Which type of skin receptor is a nonencapsulated (free) nerve ending that is triggered by extreme temperature changes, pinch, or release of chemicals from damaged tissue, acids or chemicals such as capsaicin in hot chilis

What major structure can be used to tell apart the embryos of acoelomates pseudocoelomates and coelomates?

The chemical form of energy that is useable by the cell to do work

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?