<span>The primary psychosocial milestone of childhood is the positive development of self-concept. This usually begins at 18 months, but continues throughout childhood. Self-concept is simply how one views oneself and one's abilities.</span>
The renal corpuscle consists
of a capillary bed called the glomerulus and a capsule of epithelial cells.
The renal corpuscle is composed
of two structures, the glomerulus and the Bowman's capsule. The glomerulus is a
small tuft of capillaries containing two cell types. <span>It is also characterized
as a cluster of capillaries around the end of a kidney tubule, where waste
products are filtered from the blood. Other
surfaces that separate body cavities from the outside environment are lined by
simple squamous, columnar, or pseudostratified epithelial cells.The gastrointestinal tract, the insides of the lungs, and the
reproductive and urinary tracts where other epithelial cells line up make up
the exocrine and endocrine glands.</span>
The answer is mitochondrion, it is called as "the power of cell"
Natural selection is the right answer hope this helps.
