How much DNA in a cell?

Question

Each (nucleated) human cell is supposed have several feet of DNA - what sort of area would this cover? (per cell)

Answer 1

A human has about 3 billion base pairs' worth of DNA that ends up duplicated in the sets of chromosomes. The double-helix of DNA is about 3.4 nanometers long for every ten base pairs. Simple multiplication yields a result of 2.04 meters of DNA in each cell... or about 80 inches' worth. That assumes you could line it all up end-to-end (something it wouldn't really want to do!).

If you want to get more precise than that, the double helix of DNA is pretty uniformly 2 nanometers across. Viewed from above, it would cover a total area 2.04 m long and 2 nm wide, for an area of about 0.004 square millimeters (assuming you could get it to lie flat). It's total volume would by about 6 x10^-18 cubic meters (that's a billionth of a billionth)... let's just say it's still really, really small, even though it's long.

Answer 2

The DNA present in a single cell, if it were unravelled, would be about two metres long. In an adult human being, if the number of cells is round about 10^13, then the total length of DNA would extend from the earth to the sun 100 times. Yet this DNA is tightly packed inside the chromosomes of each cell.

Answer 3

A DNA molecule is smaller than a cell... Which are you asking about? A human cell or the DNA molecules within the nucleous of the cell?

Answer 4

How about the area inside the nucleus...because that's where it's stored. Even when broken down the base pairs still fit inside the nucleus, which is approximately 20% of the total area of the cell.

Answer 5

here's a good source:

http://hypertextbook.com/facts/1998/StevenChen.shtml

It wuold cover a very small total area though, as these lengths are premised on being a single molecule thick - more like a very thin thread.

Answer 6

Manchester Utd football ground?