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.
The Simple cuboidal epithelium<span> forms thyroid gland and secretes hormones is shown in the picture attached.
</span><span>Its main functions are secretion and absorption. It has an abundance of organelles to facilitate active transport frequently found in glands, such as salivary glands, the thyroid gland, and the pancreas, where its function is secretion.
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The epithelial<span> cells tend to be </span>cubical<span> in </span>form after they are inactive, however additional <span>columnar </span>after they are<span> actively secreting hormones.
The </span>epithelial<span> cells accumulate iodine from the blood and use this </span>component within the<span> synthesis of thyrog</span>lobulin<span>, </span>an oversized compound protein that<span> forms the </span>mixture<span>.</span>
IV: 4 types of nail polish
DV: brand of nail polish that lasts the longest
Control: nails
Constant: bottom coat and top coat
Experimental Group: Nail polish
Hypothesis: The types of nail polish would eventually chip away after a week .
Red blood cells. This is because they carry oxygen around the body.
"A plants vascular system is made up of specialized cells that for straw-like tubes" is the one among the following that <span>allows a plant's vascular system to work as a transport system. The correct option among all the options that are given in the question is the third option or option "C". I hope it helps you. </span>
