Immune System

Heavy chain variable regions & light chain variable region.

there are 100,000 antibodies on the surface of b-cells which are specific for particular type of antigen therefore if specific antibody recognize the particular type antigen then it attach with it and activated.

water is the oldest physical barrier. the barrier can be easily overcome with modern modes of transportation. however, inhabitants of some islands risk their lives to overcome this barrier. for example, the communist island of Cuba lies 150 km from Florida. many Cuban citizens have tried the dangerous crossing to Florida in old or leaking boats. most have been picked up the U.S coast guard, only to be returned to Cuba. many have tragically drowned in he attempt.

deserts are another physical barrier. other physical barriers include jungles, swamps, mountains, and the lack of transportation routes (roads).

barriers can also be man-made. for example the Berlin wall in Germany. it was once a heavily guarded wall splitting Germany into two - west and east Germany. it didnt let anyone escape from east Germany to west Germany. the wall was finally torn down in Germany reunited as one country.

Undoubtedly it is.

Thymus

HIV does not infect the nervous system but affects it. Since HIV suppresses the immune system, pathogens can attack the nervous system. The virus does not directly attack the nerves.

Immunology relies on both negative selection and positive selection. Negative selection, or non resultant, provides for discounting a method of treatment. Positive selection, or improvement can at times be found by elimination through negative selection.

immunoglobulins

Laryngopharyngeal reflux (LPR) refers to a relatively common disease in which gastric contents are refluxed into part of the upper GI tract and respiratory pathway. Studies have shown that the presence of LPR causes an upregulation of antibody secreting mucosal cells and stimulation of lymphoid tissue.

OOH! My specialty! YAY!

Not sure what level of detail you're looking for, so I'll go basic- let me know if you need/want more detail.

Antibodies are produced by B-cells, in response to a specific antigen. Given that, I think your question may be a little off, because it sounds as if maybe you think that an antibody will change (adapt is the term you used) to suit other antigens. In reality, once it's made, it stays as-is, in many instances for the life of the organism.

Antibodies (immunoglobulins, or Ig for short) have at least four proteins: two heavy chains and two light chains. There are 5 different types of heavy chains: Gamma, Alpha, Mu, Epsilon and Delta, which are called by the first letter of their name, and give the name of the antibody (ab for short): IgG, IgA, IgM, IgE and IgD (an easy way to remember that is to think "GAMED"). There are two light chains, Kappa and Lambda. Every B-cell produces EITHER Kappa OR Lambda, but that's irrelevant for this question (but is a key feature of lymphoma and leukemia!).

Picture the letter "Y", which is what is formed by the interaction of the two heavy chains and the two light chains- the heavy chains join together to form the bottom of the "Y", the upper arms of the "Y" consist of the other half of the heavy chain wrapped around a light chain. The bottom of the "Y" is the Fc, or Crystaline (or constant) fragment, which is specific across species (every human has the same exact Fc as does every mouse, monkey, etc). The work happens at the top of the "Y", which is the Fab (antigen binding fragment). The B-cell will customize the Fab to suit the particular antigen encountered. Once secreted from the B-cell, there's no way for the body to make further changes to the structure, so it's programmed from the very beginning, kind of like old-school CD-R (write once) versus the newer CD-RW.

Basic hand-washing may prevent many diseases from being transmitted

Antitoxins are substances that bind to toxines making them harmlles.(they losse their effect in organizm)

the answer is A for Plato

in 1492 columbus sailed the ocean blue

No they can not

Antigen is a substance that can induce the generation of antibodies, any substance that can induce immune response.

Antibody is a protective protein produced by the body in response to an antigen.

A lymphocyte is the one which has three subtype cells namely natural killer cells, T cells and B cells. The presence of antigens triggers them to be created in the bone marrow.

IgA constitutes approximately 15% of the immunoglobulins within the body. Although it is found to some degree in the blood, it is present primarily in the secretions of the respiratory and gastrointestinal tract, in saliva, colostrum.

A fever happens in order to weaken the pathogens inside the body. Once they are weakened, it is hard for them to reproduce and it is easier for the body to dispose of the pathogens. But if a fever gets too high, it breaks down protiens and can lead to permanent brain damage and damage to other parts of the body.

When babies are first born,they have only the immune defenses transferred to them by their mothers.They have not had the chance to develop antibodies of their own,

Antibodies

Treponemal antibody tests are used to rule out false-positive results on reagin tests.

a second antibody is added to the mixture. This antibody is "tagged" with a fluorescent dye so that it can be seen. The second antibody attaches to any antibodies and cells bound together

catiminatd food or water

B lymphocytes are the cells that secrete the antibodies in response to infection in body.