[填空题]
The cladogram below shows three possifle a3ke,w5 1uf-uje )fw **jible evolutionars.3ixb 96 bezty origins of the platypus (Platypus X, Y, and Z), an egg-laib3 bx9t.e6s zying mammal with webbed feet. The italicised taxa are extinct.
1.1.State the taxa most closely related to marsupials.
are most closely related to marsupials. They are both members of Theria.
1.2.Based on the taxa shown in the cladogram, deduce one reason for the difficulty in identifying the true divergence of the platypus.
2.1.The cladogram shown is based on morphological traits. Describe one other type of evidence that can be used to deduce evolutionary relationships.
2.2.Suggest one type of morphological evidence that could be used to provide support for Platypus Z over Platypus X as the origin of the platypus.
3.Taxonomists classify organisms according to their evolutionary origins using a hierarchical classification system.
Outline the principal taxonomic ranks in the modern classification system.
