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:
See explanation below.
Explanation:
Starfish, also known as sea stars, are marine organisms that belong to the Class Asteroidea. They are considered invertebrates because they lack a vertebral column. Moreover, most starfish species have five arms but some species can have up to 15!
Here are some characteristics that differentiate starfish from other organisms and make them so unique:
- Possession of tube feet.
- Most species have pedicellaria, claw-shaped structures with movable jaws.
- Radial symmetry
- They can possess from 5 to 15 arms.
- Do not possess brain.
- They can regenerate parts of their body.
Answer:
Ofcourse it does
Explanation:
Imagine one person have flu and he or she goes to met someone who is healthy but when they talk other infected person's flu goes to other healthy person and that new infected person goes to another and they go to another and thats how it seperate. But we have solution for this the first infected person need to wear mask so that his or her flu don't pass out to anothers.
Answer:
Uses of genetic engineering include:
increasing plant food production
improving medical treatment
Explanation:
Genetic engineering can be described as a technique in which the genome of an organism is manipulated for the benefit of humankind. The processes of genetic engineering involved the manipulation of the plants and animals DNA so that they will be able to produce more better characteristics. Also, drugs such as vaccines can be produced in animals by the techniques of genetic engineering.
Answer:
an English scientist Robert hooke
