This is a type III hypersensitivity reaction mediated by immune complex deposits. Immune complexes are antigen-antibody (commonly IgG) complexes that are soluble and prone to deposition in multiple organs. Once immune complexes are deposited in an organ, neutrophils and macrophages will then attack the organ causing organ damage and eventually failure. Type III hypersensitivity reactions are characteristic in SLE and other autoimmune diseases such as rheumatoid arthritis, etc.
Other types are type I hypersensitivity which are mediated by mast cells and histamine with the involvement of IgE and this commonly happens in allergic reactions. Type II hypersensitivity is cytotoxic hypersensitivity wherein antibodies directly attack organs (not forming immune complexes). Type IV hypersensitivity (or cell-mediated toxicity) involves T-lymphocytes. This is a delayed type of hypersensitivity exemplified by reactions from <em>M. tuberculosis</em> bacilli in tuberculous disease.
The Cell Will Shrink
Hypertonic solutions have less water ( and more solute such as salt or sugar ) than a cell. Seawater is hypertonic. If you place an animal or a plant cell in a hypertonic solution, the cell shrinks, because it loses water ( water moves from a higher concentration inside the cell to a lower concentration outside ).
Answer:
The short answers are Yes, it's random, and Yes, it "waits" for some time.
Different tRNA's just float around in the cytoplasma, and diffuse more or less freely around. When one happens to bump into the ribosome, at the right spot, right orientation, and of course which has an anticodon matching the codon in frame of the mRNA being translated, it gets bound and takes part in the synthesis step that adds the amino acid to the protein that is being synthesized.
The concentration of the various species of tRNA is such that translation occurs in a steady fashion, but there is always some waiting involved for a suitable tRNA to be bound. In that waiting time, the ribosome and mRNA stay aligned - that's because the energy that is required to move the to the next position is delivered as part of the same chemical reaction that transfers the amino acid from the tRNA to the protein that is being synthesized.
I'm not entirely sure what happens if there is significant depletion of a particular species of tRNA, but I think it's likely the ribosome / RNA complex can disassemble spontaneously. But spontaneous disassembly can't be something that occurs very easily after translation was initiated, since we would end up with lots of partial proteins which I expect would be lethal very soon.
(Can't know for sure though, but it would be very hard to set up an experiment to measure just what will happen and even if you got a measurement it would be hard to figure out how it applies to normal, living cells. I can't imagine tRNA depletion occurs in normal, healthy living cells.)
<span>Positive Rh factor represents the presence of the rhesus protein on the blood cells.</span> <span>Rh factor or Rhesus factor is used to describe the presence of antigen Rh (D) in the blood. A person who is, for example, AB Positive (AB+) has the A and B antigens and the Rh(D) antigen, whereas someone who is AB Negative (ab-) lacks the Rh(D) antigen. Antibodies to Rh antigens can be involved in hemolytic transfusion reactions and they increase the risk of Hemolytic disease of the fetus and newborn, so it is important for mother and the baby to have the same Rh factor.</span>
Microevolution is a change in the frequency of gene variants, alleles, in a population, typically occurring over a relatively short time period.
Population genetics is the field of biology that studies allele frequencies in populations and how they change over time if this doesn’t (I hope this is right if It don’t know what will)
