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Author Question: The fetus begins to develop male sex organs if: the SRY gene on the Y chromosome commands the sex ... (Read 229 times) |
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.
Cutaneous mucormycosis is a rare fungal infection that has been fatal in at least 29% of cases, and in as many as 83% of cases, depending on the patient's health prior to infection. It has occurred often after natural disasters such as tornados, and early treatment is essential.
The senior population grows every year. Seniors older than 65 years of age now comprise more than 13% of the total population. However, women outlive men. In the 85-and-over age group, there are only 45 men to every 100 women.