Tay-Sachs disease is caused by a defective gene on chromosome 15. When both parents carry the defective Tay-Sachs gene, a child has a 25% chance of developing the disease. The child must receive two copies of the defective gene -- one from each parent -- in order to become sick.
Enacted by law in 2013, the newest symbols of North Carolina are the state art medium, clay; the state fossil, the Megalodon teeth; the state frog, the Pine Barrens tree frog; the state marsupial, the Virginia opossum; and the state salamander, the Marbled salamander.
Numerically controlled oscillator. A numerically controlled oscillator (NCO) is a digital signal generator which creates a synchronous (i.e. clocked), discrete-time, discrete-valued representation of a waveform, usually sinusoidal. NCOs are often used in conjunction with a digital-to-analog converter (DAC) at the output to create a direct digital synthesizer (DDS).