What immunoglobulin is primarily found in secretions and has a primary function of providing local immunity on mucosal surfaces?

It is called Immunoglobulin A or IgA.

Explanation:

Immunoglobulins are proteins or antibodies produced the lymphocytes (white blood cells) that play crucial role in immune body response. These proteins attach to invading foreign substance like bacteria and destroy them. IgA or Immunoglobulin A is a type of immunoglobulin found in secretions and play important role in immune functions of the mucosa membranes. This immunoglobulin is found in mucous secretions such as tears, saliva,sweat, colostrum, respiratory epithelium e.t.c. It is sibdivide d into two; IgA 1 and IgA 2. IgA immunoglobulin is 15% of all the antibody secreted in the body. The quantity of IgA secreted in the mucosal membranes is more than a the antibody secreted in the body.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem