Answer:
Blood clothing is an example of positive feedback.
This type of feedback mechanism is useful to the body because it multiplies the factor that intervenes in clotting accelerating the process. 
If a toxin affects the molecules that signal for platelets the feedback will not be effective enough to produce clotting and the body will keep bleeding.
Explanation:
 Blood clotting is an example of positive feedback due to the fact that when the vascular endothelium is damaged  platelets will go to this area and activate themselves once they are in contact with the collagen fibers of the damaged structure. When the platelets are activated they will release the contents that is stored in their granules. One of the contents is a Gq-linked protein receptor cascade,  that will increase the concentration of calcium in the platelets. Calcium activates protein kinase C, which, in turn, activates phospholipase A2 (PLA2). PLA2  will modifies  an  integrin membrane  increasing its affinity to bind fibrinogen. The activated platelets change their  shape , and the fibrinogen cross-links with the integrin membrane aiding  in  the aggregation of adjacent platelets. After this the coagulation cascade takes place. there are two pathways the extrinsic  and the extrinsic one.
The extrinsic pathway will be activated due to tissular factor released  by the platelets and the intrinsic pathway will be activated due to endothelial collagen. The final product of both pathways is factor x.
Factor x will transform prothrombin into thrombin will activate the conversion of fibrinogen into fibrin. Thrombin will form a net of fibrin that will the clot.
A cascade reaction is useful because every component of the cascade are related making a quick reaction once that one of then is activated and can activate other or more factors.
If a toxin affects the molecules that signals for platelets, platelets will not go to the damaged area and in consequence there will not be thrombin and fibrin to form the clot together with platelets.
 
        
             
        
        
        
Answer:
Dna i think im not sure if it is right?
Explanation:
 
        
                    
             
        
        
        
NO, they should not.
Erythrocytes, leucocytes, and proteins (albumin)
are not small enough to pass through the capillaries of the
glomerulus unless there is damage to the glomerulus. However, glucose does pass through into the glomerular filtrate. Nonetheless, glucose is fully reabsorbed back in the proximal
convoluted tubule (unless you have severe diabetes).
 
        
             
        
        
        
Answer:
Evidence of metamorphism can be indicated by <u>flat, horizontal</u> layers within the rock.
Explanation:
Metamorphic rocks refer to rocks that are modified with heat or pressure, which change their physical and chemical properties. The main reason behind this modification is the rearrangement of the mineral crystals, which occurs due to their response to the previously-mentioned properties of heat and pressure. 
There could be different types of evidence of metamorphism. However, the main evidence can be indicated by the presence of <u>flat, horizontal</u> layers within the rock, also known as foliation, a process that occurs when the pressure squeezes the minerals, leading to a flat, horizontal layer. Then, scientists could analyze the composition of these layers to identify minerals or even fossils within it.
 
        
             
        
        
        
Answer:
Plate Boundaries
Explanation:
Puerto Rico might be on a plate boundary. When two plates slide against each other (also called a transform boundary) they can cause a earthquake to happen on the surface.