Questions

A spanning tree is a tree associated with a network. All the nodes of the graph appear on the tree once. A minimum spanning tree is a spanning tree organized so that the total edge weight between nodes is minimized

Leukocyte, commonly known as a white blood cell (WBC), is a major component in protecting the body against invading microorganisms and body cells with mutated DNA, and they clean up debris. 

B Lymphocyte also called as B-Cells or plasma cells produces the antibodies or immunoglobulins that bind to specific foreign or abnormal components of plasma membranes. This is also referred to as humoral (body fluid) immunity.