Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
The correct answer is option A, that is, blood.
Cell theory in biology refers to the universally acknowledged scientific theory that living species are constructed of cells, that is, they are the basic fundamental and structural unit of all species, and that all the cells arises from the pre-existing cells. The theory is credited to Schwann and Schleiden. The three postulates of the theory are:
1. All living species comprises of one or more cells.
2. Cell originate from the pre-existing cells.
3. The cells is the fundamental unit of organization and composition in organisms.
Is it a question or ... no ?
Answer:
Yes.
Explanation:
Parallel circuit are those types of circuits in which break in one branch does not prevent the flow of current in the circuit and the current can still flow through another branch because there are more ways through which the current moves to other sources while on the other hand, series circuit refers to those circuits in which break in one branch can prevent the current flow in the circuit and the other sources can't receive current due to broken of the connection.
