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: A study is being conducted in a health center to determine the effect of exposure to tobacco smoke in children of smoking parents. For this purpose, a group of healthy children between 3 and 7 years old whose parents are smokers is selected and at the same time an equal number of children whose parents are non-smokers are selected in the same center. A year later, the appearance of respiratory diseases during that year will be investigated in both groups. Indicate the correct answer: 
 Options:  <1> The study design is a prospective cohort. <2> The study design is cases and controls. <3> The study design follows a qualitative methodology. <4> The study is experimental. <5> The type of design used is efficient to study rare diseases.
1

Question: Transcription factors: 
 Options:  <1> They bind to chromatin by interaction with histone H2A. <2> They bind to RNA and regulate the start of transcription. <3> They join the DNA. <4> They are organized into nucleosomes. <5> They regulate DNA methylation.

3