Stem cells are the body's raw materials â cells from which all other cells with specialized functions are generated. Under the right conditions in the body or a laboratory, stem cells divide to form more cells called daughter cells. These daughter cells either become new stem cells (self-renewal) or become specialized cells (differentiation) with a more specific function, such as blood cells, brain cells, heart muscle or bone. No other cell in the body has the natural ability to generate new cell types.
(December 2011) (Learn how and when to remove this template message) The hangman's knot or hangman's noose (also known as a collar during the Elizabethan era) is a well-known knot most often associated with its use in hanging a person.
Tying General Knots. 1  1. Tie an overhand knot. Overhand knots are probably the easiest, and first, knot that people learn to tie. 2  2. Tie a bowline knot. This knot, also called a bowline hitch, makes a fixed loop at the end of a rope or string. 3  3. Tie a square knot. Square knots are also called reef knots.  4. Tie sheet bend knots.