In order to improve the condition of your muscular system, you could participate in aerobic activity at least
a. 3 minutes 5 times a week
b. 10 minutes 4 times a week
c. 30 minutes 3 times a week
d. 50 minutes 3 times a week

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.

How does stress affect the digestive system? o a. reduces ability to break down foods b. reduces acid production to slow digestion o c. increases desire for fruits and vegetables o d. increases ability to break down food submit

Send sperm live for about 48 hours after ejaculation and ovum for only 24 hours after ovulation intercourse can occur after ovulation for fertilization to occur