A-Level Edexcel Biology A2 Powers and Logarithms

A-Level Edexcel Biology A2 Powers and Logarithms
Pearson Edexcel International Advanced Subsidiary/Advanced Level in Biology, Issue 2, February 2021Biology XBI11/YBI11

Review A-Level Edexcel Biology powers, exponentials and logarithms through the available data-table calculation using logarithmic or exponential relationships.

How this is tested

  • use a logarithmic or exponential equation to complete missing values in a biological data table

Question 7(b)(i)

Gel electrophoresis is used to separate DNA fragments of different lengths.
The rate at which the DNA fragments move through the gel depends on several factors including:
- molecular size of the DNA fragment
- shape of the DNA fragment
- concentration of the gel.

Fragments of double-stranded DNA move through the gel at a relative rate ( Mr\mathrm{M}_{\mathrm{r}} ) that is inversely proportional to the log of their molecular weight (MW).

Complete the table using the equation:

Mr=1log⁡10MWM_{r}=\frac{1}{\log _{10} M W}
Table for Question 7(b)(i) — Edexcel A-Level Biology A2