What is the second leading cause of unintentional death for teenagers? fires/burns

all-terrain vehicle crashes

drowning

falls

The herpes viruses are important enveloped dna viruses that cause disease in vertebrates and in some invertebrates such as oysters. some of the human forms are herpes simplex virus (hsv) types i and ii, causing facial and genital lesions, and the varicella zoster virus (vsv), causing chicken pox and shingles. each of these three actively infects nervous tissue. primary infections are fairly mild, but the virus is not then cleared from the host; rather, viral genomes are maintained in cells in a latent phase. the virus can later reactivate, replicate again, and infect others.in electron micrographs of hsv infection, it can be seen that the intact virus initially reacts with cell surface proteoglycans, then with specific receptors. this is later followed by viral capsids docking with nuclear pores. afterward, the capsids go from being full to being "empty." which of the following best fits these observations? a) viral capsids are needed for the cell to become infected; only the capsids enter the nucleus.b) the viral envelope is not required for infectivity, since the envelope does not enter the nucleus.c) only the genetic material of the virus is involved in the cell's infectivity, and is injected like the genome of a phage.d) the viral envelope mediates entry into the cell, the capsid mediates entry into the nuclear membrane, and the genome is all that enters the nucleus.

Which of the following best reflects what we know about how the flu virus moves between species? a) the flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected.b) a flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans.c) an influenza virus gains new sequences of dna from another virus, such as a herpesvirus; this enables it to be transmitted to a human host.d) an animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates, the virus is passed to a new species such as a bird, and the virus mutates again and can now be transmitted to humans.

Mason joined the water polo team at his school. as part of his conditioning, mason's coach requires a 25-minute run during practice. mason's heart rate reaches 125 beats per minute, but his target heart rate zone is 138—183 beats per minute. what should mason do to get the most benefit for his heart? increase the amount of time he runs increase the speed at which he runs decrease the amount of time he runs decrease the speed at which he runs