Answer:
The loss of fur is a protection mechanism for the epithelium that covers us, over the years this method of protection was replaced by the protection provided by melanocytes with their melanin, therefore people who had a low presence of melanin could not survive in the evolution.
Explanation:
The presence of melanocytes and melanin in the skin is what protects it against ultraviolet radiation, over time the human being was affected by solar radiation, thus being one of the causes of bipedalism.
In those humans where melanin is defective or a small number of melanocytes are more predisposed to suffer epithelial pathologies today.
Human evolution then led to hair loss and increased epithelial tonality, causing those who could not have this phenotypic quality to be extinct or deceased.
<span>he Streptococcus pneumoniae capsule is vital for virulence and may inhibit complement activity and phagocytosis. However, there are only limited data on the mechanisms by which the capsule affects complement and the consequences for S. pneumoniae interactions with phagocytes. Using unencapsulated serotype 2 and 4 S. pneumoniae mutants, we have confirmed that the capsule has several effects on complement activity. The capsule impaired bacterial opsonization with C3b/iC3b by both the alternative and classical complement pathways and also inhibited conversion of C3b bound to the bacterial surface to iC3b. There was increased binding of the classical pathway mediators immunoglobulin G (IgG) and C-reactive protein (CRP) to unencapsulated S. pneumoniae, indicating that the capsule could inhibit classical pathway complement activity by masking antibody recognition of subcapsular antigens, as well as by inhibiting CRP binding. Cleavage of serum IgG by the enzyme IdeS reduced C3b/iC3b deposition on all of the strains, but there were still marked increases in C3b/iC3b deposition on unencapsulated TIGR4 and D39 strains compared to encapsulated strains, suggesting that the capsule inhibits both IgG-mediated and IgG-independent complement activity against S. pneumoniae. Unencapsulated strains were more susceptible to neutrophil phagocytosis after incubation in normal serum, normal serum treated with IdeS, complement-deficient serum, and complement-deficient serum treated with IdeS or in buffer alone, suggesting that the capsule inhibits phagocytosis mediated by FcÎł receptors, complement receptors, and nonopsonic receptors. Overall, these data show that the S. pneumoniae capsule affects multiple aspects of complement- and neutrophil-mediated immunity, resulting in a profound inhibition of opsonophagocytosis.</span>
No. Osmosis is the movement of a solvent through a membrane (semi-permeable) from a less concentrated solution to a more concentrated solution to the point where the two sides reach equilibrium. Isotonic solutions are solutions where the two sides of the membrane are already at equilibrium - so there is no movement of the solvent (like water) - so this is different from osmosis.
<span>If it didn't, one cell would end up with the original DNA, the other wouldn't be a functional cell, because it would lack DNA. If the DNA was split between the two cells, neither cell would have a complete copy.
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Answer:
D it has 21 atoms 7 carbon 6 oxygen 5 hydrogen 3 nitrogen
