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?
Your heart beats over 36 million times a year.
Did you know?
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Did you know?
About 100 new prescription or over-the-counter drugs come into the U.S. market every year.
Did you know?
Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.
Different types of stems
The Land Ordinance of 1785 called for surveying and dividing the Western Territories into square mil