AP BIOLOGY

Detailed explanation-1: -What are the types of isomerism? Two main forms of isomerism are structural or constitutional isomerism, in which bonds between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the relative positions of the atoms differ.

Detailed explanation-2: -There are three types of Structural isomerism existing namely chain isomerism, position isomerism and functional group isomerism.

Detailed explanation-3: -Structural isomers are those compounds that differ in their connectivity between the atoms that constitute that compound. Stereoisomers are compounds with the same exact molecular formula and connectivity but they differ in the arrangement of atoms in three-dimensional space.

Detailed explanation-4: -So there are four structural and stereoisomers. So the correct answer is option ‘D’. Note : One of the types of structural isomerism is chain isomerism in which the components of these isomers are branched in different structures.