In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: Immunoglobulin isotype change affects: 
 Options:  <0> The constant regions of the heavy chains. <1> The constant regions of the light chains. <2> The totality of heavy chains. <3> The entire immunoglobulin molecule. <4> The hypervariable regions of the heavy chains.
biology

Question: The following may occur in multimeric form associated with the J chain: 
 Options:  <0> IgA and IgG. <1> IgD and IgM, <2> IdE and IgD. <3> IgA and IgD. <4> IgA and IgM.
biology

Question: A homogeneous reaction between ideal gases that has reached chemical equilibrium can evolve (ie, move towards the formation of more reactants or products) in the following way if this equilibrium is altered: 
 Options:  <0> If the temperature is increased at constant pressure, it will go to where more moles will be produced. <1> If the pressure is increased to constant temperature it will go to where the volume is higher. <2> If an inert gas is added it will go to where this gas is consumed. <3> If a gas that participates in the reaction is added, it will go to where more gas is produced. <4> If the temperature is decreased, it will go to where the reaction is exothermic.

chemistry