Classification

Biology

The study of life.

What characteristics do you look for to determine if something is living or non-living?

WHY DO WE CLASSIFY ORGANISMS?

• We classify organisms in order to study the diversity of life.

• Biologist use a classification system to name the organism and group them into a logical manner.

In order to make their job easier, scientists classify living things into groups, based on how they are the same, and how they are different.

What is the name of the animals to the right?

• What is the name of the animals to the right?

A) Cats

B) Gatos

C) Katzen

D) Felis Catus

What is the name of the animals to the right?

• What is the name of the animals to the right?

A)CatsB)GatosC)KatzenD)Felis Catus

All of these names are correct, but D is the universal name of these animals.

What is Classification?

Classification arranges objects, ideas, or information

into groups by finding common

traits or characteristics.

The Science of Classification

Taxonomy: is the branch of biology concerned with the grouping and naming

of organisms.

Scientist who classify ororganize organisms (animals and plants)

are called taxonomists. Taxonomists study taxonomy.

The History of Organization

Aristotle 384-322 BCInterested in biological classification.

Patterns in nature.

Carl Linnaeus1707-1778 ACE

Father ofBiological

Classification!

Aristotle

• Developed the first system of classification.

• He classified all living things into plants and animals.

• Animals were grouped depending on where they lived. (On land, in air or in water)

• Later scientist became convinced that his system did not work because of organisms living in multiple habitats.

Carolus Linnaeus• Developed the system of

classification that is still used today.

• He selected physical characteristics that led to classification based on close relationships of organisms.

• He used characteristics such as bats having hair and feeding their young milk to classify the organisms.

• The system devised by Linnaeus gives each organism two names called Binomial Nomenclature.

• Every organism is given a two-part scientific name.

1. Genus name is always placed first, is capitalized and underlined. Homo

2. The second word describes the organism in scientific terms. It is always lowercase and underlined. sapiens

Human binomial name = Homo sapiens– Together they are the species name.

• Without the genus name, the specific epithet is meaningless

Common name: Robin

• Erithacus rubicula

• Turdus migratorus

Common name: Black and Polar Bear

Ursus americanus

Ursus maritimus

There are six basic characteristics of life. All living things posses the following traits.

1. Show an orderly structure,or organization, of tiny units called cells.

2. Reproduce to make more living things. 3. Change during their lives through growth and

development.4. Adjust to their surroundings.5. Obtain and use energy to run the processes of

life.6. Pass on traits to their offspring.

2 types of Reproduction

1. ASEXUAL (binary fission) a single parent passes exact copies of it’s DNA to it’s offspring. Occurs in bacteria and single celled organisms such as the amoeba.

The single-celled amoeba demonstratesa simple method of asexual reproduction; it divides in half by a process called fission, producing two smaller daughter cells. Aftera period of feeding and growth, these two daughter cells will themselves divide in half.

2 types of Reproduction

2. SEXUAL - organisms having genetic characteristics derived from two parents are produced.

Male and female reproductive cells (gametes) unite to form a single cell, known as a zygote, which later undergoes successive divisions to form a new organism.

Adjust = HOMEOSTASIS

• Organisms respond to their external environment and then process the internal demands accordingly.

• The maintenance of stable internal conditions in spite of changes in the external environment.

Example: temperature of a human is always around 98.6 regardless of the temperature outside.

New Discoveries

Questions

How can you answer these questions?

Why is Taxonomy Important?

Unknown species discovered.

New fossil Uncovered.

Why Do We Classify Living Things?

There are an estimated 10 million to 30 million species on earth.

Classification determines methods for

organizing the diversity of life on earth by

providing a framework of logic and order so

that relationships among living things and

once living things can be seen easily.

TAXONOMY

• Science of classifying organisms.

• Scientists identify new organisms and determine how to place them into an existing classification scheme.

• Scientists who study the grouping and naming of organisms are known as taxonomists.

Groups are also arranged in hierarchical order.

Hierarchical Classification

Memorize the Classification System Order

• Taxonomic categories– Kingdom (big) King– Phylum Philip– Class Came– Order Over– Family For– Genus Grape– Species (small) Soda

SPECIES

• A GROUP OF SIMILAR LOOKING ORGANISMS THAT SHARE SIMILAR CHARACTERISTICS AND CAN INTERBREED WITH ONE ANOTHER TO PRODUCE FERTILE OFFSPRING.

horse + donkey = mule (non-fertile offspring)

species + species = non-species

The Six Kingdoms

1. Archaebacteria Collectively 1 and 2

2. Eubacteria are known as Monera.

3. Protista

4. Fungi

5. Plantae

6. Animalia

I. Archaebacteria• Ancient bacteria

• Prokaryotes (do not have a true nucleus), single celled organisms.

• Live in extreme environments such as salt lakes, swamps and VERY deep within the ocean.

• Cell walls without peptidoglycan

• Subdivided into 3 groups based on their habitat --- methanogens, thermoacidophiles, & extreme halophiles

Halophiles (like salt) Thermophiles (like heat)

II. Eubacteria

• True bacteria

• Found in practically every environment on Earth.

Eubacteria

Come in 3 basic shapes --- cocci (spheres), bacilli (rod shaped), spirilla (corkscrew shape)

• Most are heterotrophic (can’t make their own food)

• Cell walls made of peptidoglycan• Can be aerobic (require oxygen) or anaerobic

(don’t need oxygen) • Can be identified by Gram staining (gram gram

positivepositive or gram negativegram negative)  

Eubacteria

• Staphylococcus aureus 

• Bacillus anthracis

• E. coli

III. Protista• First eukaryotic kingdom (true nucleus)

• Contains multicellular and unicellular species.

• Heterotrophic – that ingest small food particles & digest it inside food vacuoles containing digestive enzymes

• Classified by the way they move (cilia, flagella, pseudopodia...)

• Motile – able to move.Examples include Ameobas, Parameciums and kelp.

Amoeba

Euglena

Rotifer

Algae

Peter Parks/Oxford Scientific Films

Amoeba Engulfing a Paramecium

An amoeba, a single-celled organism lacking internal organs, is shown approaching a much smaller paramecium, which it begins to engulf with large outflowings of its cytoplasm, called pseudopodia. Once the paramecium is completely engulfed, a primitive digestive cavity, called a vacuole, forms around it. In the vacuole, acids break the paramecium down into chemicals that the amoeba can diffuse back into its cytoplasm for nourishment.

IV. Fungi• Eukaryotes• Unicellular or multicellular• Do not contain chlorophyll (non-photosynthetic• Store food energy as glycogen• Most are saprobes – live on other dead organisms.

Decomposers – obtain energy by breaking down organic material that they absorb from the environment.

• Nonmotile -cannot move• Lack true roots, stems, & leaves • Mostly Cell walls contain chitin – tough outer

covering found on insects. (a complex polysaccharide)

Examples of Fungi

Mold

Yeast

Ringworm

Mushrooms

V. Plantae

• Eukaryotes• Multicellular• Nonmotile• Contain chlorophyll inside of chloroplasts• Cell wall made of cellulose • Plants (also called autotrophs or producers) trap

energy from the sun by photosynthesis & store it in organic compounds

• All plants that reproduce sexually

VI. Animalia• Eukaryotic• Heterotrophic

(take in food & internally digest it) • Multicellular• Most are motile• Cells contain a nucleus and

membrane bound organelles• Cells lack cell walls• Show levels of organization including cell,

tissue, organ, & system • Cells are specialized for particular functions

Animalia

• 99% of the organisms in Kingdom Animalia are invertebrates – meaning they lack a backbone.

• Organisms that have a backbone are called verterbrates.

1. Which Kingdom do I belong to?

2. Which Kingdom do I belong to?

3. Which Kingdom do I belong to?

4. Which Kingdom do I belong to?

5. Which Kingdom do I belong to?

6. Which Kingdom do I belong to?

7. Which Kingdom do I belong to?

8. Which Kingdom do I belong to?

9. Which Kingdom do I belong to?

10. Which Kingdom do I belong to?

Animalia

• The Kingdom Animalia is divided into 6 phyla:

1. Sponges and Cnidarians

2. Mollusks

3. Worms

4. Arthropods

5. Echinoderms

6. Verterbrates

1. Sponges and Cnidarians

- The only animals that

do not have tissues.

- Mostly marine.

- Ex. Jellyfish, corals

2. Mollusks

• Have something called a coulomb (sac-like structure) that encloses their internal organs.

• Most have a hard external skeleton (shell).

• Ex. Snails, oysters, clams, octopuses

2. Mollusks

3. Worms

• Cylinder shaped bodies.

• Live on both land and water.

4. Arthropods

• Most diverse of all animals.

• Have an external skeleton.

• Have jointed appendages, such as antennae and jaws.

• High rate of reproduction.

• 2/3 of all animals.

4. Arthropods

5. Echinoderms

• Ability to regenerate a lost limb.

• Ex. Sea stars, sea urchins

6. Verterbrates

• Internal skeleton made of bone.

• Includes mammals, fish, birds, reptiles and amphibians.

What are Dichotomous Keys?

• a method for determining the identity of something (like the name of a butterfly, a plant, a lichen, or a rock) by going through a series of choices that leads the user to the correct name of the item.

• Dichotomous means "divided in two parts".

Using a dichotomous keyAt each step of the process of using the key, the user is

given two choices; each alternative leads to another question until the item is identified.

1a. If the leaves are flat….go to question 4. 1b. If the leaves are needle-like….go to question 2.2a. Are the needles in a bunch? Go to question 52b. Are they spread along the branch?“…pine tree

Eventually, when enough questions have been answered, the identity of the tree is revealed.

Dichotomous Keys

• Identification key that contains pairs of contrasting descriptions.

• After each description the key either directs you to another comparison or identifies the object.

1a Butterfly exhibits only one color. Boring butterfly

1b Butterfly has two or more colors. Go to 2.

2a. Butterfly has a red body.

2b Butterfly has a black body. Go to 3.

3a. Butterfly contains the color red. Inachis io

3b. Butterfly contains the color orange. Danaus plexippus