Classifying living things
| English | Chinese | Pinyin |
|---|---|---|
| classify | 分类 | fēn lèi |
| species | 物种 | wù zhǒng |
| fertile | 可育的 | kě yù de |
| binomial system | 双名法 | shuāng míng fǎ |
| genus | 属 | shǔ |
| kingdom | 界 | jiè |
| dichotomous key | 二歧检索表 | èr qí jiǎn suǒ biǎo |
Bringing order to millions
- Scientists have named over a million kinds of living thing — and there are millions more.
- To make sense of them, we classify 分类: sort them into groups by shared features.
Classification rank lab
Place examples at the right level in the biological hierarchy.
A species is a group of organisms that can:
Members of a species breed to give fertile offspring.
Members of the same species breed to produce ______ offspring.
Fertile offspring can themselves reproduce.
Species 物种 and naming
- A species is a group of organisms that can breed together to make fertile 可育的 offspring.
- Each species has a two-word Latin name (the binomial system 双名法): genus 属 then species, e.g. Homo sapiens.
Living organisms are sorted into five kingdoms 界 by their main features
In the binomial system, the first word of the name is the:
The binomial is genus then species, e.g. Homo sapiens.
Put these classification groups in order from largest to smallest.
Kingdom → phylum → class → order → family → genus → species.
The classification hierarchy
- Organisms are sorted into ever-smaller groups: kingdom → phylum → class → order → family → genus → species.
- The more features two organisms share, the more groups they share — and the more closely related they are.
A fungus: the fly agaric, a mushroom
A dichotomous key identifies an organism using:
Each step offers two choices, narrowing down the organism.
Using a dichotomous key 二歧检索表
- A dichotomous key identifies an organism through a series of paired (either/or) questions.
- Each answer leads to the next question, until the organism is named.
Worked example. The binomial name Panthera leo (lion) shares its genus (Panthera) with Panthera tigris (tiger) — telling you at a glance that lions and tigers are closely related.
You've got it
- a species can breed to make fertile offspring; named by the binomial system (genus + species)
- classification hierarchy: kingdom → phylum → class → order → family → genus → species
- a dichotomous key identifies organisms through paired questions