Answer:
Explanation:
There are some signs and symptoms that a person may exhibit if they are in pain that can clue you in:
Facial grimacing or a frown.
Writhing or constant shifting in bed.
Moaning, groaning, or whimpering.
Restlessness and agitation.
Appearing uneasy and tense, perhaps drawing their legs up or kicking.
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
The two main components of the extracellular matrix are Elastin and Collagen.
The extracellular matrix is an intricate macromolecular network that is found in the extracellular space. The matrix is composed of polysaccharides and very diverse proteins, locally secreted and assembled forming a complex network that surrounds the cells. The matrix is highly developed in connective tissue and its derivatives. The extracellular matrix is formed mainly by proteins, glycosaminoglycans,proteoglycans and glycoproteins, organized in diverse networks that constitute the different tissues. <em>The most abundant proteins are collagen and elastin.</em>
Collagen is a family of very abundant proteins in the body of animals. Collagen molecules can represent 25 to 30 % of all body proteins. Its main mission in the tissues is to form a framework that supports the tissues and that resists the forces of mechanical tension.
The elastin molecules are very close to each other through links between the regions rich in the amino acid lysine. It is an abundant protein in may extracellular matrices and appears as a component of the so called elastic fibers, which are onsoluble aggregates of proteins.
