<span>The heart contains four chambers: upper left atria, upper right atria, lower left ventricle and the lower right ventricle. Oftentimes, the right atria and right ventricle are together referred to as the "right heart" and the left atria and left ventricle are referred to as the "left heart", however there are still four separate chambers.</span>
Answer:
commensalism
an association between organisms in which one benefits and the other derives nor harm
<span>your answer ..is sea lilies </span>
