In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. based on this information alone, we can conclude that sickle-cell hemoglobin exhibits

Disruption in the primary and quaternary structure.

Explanation:

The sickle cell anemia may be defined as the change in the amino acid at sixth position. Valine is present instead of glutamic acid in beta chain due to the point mutation in the nucleotide sequence.

The mutation causes the association of tetramers in the large fibers, this indicates that the quaternary structure of protein has been altered. This alteration must have occur due to the change in the amino acid sequence in the primary structure of the protein. Secondary or tertiary structure might or might not be altered in this mutation.

Thus, the correct answer is the alteration in the primary and quaternary structure.

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