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.
Answer:
zygote
Explanation:
gamates fuse and create zygotes
I'm not sure, but the prefix "bi" means "two" so I would say two divisions. Hope I helped! :)
