What is the approximate length of the DNA molecule in the nucleus of human cells?

The DNA molecule in a human cell is approximately 2 meters long. Here's how we arrive at this:

1. A human cell contains 46 chromosomes, each of which is a single, long DNA molecule.

2. Each DNA molecule - or chromosome - is about 1.7 to 8.5 cm long when uncoiled.

3. If we take an average length of 5 cm per chromosome, and multiply this by the 46 chromosomes in a cell, we get a total length of 230 cm, or 2.3 meters.

4. However, this is an overestimate because the lengths of individual chromosomes vary, and not all are as long as the average.

5. Therefore, a more accurate estimate is that the total length of DNA in a human cell is about 2 meters.

This is an astonishing fact, considering that the nucleus of a cell, where this DNA is stored, is just a few micrometers in diameter!