Why are nations more likely to have cultural boundaries within them than nation-states?

A cultural boundary is a non-physical boundary that differentiates different ethnicities  and cultures based on their race, language, cultural traditions and beliefs.

A Nation-state is a type of state that is conformed only by one ethnicity. This is why Nation-states are less likely to have cultural boundaries than Nations. There would not be a lot of cultural boundaries in a society that is conformed only by the same ethnicity. Citizens of a Nation-State share the same language, beliefs and traditions. While in a Nation it is easy to find citizens that belong to different ethnicities, therefore they have different religions, languages or cultural traditions.

the anterior pituitary gland produces the following hormones and releases them into the bloodstream: psychotropic hormone, which stimulates the adrenal glands to secrete steroid hormones, principally cortisol. growth hormone, which regulates growth, metabolism and body       hope i

the constitution gives congress the power to regulate commerce "among" the several states.