Lymphocytes are activated by antigen in the

  1. Lymphocytes are activated by antigen in the

    A.blood stream
    B.bone marrow
    C.liver
    D.lymph nodes

IgE provides

A.immunity against some parasites
B.complement killings of the cells and phagocytosis	
C.secretions in the body
D.all of the above

Which of the following is correct?

A.	Membranes form boundaries around the cell and distinct subcellular components
B.	Membranes act as selectively permeable barrier
C.	Membranes contain varying amount of lipid and protein and some contain small amount of carbohydrates	
D.	All of the above