How do you understand that attachment of ear lobes are inherited?

Answer 1

Whether or not an ear lobe is attached at its base or not depends on whether or not that person's parents had attached earlobes or not. If both parents have attached earlobes, then their children will also have attached earlobes. If both parents have detached earlobes, then their children will also have detached earlobes. But if one parent has detached earlobes, while the other has attached earlobes, their child's earlobes may be detached, attached, or only slightly attached.

This is because each parent provides part of the DNA (deoxyribonucleic acid) molecules that exist at the center of almost every human cell. Since the cells of the body don't "know" anything, they just follow the "instructions" that DNA provides them by building themselves according to how the DNA molecule says they should be built.

How this actually works is a complicated chemical process that would be better answered in a separate question, but you don't need to know how it works, only that the result is this - children get some instructions for how to build their body from their mother, and some from their father. If the instructions agree, then the cells that make up the ear will grow a definitely attached or detached earlobe. If the instructions in the child's DNA disagree, then you might get a mix, or the cells might end up paying attention only to one set of instructions or another.