Discuss the relationship between cladograms and the classification of living organisms.

classification traditionally based on morphology;
cladistics (strength) based on molecular differences/base sequences/amino acid sequences;
cladistics (weakness) is based on probability but improbable events do occur, so relationships can be wrong;
clade includes ancestral species/descendants from that species;
members of clade share set of features not found in more distant relatives;
cladogram is a tree-like diagram where nodes/branches represent the splitting of (two) new groups from a common ancestor;
different cladograms can represent same relationships in a group;
cladogram timescale not necessary;
classification based on cladograms is often same as traditional classification;
in some groups cladograms have led to revised classification;
Accept any of the above points shown in a clearly annotated diagram.

Many answers had content that did not match well with the markscheme, making this the hardest question in the exam, as very few candidates scored full marks. Often vague statements were given, not distinguishing between the fundamental differences between cladogram and traditional methods of classification. There was no clear idea about what/how/why cladograms were done, and the differences were between them and traditional classification. Many candidates believe that cladograms are the source of data, not their presentation.