Questions

Nominal money relates more to it's measure of counting - so nominal figure of what is written on bill, while "real" relates more to it's purchasing power (usually between some periods of time). For instance 100 units in nominal could buy 2 units of good in 1950 and 1 unit of good in 2005, at the same time real value of this 100 nominal units are 100 real units in 1950 and 50 real units in 2005.

Same is with GDP. In nominal it can rise due to inflation while it can stay the same or even decrease in real value.

The Great Depression was a severe worldwide economic depression that took place mostly during the 1930s, beginning in the U.S. The timing of the Great Depression varied across nations; in most countries it started in 1929 and lasted until the late-1930s. It was the longest, deepest, and most widespread depression of the 20th century. In the 21st century, the Great Depression is commonly used as an example of how far the world's economy can decline.

DNA - Deoxyribonucleic acid is a type of nucleic acid. The sugar contained in it is called Deoxyribose.