Transcript Classification Introduction

Classification Introduction
S7L1a:Develop a dichotomous key
S7L1b: Classify organisms based on
physical characteristics
• Evolution has lead to great diversity of life,
therefore scientist must have a way to
organize all of the diversity, but how?
Question to think about…
• If you go to the grocery store to buy some
bread, where do you look? Explain how a
grocery store is set up.
What is classification?
• The grouping similar items together
How does classification relate to life
science?
• Today, scientist group all organisms based on
similarities in both external and internal
features.
• They use classification to determine an
organism’s phylogeny
What is phylogeny?
• The evolutionary history of an organism, or
how it has changed over time.
Similar to a grocery store….
• You have the bread aisle (all the bread in the store)
• Then different types of bread (hotdog buns, hamburger
buns, sandwich bread)
• Then a variety of the same types of bread (sandwich
bread: white, wheat, crust-less, etc)
• Then specific names for the bread (Publix brand, Sara
Lee, etc)
The modern classification systems has
seven levels.
• Kingdom (Animal, Plant, Fungi, Protist,
Eubacteria, Archaebacteria) LARGEST GROUP
• Phylum
• Class
• Order
• Family
• Genus
• Species (an organism’s specific name) SMALLEST
GROUP
How do you determine species specific
names?
• Binomial nomenclature  the two-word naming
system used to name the various species.
• First word of the two-word system identifies the
genus of the organism (group of similar species)
• The second name tells you something about the
specific organism
What are tools for identifying
organism’s scientific name?
• Dichotomous keys
– Detailed list of identifying characteristics that
includes scientific names
– Arranged in steps with two descriptive statements
at each step
– You always start with step one!
– As you answer one question, the key sends you to
another step, and you continue the steps until you
identify the organism's scientific name.
Dichotomous key example
• http://www.hort.uconn.edu/plants/keys/trees
/treekey01.html
• http://www.mdsg.umd.edu/programs/educati
on/interactive_lessons/key/student1.htm
Summary
• Create an acronym to help you remember
seven categories of classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Example:
Kings
Play
Chess
On
Funny
Green
Squares