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.
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brainly.com/question/5286438
It's B because when the surface moves the wind forces
Answer:
(A): DNA and protein
(B): The case for proteins appeared stronger until the 1940s, especially since biochemists had identified them as a class of macromolecules with great heterogeneity and function specificity, essential requirements for the hereditary material. Moreover, little was known about nucleic acids, the physical and chemical properties of which seemed far too uniform to account for the multitude of specific hereditary traits of each organism
(C): Virulent strains are pathogenic (causing disease), whereas non-virulent strains are non-pathogenic (harmless) strains.