Question

the h in the infographic refers to the hemagglutinin gene. there are at least 15 different alleles (versions) of this gene. the n is a different gene called neuraminidase. what is different between the flu outbreaks of 1957 and 1968?
o the neuraminidase genes have different sequences.
o the neuraminidase genes are in different locations.
o the hemagglutinin genes are in different locations.
o the hemagglutinin genes have different sequences.

Explanation:

The infographic shows different flu strains (1957 H2N2 and 1968 H3N2). The "H" refers to hemagglutinin. Since the "H" numbers (2 vs. 3) are different, it implies the hemagglutinin genes (which determine the "H" type) have different sequences. The location of genes is not indicated as a factor here, and the neuraminidase ("N") is the same (N2) in 1957 and 1968 (if we assume the strain naming - 1957 is H2N2, 1968 is H3N2, so N is N2 for both, so neuraminidase is not the differentiating factor).

Answer:

The hemagglutinin genes have different sequences.