1. A scientist obtained a mass of 0.0062 nanograms of DNA from a diploid human cell - Edexcel - GCSE Biology Combined Science - Question 1 - 2019 - Paper 1

To find the mass of DNA in a haploid human cell, we first recognize that a diploid human cell contains two sets of DNA. Therefore, we divide the mass of DNA obtained from the diploid cell by 2.

The calculation is as follows:

$$\text{Mass of DNA in haploid cell} = \frac{0.0062}{2}$$

Calculating this gives:

$$\frac{0.0062}{2} = 0.0031 \text{ nanograms}$$

Next, we convert nanograms to picograms since 1 nanogram = 1000 picograms:

$$0.0031 \text{ ng} \times 1000 = 3.1 \text{ picograms}$$

Thus, the mass of DNA the scientist should obtain from a haploid human cell is 3.1 picograms.