evolutionary) relationships between species

Question 1

Haemoglobins are chemically similar molecules found in many different species.

Differences in the primary structure of haemoglobin molecules can provide evidence of phylogenetic (evolutionary) relationships between species.

Explain how.

Answer 1

Mutations change base / nucleotide (sequence);

Reject if mutation in amino acid

2. (Causing) change in amino acid sequence;
3. Mutations build up over time;
4. More mutations / more differences (in amino acid / base / nucleotide sequence / primary structure) between distantly related species;

OR

Few(er) mutations / differences (in amino acid / base / nucleotide sequence / primary structure) in closely related species;

5. Distantly related species have earlier common ancestor;

OR

Closely related species have recent common ancestor;