A-Level Biology AQA 7402

Genetic diversity within, or between species, can be made by comparing:

• the frequency of measurable or observable characteristics
• the base sequence of DNA
• the base sequence of mRNA
• the amino acid sequence of the proteins encoded by DNA and mRNA.

Students should be able to:

• interpret data relating to similarities and differences in the base sequences of DNA and in the amino acid sequences of proteins to suggest relationships between different organisms within a species and between species
• appreciate that gene technology has caused a change in the methods of investigating genetic diversity; inferring DNA differences from measurable or observable characteristics has been replaced by direct investigation of DNA sequences.

Knowledge of gene technologies will not be tested.

Quantitative investigations of variation within a species involve:

• collecting data from random samples
• calculating a mean value of the collected data and the standard deviation of that mean
• interpreting mean values and their standard deviations.

Students will not be required to calculate standard deviations in written papers.