Classification, domains and evolutionary trees
| English | 中文 | Pinyin |
|---|---|---|
| binomial name/baɪˈnəʊmɪəl neɪm/ | 双名 | shuāng míng |
| domain/dəˈmeɪn/ | 域 | yù |
What would explain this observation?
- Two organisms can look similar without being the closest relatives. New evidence from cells and chemistry can revise their classification.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Linnaeus classified organisms using structure and characteristics. The traditional hierarchy is kingdom, phylum, class, order, family, genus and species. Binomial names 双名 use genus and species: for example, Homo sapiens. The genus begins with a capital and the species name with lower case; the complete scientific name is normally italicised.
- binomial name: A scientific name consisting of genus and species; domain 域: A broad classification group in the three-domain system.
Which pair forms a binomial name?
Improved microscopy revealed internal structures and biochemical analysis provided further relationship evidence. Woese’s three-domain system separates archaea, bacteria and eukaryota; eukaryota includes protists, fungi, plants and animals. The specification describes archaea using older primitive-bacteria wording and extreme habitats; treat archaea as a separate domain rather than all bacteria or a claim that every archaeon lives in an extreme habitat.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Improved microscopy revealed internal structures and biochemical analysis provided further relationship evidence. Woese’s three-domain system separates archaea, bacteria and eukaryota; eukaryota includes protists, fungi, plants and animals. The specification describes archaea using older primitive-bacteria wording and extreme habitats; treat archaea as a separate domain rather than all bacteria or a claim that every archaeon lives in an extreme habitat.
- Use a supplied classification table to identify the most specific shared group. On an evolutionary tree, find the most recent shared branch point to compare relationships. Living-organism classification data and fossil evidence inform these trees. Rotating branches around a node does not change the relationships, and tip order alone is not an evolutionary sequence.
Which two habits make the investigation or model in this case more defensible?
Use a supplied classification table to identify the most specific shared group. On an evolutionary tree, find the most recent shared branch point to compare relationships. Living-organism classification data and fossil evidence inform these trees. Rotating branches around a node does not change the relationships, and tip order alone is not an evolutionary sequence.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: a supplied group contains 12 plants, 8 fungi and 10 animals, all assigned to eukaryota. Total = 30; fungi comprise 8/30×100 = 26.7% to one decimal place. This sample percentage does not measure the global proportions of domains or kingdoms.
A supplied eukaryote sample has 15 plants, 9 fungi and 6 animals. Find the fungal percentage. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A supplied eukaryote sample has 15 plants, 9 fungi and 6 animals. Find the fungal percentage.
The result is 30 %. Known: a supplied group contains 12 plants, 8 fungi and 10 animals, all assigned to eukaryota. Total = 30; fungi comprise 8/30×100 = 26.7% to one decimal place. This sample percentage does not measure the global proportions of domains or kingdoms.
Check the conclusion and its limits
- A binomial name has two parts, not all seven hierarchy ranks. Archaea and bacteria are separate domains in this system. An evolutionary tree does not say that a living species at one tip must be the direct ancestor of a living species at another tip.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
All archaea belong to the bacterial domain in the three-domain system. This claim is false: A binomial name has two parts, not all seven hierarchy ranks. Archaea and bacteria are separate domains in this system. An evolutionary tree does not say that a living species at one tip must be the direct ancestor of a living species at another tip.
Classification, domains and evolutionary trees: Improved microscopy revealed internal structures and biochemical analysis provided further relationship evidence. Woese’s three-domain system separates archaea, bacteria and eukaryota; eukaryota includes protists, fungi, plants and animals. The specification describes archaea using older primitive-bacteria wording and extreme habitats; treat archaea as a separate domain rather than all bacteria or a claim that every archaeon lives in an extreme habitat.
All archaea belong to the bacterial domain in the three-domain system.
A binomial name has two parts, not all seven hierarchy ranks. Archaea and bacteria are separate domains in this system. An evolutionary tree does not say that a living species at one tip must be the direct ancestor of a living species at another tip.
A scientific name consisting of genus and species: write the technical term.
binomial name means A scientific name consisting of genus and species.