Biology - Mr.Willets
Taxonomy
In order to keep track of all of the different kinds of living things, there must be a system that organizes them into groups. Such a system was first devised by the Greek philosopher, Aristotle, over 2000 years ago.
His system was used until the 1700's. It was changed then because, by that time, his system was too simple for the wide variety of newly discovered organisms.
A Swedish naturalist, Carolus Linnaeus, devised a new system to classify organisms and it is his system (somewhat modified over time) that we use today. The science of classifying organisms into groups is called taxonomy.
The largest groups in our taxonomic system are the Kingdoms. There are 6 of them: Archaebacteria, Eubacteria, Protista, Fungi, Plant and Animal. Each of these kingdoms is divided into smaller groups called phyla (sing-phylum). Each phylum is divided into groups called classes and so on. Eventually, the groups become small enough that they contain a single kind of organism- a species.
The groups in order from largest to smallest are: Kingdom, Phylum, Class, Order, Family, Genus, Species. (Note- Botanists use the word 'division' instead of phylum but we can ignore that) When we name an organism, we use the name of its genus group followed by the name of its species. The genus name is capitalized but the species name is not. Both names are either underlined or put into italics.
Sometimes, the genus name is used without the species name (never the other way around). If a culture jar is labelled "Drosophila", I know it contains some kind of fruit fly. If it is labelled "Drosophila melanogaster", I know exactly which kind of fruit fly it contains. Often, the genus name is abbreviated using only its first letter. For example, instead of writing Drosophila melanogaster over and over we might, to save time and space, write D. melanogaster .
The word genus means "general" and the word species means "specific". When you indicate the genus of an organism, you are saying what kind of organism it is in general. When you give the species name also, you are indicating specifically what it is. (By the way, the Genus Edition of Trivial Pursuit has general knowledge questions rather than specific topics)
Since each organism is officially given 2 names (genus and species), this is called binomial nomenclature ("two-name" " naming system")
We use a similar two-name system for people. The last name gives us an idea of what family the person is from and the first name tells us exactly which member of that family he or she is. Which of our twonames is similar to the genus name? Which is similar to the species name?
When organisms are put into the various groups, it is done by using a wide variety of characteristics:
physical, biochemical, genetic, embryological etc. There are often arguments about how organisms should be classified and taxonomists are always changing their minds. However, for two organisms to be considered the same species, they must be able to reproduce with each other and produce normal offspring. There are occasional exceptions to this general rule.
Questions-
1) What do we call the system we use to classify living things? ______________________________
2) What is the largest taxonomic group called ______________________ How many of these are
there? __________
3) Of the 6 kingdoms, which one's name does not tell you what type of organisms are in it? _____________
4) Each kingdom is divided into smaller groups called __________________
5) Each phylum is divided into smaller groups called ___________________
6) Each class is divided into smaller groups called __________________
7) Each order is divided into smaller groups called _________________
8) Each family is divided into smaller groups called __________________
9) Each genus is divided into smaller groups called ______________
10) The species is a group that contains ________________________________________
11) What are the 7 basic taxonomic groups in order from largest to
smallest? _____________________
____________________________________________________________________________
12) When an organism is given a scientific name, we use the name of which two groups that it is part of?
_____________ and _____________ Which one is capitalized? _______________ Both are either written in _________________ or are ______________________
13) The word "genus" means _____________________ This is because the genus name tells you
in _____________________ what kind of organism it is.
14) What does the word "species" mean? _______________ The species name tells you ________________________ what kind of organism it is.
15) Which of your two names gives the more general information about you (first or last)? ____________
Which indicates specifically who, in the general group, you are? _________________
When you write your name, which part comes first, the more specific or the more general name? ___________________ When your name is written in a phone book or any place where we want to keep track of you, which name comes first- the more specific or the more general? ___________________
In the scientific name of an organism, which name comes first, the more specific or the more general? _____________________
16) If two organisms are considered to be the same species, this means that they can _________________
with each other and produce ____________________________