Biological Classification

How are organisms grouped, sorted, and classified?

Why?

From the time we begin to talk, we start to name things. We like to see how things are related. It is natural then, that biologists would name and organize organisms into a classifi cation system. In this activity you will learn about the major classifi cation groups and how organisms are named.

1.    According to the envelope in Model 1, who is supposed to receive the letter?

2.    Decide with your group which of the two letters in Model 1 will be more successful at reaching its destination. Justify your choice.

3.    In Addressed Envelope 1, which four letters (A–H) correspond to the most specific part of the address?

4.    In Addressed Envelope 1, which four letters (A–H) correspond to the most general part of the address?

5.    In recent years, the United States Post Office has introduced a zip code plus 4 (H). Thinking about what you’ve learned about addresses, why would this additional information be added to address labels?

Model 2 – Taxonomy

 

Envelope (Jane Doe)

Taxa

Lion

(Panthera leo)

Tiger

(Panthera tigris)

House Cat

(Felis catus)

Country

 

Kingdom

Animalia

Animalia

Animalia

State and Zip

 

 

Chordata

Chordata

Chordata

Town

 

 

Mammalia

Mammalia

Mammalia

Street name

 

 

Carnivora

Carnivora

Carnivora

House No.

 

 

Felidae

Felidae

Felidae

Last name

 

 

Panthera*

Panthera

Felis

First name

 

 

leo

tigris

catus

6.        Using the envelope outline from Model 1, classify the full address by writing the appropriate information in the “Envelope” column in Model 2.

Read This!

Carolus Linneaus (1707–1778) is known as the father of modern taxonomy. Taxonomy is the science of finding, describing, and categorizing organisms with the ultimate goal to name the species. In traditional

Linnean taxonomy the seven major taxonomic groups are (in order from least specific to most specific) Kingdom, Phylum, Class, Order, Family, Genus, and Species. Modern taxonomy categorizes the six kingdoms into three domains.

7.        Use the Linnaean taxonomic groupings to complete the third column of the table above.

8.        Which two of the three cats listed in Model 2 are most closely related? Explain your answer.

 

9.        At which taxonomic level do the two cats you identified in Question 8 separate?

 

10.    What is the most specific taxonomic grouping in which all three cats are the same?

 

11.    What is different about the way the genus and species names are written compared to the other taxa?

 

12. The genus and species names are collectively referred to as the scientific name. It is written in a form known as binomial nomenclature, a two-term Latin naming system. There are three rules for writing a scientific name using this system. Analyze the information in Model 2 to complete the rules below:

Rule 1: The scientific name is always written in ____ parts, with the genus name written __________ and the species name __________.

Rule 2: The scientific name is always written in ______________. If it is handwritten, it is written in cursive or underlined.

Rule 3: The first letter of the genus name is a ___________________ letter.

13.    This system is used all over the world. Why do you think Latin is used instead of a more modern language?

14.    Using this system, would it be possible for two different species to have the same name?

15.    In Linnaeus’s time, classification was based on the appearance of organisms. Think about the appearance of organisms such as tadpoles and frogs, sharks and dolphins, and penguins and eagles. What are the limitations of classifying organisms by only their appearance?

16.    Considering advances in science, discuss with your group what might be a more reliable way to classify organisms. List at least three additional ways besides appearance.

Model 3 – Domains and Kingdoms

Domain

Kingdom

Cell Organization

Type of Cells

Energy Source

Eukarya

Animalia

Multicellular

Eukaryotic

Heterotrophic,  ingestion

Plantae

Multicellular (most forms)

Eukaryotic

Autotrophic

Fungi

Multicellular (most forms)

Eukaryotic

Heterotrophic, absorption

Protista

Unicellular (most forms) Multicellular (some  colonial)

Eukaryotic

Autotrophic or Heterotrophic, ingestion or  absorption

Archaea

Archaebacteria

Unicellular

Prokaryotic

Autotrophic or Heterotrophic, absorption

Bacteria

Eubacteria

Unicellular

Prokaryotic

Autotrophic or Heterotrophic, absorption

17.    Look carefully at Model 3 and compare the kingdom arrangement to the domain arrangement. Which group is larger, domain or kingdom? Justify your answer and use information from the model in your explanation.

 

18.    Refer to the Domains in the chart in Model 3.

a.     How many domains are shown?

 

b.     Which domain includes eukaryotic organisms?

 

c.      Which domains include prokaryotic organisms?

 

19.    Refer to the Kingdoms in the chart in Model 3?

a.     How many kingdoms are shown?

 

b.     Which kingdoms contain eukaryotic organisms?

 

c.      Which kingdoms contain prokaryotic organisms?

 

20.    Which kingdoms contain only unicellular organisms?

 

21.    In which domain would you place the kingdom Archaebacteria?

 

22.    In Model 3, organisms are described as autotrophic or heterotrophic in the way they get nutrition. What do these terms mean?

 


 

23. As a group, discuss and complete the following table by fi lling in the boxes with the corresponding characteristics of each organism.

Organism

Cell Organization

Type of Cells

Energy Source

Kingdom

Mushrooms

 

 

 

 

 

Amoeba

 

 

 

 

 

Flower

 

 

 

 

 

Frog

 

 

 

 

 

Millipede

 

 

 

 

Sponge