Natural selection leads to increases in the mean fitness of populations and so will reduce the frequency of disease-associated alleles, but other evolutionary processes, such as mutation and gene flow, may introduce or increase the frequency of these deleterious alleles.
The correct order is -
Vessel spasm; plug formation; coagulation
A vascular spasm or vessel spasm is a sudden tightening of a blood vessel. The platelet plug or also called hemostatic plug formation is an accumulation of platelets formed in response to blood vessel wall injury. And coagulation or clotting is the process in which blood changes from a liquid to a gel thus forming a blood clot.
epithelial layers contain no blood vessels, so they must receive nourishment via diffusion of substances from the underlying connective tissue , through the basement membrane.
Explanation:
d.incinerators are to reducing
Maintaining acidity- <span>In case the pH in the environment drops a lot (becomes very acidic), there is a flux of H ions from the cell's cytoplasm into the cell's vacuole thereby increasing acidity to required level and thus maintaining the </span><span>specific pH </span><span>in the cells internal environment as well.
Turgidity- </span><span>Vacuoles regulate the turgidity by regulating the amount of water inside the cell. </span>
cell has excessive water:<span> vacuole absorbs the water and then diffuses it out of the cell.</span>
cell lacks water<span>: water from the vacuole gets passed back into the cell thereby maintaining turgidity.
And here's a video </span>https://youtu.be/3tqjITi8S8s