The heart is an example of which level of organization within an organism? cell
organ
tissue
оо
organ system

Ineed a chemical reaction takes place in which erlergy is released. arrange the reaction's characteristics in order from start to finis lower energy of reactants higher energy of products higher energy of reactants transition state sd lower energy of products

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

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?