IGA is secreted into the bloodstream, whereas is secreted into mucus such as gastrointestinal fluid, colostrum, saliva, tears, and sweat:

is secreted into the bloodstream, whereas is secreted into mucus such as gastrointestinal fluid, colostrum, saliva, tears, and sweat:

a. Monomeric IgM; pentameris IgM

b. Monomeric IgA; dimeric IgA

c. Monomeric IgA; dimeric IgM

d. Dimeric IgA; monomeric IgA

b. Monomeric IgA; dimeric IgA

Explanation:

IgA is a class of antibodies that are found mainly in body secretions. In sweat, tears, saliva, mucus, breast milk, and gastrointestinal secretions, IgA is secreted as a monomeric antibody. Smaller quantities of this class of antibodies are also present in blood and lymph. However, IgA is present in a dimeric form in the bloodstream. It makes up 10–15% of all antibodies in the blood. The main function of this class of antibodies is to give localized protection of mucous membranes against bacteria and viruses.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.

thinking it would be physical characteristics