Which of the following STDs can be transmitted by a seemingly healthy person? AIDS
herpes
chlamydia
gonorrhea
syphills
all of the above

What is the main structural difference between enveloped and nonenveloped viruses? a) enveloped viruses have their genetic material enclosed by a layer made only of protein. b) nonenveloped viruses have only a phospholipid membrane, while enveloped viruses have two membranes, the other one being a protein capsid. c) enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane. d) both types of viruses have a capsid and phospholipid membrane; but in the nonenveloped virus the genetic material is between these two membranes, while in the enveloped virus the genetic material is inside both membranes.

Which of the following mental illness does not begin during adolescence? a. post-traumatic stress disorder b. obsessive-compulsive disorder. c. schizophrenia. d. addictions

In 2009, 40% of all bicyclist fatalities occurred when the bicyclist, the driver, or both vehicle operators were