Close examination of an organ reveals a lining of several layers of cells. The layers do not contain any blood vessels and one surface of the cells is open to the internal cavity of the organ. This tissue is probably

Epithelium

Explanation:

Epithelium are tissue massage found mostly in the skin and serve as protective covering for the internal and external parts of the body.

A major characteristic of the epithelium is that its layers do not contain any blood vessels such as the artery or vein. The surface of the cells is also usually open to the internal cavity of the organ.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

hi, natural selection of the peppered moth during the industrial revolution in 19th-century england is an example of an outlier in the study of evolution. during this time, pollution from factories filled the forests, coating trees in a layer of soot—turning white trees black

mark as brainlest

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