Quick questions on Linnaean classification and dichotomous keys: QCE Biology Unit 3

The hierarchy has eight ranks from broadest to most specific. A simple mnemonic is "Do Kings Play Chess On Fine Green Sand".

Every species has a two-part Latinised name.

Linnaeus grouped organisms by morphology. Modern classification uses molecular data (DNA, RNA, protein sequences) to build phylogenetic trees that reflect evolutionary descent. As a result, some traditional groupings have been revised. Examples relevant to Australian fauna:

1. Use observable, stable features. Leaf shape, body symmetry, number of legs, presence of feathers. Avoid behaviour, geographic location and seasonal traits. 2.

Specimens: a beetle, a spider, a millipede and an earthworm.

Bacteria, Archaea and Eukarya. Bacteria and Archaea are both prokaryotic but differ in cell wall chemistry, membrane lipids and ribosomal RNA. Eukarya contains protists, fungi, plants and animals.

Forgetting italics, capitalising the species epithet, or writing only the species epithet without the genus all lose marks. Always write Genus species in italics.

Order and class are commonly swapped. Use the mnemonic, or recognise that order is more specific than class but less specific than family.

"Body is medium sized" is not a clean split. Quantify it or rephrase.

It is updated as new molecular evidence becomes available. Marks are awarded for using current names.