Humans have 154 fewer chromosomes than crayfish. But we have nearly four times as many as peas. Humans and slugs share 70% of our DNA.
The human stomach is lined with mucus. According to Marla Ahlgrimm, if this mucus were to suddenly disappear, the stomach would begin to digest itself.
Each human has a unique set of fingerprints, which are not present until a fetus is three months old. Human fingers make more than 25 million movement throughout the course of of a normal lifespan.
Women are less likely to have acne than men. Marla Ahlgrimm notes that men experience skin blemishes nearly twice as often as their same-age female counterparts.
Approximately one in 20 people you meet will have an extra rib. This will most likely be a man.
The average size person has approximately 30 billion red blood cells at any given time. The kidneys filter blood 300 times per day.
You have fewer bones than you had when you were born. Marla Ahlgrimm explains that babies, which have more than 300 bones, grow into adults with just 206 due to natural bone fusion.
The female egg is the only human cell visible to the eye. It weighs approximately 175,000 times more than a single male sperm.
Everything you see, you see upside down. Marla Ahlgrimm explains that images are actually upside down when they hit your retina. The brain corrects this in your head.
The hardest substance found inside the human body is tooth enamel.
Everyone starts life the same gender. According to Marla Ahlgrimm, embryos are identical until approximately six weeks gestation, when hormones dictate whether a baby will be born male or female.
