The wall of the heart<span> consists of three </span>layers<span>: the epicardium (external </span>layer<span>), the myocardium (middle </span>layer<span>) and the endocardium (inner </span>layer<span>). The epicardium is the thin, transparent </span>outer layer<span> of the wall and is composed of delicate connective tissue.
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Answer:
Biogeochemical cycle is one of the several natural cycles, in which conserved matter moves through biotic and abiotic parts of a ecosystem. In biology, conserved matter refers to the finite amount of matter, in the forms of atoms, that present within the earth.
Explanation: It is true that the chemical is one of the natural cycles within earth