Did you know?
Vaccines prevent between 2.5 and 4 million deaths every year.
Did you know?
A headache when you wake up in the morning is indicative of sinusitis. Other symptoms of sinusitis can include fever, weakness, tiredness, a cough that may be more severe at night, and a runny nose or nasal congestion.
Did you know?
Immunoglobulin injections may give short-term protection against, or reduce severity of certain diseases. They help people who have an inherited problem making their own antibodies, or those who are having certain types of cancer treatments.
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Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
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IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.
The frequency of competition according to the number of species involved.
Competition among Paramecium species.
Comparison of the radius of fruits produced by native and introduced species of Sapindaceae
Human physiology
Human eye anatomy
Leonardo da Vinci, Study of Human Proportion: The Vitruvian Man.