Answer:
Answers should be B. and E.
I am not 100% sure but I think it’s A sorry if I am wrong but a answer is batter then no answer lol have a good day
When two protein chains combine to form an active protein, the structural level is quaternary.
<h3>What is a quaternary structure?</h3>
The quaternary and tertiary structure of a protein is the tridimensional shape of the protein, which involves protein domains.
The quaternary protein structure refers to the different arrangements generated by different protein subunits.
The primary structure of a protein involves its amino acid sequence, whereas the second structure involves protein chains.
Learn more about quaternary structure here:
brainly.com/question/5286438
Antibodies to common microorganisms have been developed by infancy. <span>An </span>antibody<span> (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses.</span>