Collagen protein fibers are located in many parts of the body, including the muscles, tendons, ligaments, and bones. Collagen and another protein called elastin are often found together.
Immediately, the pathogen has been recognized:
Macrophages acts as the first line of defence by engulfing pathogens identified by antigens which will now present the antibody shape to a helper T cell.
The Helper T cells produce a signal to plasma and Memory B cells to yield antibodies that attach to the antigens. The cytotoxic cells that leads to cell death are activated by the helper T cells.
Antibodies helps to immobilize pathogen for macrophage to feed on.
if the pathogen comes back a 2nd time the memory cells helps in quick and efficient recovery by producing the specific B and T cells for the antigen.
The sponges draw water carrying food particles into the spongocoel using the beating of flagella in the choanocytes. ... Compare the structural differences between Porifera and Cnidaria. Poriferans do not possess true tissues, whereas cnidarians do have tissues.
Answer:
D. Valve.
Explanation:
These allow blood to flow through without flowing back.
Valance electrones are located in the very last shell of the perticular atom. And hence, the shell is known as valance shell of the atom.
