Chapter 15 Classification

Chapter 15: Classification SystemsText page 319-322 Why do we need a system to classify and name organisms? Good Classification system:

1.

2. Old way was inefficient Carolus Linnaeus:

1. 2. 3. First word is capitalized ________________Second word lower case _______________Both are _______________ or _______________

 

Terms:

________________ is a category used to classify organisms.

Groups called taxa (singular: taxon)

__________________highest taxonomic level of traditional Linnaean system of classification.

__________________a taxonomic level consisting of a group of similar species.

_____________________ the science of naming organisms and assigning them to these groups.

__________________ is the smallest taxon (population of orgs that share a similar char and can breed with each other).

1

Chapter 15 Classification

Organisms that share similar characteristics but are clearly different would have ______________________________

Example:

Felis domesticus

Felis concolor

Lions: Panthera leo, Tigers: Panther tigris

All cat like genera belong to family Felidae.

Cats are in same order as dogs (family Canidae) Order Carnivora.

Orders are grouped into__________________.

Class _______________________ - _____________________________________________________________

Phylum __________________ – many differences but all have backbone ( ).

Kingdom Phylum Class Order Family Genus Species

2

Chapter 15 Classification

Species evolve from earlier species.

Taxonomy attempts to show evolutionary relationships: species shown to be closely related are classified together. Previously we found evidence of evolution in embryos, homologous structures and DNA.

Other species that may look alike but possess analogous structures only are classified in different groups. Classification becomes difficult because scientist can’t always agree on what’s most important structure in classifying organisms.

Biochemical TaxonomyBiochemical Taxonomy:

All life forms come from common descendants and share organic molecules that are almost identical from species to species. Taxonomists use these similarities to classify organisms much the same way anatomists use homologous structures in classification.

DNA- all life forms carry DNA descended from earliest life forms. All subsequent life forms share similar genetic code. Many genes are similar, which then code for similar proteins:

Cytochrome C is found in mitochondria in virtually every organism,. Found in plants, animals, and many unicellular organisms

The cytochrome C molecule has been studied for the glimpse it gives into evolutionary biology. Its amino acid sequence is highly conserved in mammals differing by only a few amino acids. For example, the sequences of cytochrome c in humans is identical to that of chimpanzees (our closest relatives), but differs more from that of horses.

The more similar two organism’s genes are _________________________

The more different, ____________________________________________

3

Chapter 15 Classification

Originally there were ______ levels of classification, now scientists have added a new one above kingdom: ______________.

Three Domains:

Domain Archaea Bacteria EukaryaKingdom Archaeabacteria Eubacteria Plantae Animalia Protista Fungi

Prokaryotic, unicellular

Prokaryotic,Unicellular

Eukaryotic, multicellar

Eukaryotic, multicellar

Eukaryotic, Unicellular or multicellar

Eukaryotic, multicellar

4

Chapter 15 Classification

Currently organisms are classified into 6 Kingdoms depending on their

The number of cells they have, The type of cells they have (complex or simple) Their nutritional needs

There are two basic types of organisms based on cell type: Prokaryotic and Eukaryotic:

Prokaryotes: Eukaryotes:

Binary Fission

Prokaryotes No ___________________ No ___________________ Reproduce by ____________________ Includes __________________-and

_______________________

Most DNA can be contained on a single chromosome.

5

Chapter 15 Classification

Kingdom Archaeabacteria (Domain Archaea)

Archaebacteria are primitive bacteria microorganisms that have one cell and are often referred to as extremophiles because they can be found living in extreme places of extreme heat like volcanoes, high salt like the Dead Sea, ice and places with no oxygen.

Cell type: Prokaryotic Some are autotrophic (can make their own food), most chemotrophic

(get their nutrients from chemical). Eg. methanogens, halophiles, and thermophiles.

The methanogens are ________________ bacteria that survive in the absence of _____________and produce ______________. They are found in _____________________________________________________________.

Halophiles are bacteria that thrive in ________________________ such as those found in salt lakes or pools of sea water.

Thermophiles are the __________________ found near __________________ and hot springs.

Archaebacteria emerged at least 3.5 billion years ago and live in environments that resemble conditions existing when the earth was young.

Research into genetic sequencing suggests that _______________________ ago __________________ diverged from _______________________, which were their predecessors.

Kingdom Eubacteria (Domain Eubacteria) Cell type:__________________________________ lack ______________________ or _____________________ have ___________________________ mostly asexual reproduction (_____________________) The most ___________________ and _________________ of the non-nucleated cellular

life forms. Found in every habitat on earth. "_____________________________" can be either ______________________ or ________________________. more common than archaebacteria. kill thousands of people each year, but also serve as _______________________ and food

digesters in our stomachs. We use eubacteria to produce _____________, ______________, ______________.

6

Chapter 15 Classification

many eubacteria form ______________, resistant to dehydration and most temperatures, when there is no food and can last up to 50 years.

3 shapes: _______________________________________________________________

Eubacteria are often divided into categories by their methods of nutrition acquisition:

Mode of Nutrition Energy Source

Photoautotroph

Chemoautotroph

Photoheterotroph

Chemoheterotroph

Examples of EubacteriaE. coliYersinia pestis-Streptococcus pneumoniae-Salmonella enterica-Cyanobacteria (blue-green algae) Lactobacillus, a type of Eubacteria which converts proteins found in milk into lactic acid, and lives benignly inside the human body.

Domain Eukarya (Eukaryotes)

Developed after prokaryotes and are more _____________________ organisms. The difference between the structure of prokaryotes and eukaryotes is so great that it is

considered to be the most important distinction among groups of organisms. True, ___________________________________________________________________ Mitochondria Includes Kingdoms:

Kingdom Animalia

Largest kingdom with over 1 million known species. Eg:

Kingdom Plantae

7

Chapter 15 Classification

With over 250,000 species, the plant kingdom is the second largest kingdom. Plant species range from the tiny green mosses to giant trees Eg:

Fungi

cell wall made of chitin (unlike plant cells with cellulose walls and animal cells, which

have no cell wall) reproduce by sexual or _______________________ (which are usually spread by air), or

_____________________________. Examples:

Kingdom Protista

the junk drawer kingdom. Examples: diatoms, ameba, paramecium, slime molds and large algae like kelp, Classified as

Plant likeFungi likeAnimal like

Create a Concept Map

Containing the three domains and their cell type, 6 Kingdoms, their defining characteristics, two examples of each

8