Species diversity - Number of species

Western Ghats have greater amphibian species diversity than the Eastern Ghats. 

The overall richness of species is concentrated in equatorial regions and tends to decrease as one moves from equatorial to polar regions.India has 390 different mammals (rated eight highest in the world); 1,232 species of birds (eighth in the world); 456 species of reptiles (fifth in the world) and 45,000 plant species, of which most are angiosperms, (fifteenth in the world)

TLS Online TPP Program

#Id: 7478

#Unit 4. Cell Communication and Cell Signaling

IgM antibodies are produced first in a humoral immune response and tend to be of low affinity.

IgM molecules form pentamers that are stabilized by a single J-chain molecule.

This higher avidity of the pentamer compensates for the low affinity

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#Id: 7479

#Unit 4. Cell Communication and Cell Signaling

IgG efficiently opsonizes pathogens for engulfment by phagocytes and activates the complement system. The affinity of the individual antigen binding sites for their antigen is therefore critical for the effectiveness of these antibodies, and most of the B cells expressing these classes have been selected in the germinal centers for their increased affinity for antigen after somatic hyper mutation.

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#Id: 7480

#Unit 4. Cell Communication and Cell Signaling

IgA is the principal class in secretions, the most important being those from the epithelia lining the intestinal and respiratory tracts.

Dimeric IgA operates mainly on epithelial surfaces.

This monomeric IgA is predominantly of the subclass IgA1; the ratio of IgA1 to IgA2 in the blood is 10:1.

IgA antibodies produced by plasma cells in the gut are dimeric and predominantly of subclass IgA2; the ratio of IgA2 to IgA1 in the gut is 3:2.

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#Id: 7481

#Unit 4. Cell Communication and Cell Signaling

IgE 

Present only at very low levels in blood or extracellular fluid but is bound avidly by receptors on mast cells.Antigen binding to this cell-associated IgE triggers mast cells to release powerful chemical mediators that induce reactions such as coughing, sneezing, and vomiting.

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#Id: 7482

#Unit 4. Cell Communication and Cell Signaling

IgD

B cell antigen receptor and may participate in B cell maturation.Exact function is still unclear, IgD may be involved in humoral immune responses by regulating B cell selection and homeostasis.

TLS Online TPP Program

#Id: 7483

#Unit 4. Cell Communication and Cell Signaling

Function of antibody