2. (a) A scientist obtained a mass of 0.0062 nanograms of DNA from a diploid human cell - Edexcel - GCSE Biology - Question 2 - 2019 - Paper 1

To determine the mass of DNA from a haploid human cell, we need to know that human cells are diploid, meaning they contain two sets of chromosomes. Given the mass of DNA from a diploid cell as 0.0062 nanograms, we can calculate the haploid mass as follows:

1. First, we divide the mass of DNA from the diploid cell by 2: $ext{Mass from haploid cell} = \frac{0.0062 ext{ ng}}{2} = 0.0031 ext{ ng}$

2. Next, we convert nanograms to picograms using the conversion factor: $1 ext{ ng} = 1000 ext{ pg}$ $0.0031 ext{ ng} = 0.0031 \times 1000 = 3.1 ext{ pg}$

Therefore, the answer is: 3.1 picograms.