|
|
Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.
Elderly adults are living longer, and causes of death are shifting. At the same time, autopsy rates are at or near their lowest in history.
Only 12 hours after an egg cell is fertilized by a sperm cell, the egg cell starts to divide. As it continues to divide, it moves along the fallopian tube toward the uterus at about 1 inch per day.
Drying your hands with a paper towel will reduce the bacterial count on your hands by 45–60%.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.