Which person would be the least effective host for a pathogen? •an older person
•a young athlete
•a smoker
•a sick person

How do the uv rays cause damage?   what exactly causes the skin to burn;   can you be more specific about this mechanism?   3. how do photosensitive medications increase a person's sensitivity to sunlight and therefore increase their risk of getting burned?     what kind of medications can increase photo-sensitivity, can you think of some examples?

Which of these is most likely to prevent pregnancy? a. tracking of female body temperature to identify ovulation times b. proper condom use c. male withdrawal before ejaculation d. proper spermicide use

What are possible signs and symptoms of drug addiction? check all that apply. declining physical appearance and health failing to meet family, school, or work obligations needing less and less of a drug to get the same effect using drugs when there is no health benefit failing in attempts to stop using a drug stealing to get drugs