1 pgm of DNA is about

Options

A. 174 cm long
B. 31 cm long
C. 86 cm long
D. 11 cm long

Answer

To solve the question "1 pgm of DNA is about," we need to break it down step by step:

### Step-by-Step Solution:

1. **Understanding the Unit**:
- The term "pgm" refers to "picogram."
- A picogram is a unit of mass equal to \(1 \times 10^{-12}\) grams.

2. **Converting Picograms to a More Understandable Form**:
- Since \(1 \text{ pgm} = 1 \times 10^{-12} \text{ grams}\), we recognize that this is a very small mass.

3. **Understanding DNA Packaging**:
- DNA can be packaged in two forms: linear and condensed.
- In its linear form, 1 picogram of DNA corresponds to a certain length.

4. **Calculating Length in Linear Form**:
- When DNA is in a linear form, 1 picogram of DNA is approximately 31 centimeters long. This length is derived from the average length of DNA per unit mass.

5. **Condensed Form of DNA**:
- DNA is often condensed to fit within the nucleus of a cell.
- This condensation involves the formation of nucleosomes, which allows the DNA to be compacted significantly.

6. **Final Answer**:
- Therefore, the answer to the question "1 pgm of DNA is about" is that it is approximately **31 centimeters** in length when in a linear form.