Did you know?
More than 50% of American adults have oral herpes, which is commonly known as "cold sores" or "fever blisters." The herpes virus can be active on the skin surface without showing any signs or causing any symptoms.
Did you know?
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
Did you know?
More than one-third of adult Americans are obese. Diseases that kill the largest number of people annually, such as heart disease, cancer, diabetes, stroke, and hypertension, can be attributed to diet.
Did you know?
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Did you know?
Acetaminophen (Tylenol) in overdose can seriously damage the liver. It should never be taken by people who use alcohol heavily; it can result in severe liver damage and even a condition requiring a liver transplant.
Structure of a typical animal cell
X-ray showing typical joint changes associated with osteoarthritis.
Poor ventilation of oceans
What’s the Secret of Math Success?
The genome of a typical retrovirus is shown at the top of the diagram