question: With regard to pyrogens and biotechnological medicines, it is possible to say: 
 Options:  <1> They have no tendency to aggregate or form large units with high molecular weight. <2> Ion exchange chromatography procedures (using their positive charge) can reduce endotoxin levels. <3> Ion exchange chromatography procedures (using their negative charge) can reduce endotoxin levels. <4> Ion exchange chromatography procedures (regardless of their charge) can reduce endotoxin levels. <5> They are unstable under standard autoclaving conditions.
3

Question: In the receptor-mediated endocytosis intervenes: 
 Options:  <1> Only the clathrin. <2> Only the adaptin. <3> Adaptine and clathrin. <4> Chaperones <5> Only the proteins of the membrane.
3

Question: The chemical reactions of the splicing process of the introns during the maturation of the pre-mRNAs consists of: 
 Options:  <1> An oxidation-reduction reaction. <2> A transesterification reaction. <3> Two sequential transesterification reactions. <4> Three sequential transesterification reactions. <5> A transesterification reaction followed by another oxidation reaction.

3