The correct answer is B. Thymus gland: enables immature lymphocytes to mature into T cells
D) Stem cells are usually harvested from embryos.
<u>Answer:</u>
<em>There are innermost serious membranes that cover the heart is Parietal Pericardium.</em>
<u>Explanation:</u>
Heart is <em>covered by pericardium</em> in two sides, inner and outer sides. The inner membrane is parietal pericardium and the outer one is visceral pericardium. Pericardium is made up of <em>fiber tissues</em> that strongly protect the heart from all around.
The<em> main function of pericardium</em> is to protect the heart from any injuries and prevent the infections. The serious pericardium helps in<em> lubricating the heart. </em>
