Answer:
Except alleles
Explanation:
Alleles are different versions of the same gene and that's because they have different DNA, even though it is slightly different it can make a lot of changes so that's why they have different alleles.
Allele is actually the variant form of some genes.
The best<u> example </u>for alleles we can find in the gene for blossom color in some species of flowers or plants. Only one single gene is controlling the color and we can see sometimes different versions of it. Those different versions are called Alleles.
Body parts supplied by vein or artery.
a.) Hepatic artery - liver
b.) Carotid artery - Brain, neck, and face.
c.) Thoracic aorta - Thorax
d.) Aorta - the Main artery supplies blood to down parts of the body from the heart.
e.) Cranial vena cava - Cranium
f.) Caudal vena cava - Tail.
Answer: Climate change
Explanation:
UN Climate Action Summit 2019 was organized in 2019 to discuss the domain of global climate change research. According to this dangerous impact of climate will influence the growth of new generations to come. This included various participating organizations like World Meteorological Organization, Panel on Climate Change, Earth league and global framework, UN Environment, Global carbon project and others.
The variations might help the organism to survive if there is a change in its environment
Eg heat resistant bacteria
The variation might help the organism survive predators
Eg. Green beetles blend with green leaves thus disabling crows to spot them
:)
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.
