Mammograms are x-rays done to women that check for breast cancer. For women who are not at risk, regular mammogram tests can start at age 50. Or, to be cautious, a women can get a mammogram earlier, around the age 40 and be given every 2 years. Having these types of checks on a regular basis is the most effective way to detect breast cancer early.
A pap smear is a medical test done to women to check for problems in cervix. Pap smears do not need to be given unless doctors detect something is wrong. Once a girl turns 21, she should begin getting pap smears regularly (every 3 years) to monitor health.
A testicular exam is an easy way for guys to check for unusual bumps or lumps in area. Regular testicular exams should be started between the ages 15 to 36 and should be given every month.
How to Preform a Testicular Self-Examination: http://kidshealth.org/en/teens/tse.html#catsexual
A prostate exam is an exam to check for cancer for men. Generally, the test is given at the ages between 40-70 and should not be given after age 70. This test is a good tool to find cancer early and should be given when needed.
Prostate Cancer Screening: http://www.mayoclinic.org/diseases-conditions/prostate-cancer/in-depth/prostate-cancer/art-20048087