The H1N1 and H3N2 viruses both cause the flu, an infectious disease characterized by respiratory symptoms, fever, and body aches. Each year, a flu vaccine that contains H1N1 and H3N2 antigens is developed. An individual who receives the vaccine makes antibodies directed against these antigens.

The flu vaccine is typically about 60% effective against H1N1 flu viruses, but only 30% effective against H3N2 viruses. What is the most likely reason why the flu vaccine is less effective against the H3N2 flu viruses than the H1N1 flu viruses?

A. Infection with the H1N1 virus does not involve an immune system response.
B. Infection with the H3N2 virus does not involve an immune system response.
C. The H3N2 flu viruses mutate more rapidly than the H1N1 flu viruses.
D. The H1N1 flu viruses mutate more rapidly than the H3N2 flu viruses.

This is one form of rna that transports a specific amino acid to a ribosome during protein synthesis.

If the coding part of an mrna molecule is 1800 nucleotides (bases) in length, this molecule will contain codons and code for a polypeptide that is amino acids long.

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.