The slightest change in pH can destroy the substance or organism. The pH of a cell's interior helps regulate the cell's chemical reactions. For example, the pH of blood is 7.4, if blood falls to 6.8 or lower or 8.2 or higher, it results in death.
The skin is made up of three layers, each with its own important parts. The layer on the outside is called the epidermis
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:
Abiotic components of an ecosystem are water, air, light, soil, and temperature.
Now think about how the availability of these things will affect what could live in a specific area.
Consider a desert ecosystem. Deserts are arid, receiving little rain (water) and have extreme temperatures (both cold and hot). Because of these conditions only certain plants and animals can live here. These plants and animals have adaptations that are specific to the environment. If you were to put an organism that does not belong in there, they would most likely die out.
Tidbit for you. The Atacama desert is one of the driest places in the world, located specifically in Chile. At one point, this place did not receive any rain for 500 years! Still plants and animals are able to live in this area. When it finally did rain, the sudden downpour caused a radical change in this ecosystem. You would think at first rain would be good, but no. Because the changes the rain brought was too drastic, it caused a devastating effect on the organisms that lived there because they were not adapted to rain.
