processes

Question 1

phagocytosis

Answer 1

-opsonin binds to the antigen on the plasma membrane
-a Neutrophil binds to the opsonin attached to the pathogen’s antigen
-The pathogen is engulfed by endocytosis, forming a phagosome (a vesicle that forms around the engulfed pathogen)
-Lysosomes fuse to the phagosome and release, lytic enzymes into it
-After digestion by lysozymes, the harmless products can be absorbed into the cell

Question 2

skin repair

Answer 2

-abrasion/laceration damages the skin
-Clot forms, and dries out to form a scab
-scab shrinks as it dries drawing sides of a cut together
-temporary seal formed under which the skin is repaired
(The deposition of collagen under the scabs initiates the skin repair process )
-Stem cells divide by mitosis, migrate to the edge of the cut and differentiate to form new skin
-New blood vessels grow to supply oxygen and nutrients to the new tissues
-Tissues contract to help draw edges of the cut so repair can be completed
-As the new skin is completed, the scab will be released