STM 008 (M21-23)

General Biology 2

Taxonomy

the science of classifying and naming organisms based on shared characteristics.

Aristotle

he first classified organisms into plants and animals. The problem was that microscopic organisms were not included.

Carolus Linnaeus

he further developed the two-kingdom system and unicellular forms were arbitrarily assigned to one of these kingdoms.

Plants

in this two-kingdom system, those do not move and are green in color are considered ___.

Animal

in this two-kingdom system, those who move belong to the ___ category.

Ernst Haeckel (1866)

he proposed that the Kingdom Protista shall be included to solve the problem of classifying the unicellular forms.

Kingdom Protista

this kingdom includes all the unicellular organisms.

Two-Kingdom System

a classification system proposed by Carolus Linnaeus, dividing organisms into Plantae (plants) and Animalia (animals).

Three-Kingdom System

introduced by Ernst Haeckel, adding Protista as a kingdom for microorganisms that did not fit into Plantae or Animalia.

Protist

was a catch-all category for all single-celled organisms with nuclei.

Robert Whittaker (1969)

- popularized the five-kingdom system.

- his classification is based on what type the cell is and its mode of nutrition.

Five-Kingdom System

- this system emphasizes the structural differences between prokaryotes and eukaryotes.

- it recognizes one kingdom of prokaryotes (Monera) and four kingdoms of eukaryotes (Protista, Fungi, Plantae, and Animalia)

Prokaryotes

unicellular without true nucleus.

Eukaryotes

multicellular and unicellular with true nucleus.

Monera

the Kingdom ___ contained the prokaryotes.

Protista

the Kingdom ___ contained the unicellular eukaryotic organisms (protozoa and unicellular eukaryotic algae). The multicellular organisms were split into three kingdoms in the basis of mode of nutrition and other fundamental differences in organization.

Fungi

the Kingdom ___ contained the molds and yeasts which obtain their foods by absorption of nutrients from dead decaying.

Plantae

the Kingdom ___ included multicellular photosynthetic organisms, higher plants, and multicellullar algae.

Animalia

the Kingdom ___ consisted of the vertebrates and invertebrates. Most of these forms ingest their food and digest it internally, although some forms are absorptive to some extent.

Carl Woese (1990)

proposed the six-kingdom system. The prokaryotes (Monera) are split into two kingdoms based on ribosomal RNA and other products.

Six-Kingdom System

this system includes two prokaryotic kingdoms (Archaebacteria and Eubacteria) and four eukaryotic kingdoms (Protista, Fungi, Plantae, and Animalia)

Archaebacteria

- are believed to have evolved from the earliest cells.

- they inhabit extreme environments such as hot springs and salt ponds.

Eubacteria

- are considered as the more "modern" prokaryotes.

- they are more numerous than the archaebacteria.

Archaebacteria

- the Kingdom ___ contains cell walls lack muramic acid.

- they are also called as extremophiles because they are found in harsh environments.

- many of which are anaerobic.

- this kingdom includes those that live in highly saline environment (halophiles), very hot environment (thermophiles) and in environment with methane gas.

Eubacteria

- the Kingdom ___ are the true bacteria.

- their cell walls have peptidoglycan.

- they can be autotrophic (can make own food) or heterotrophic (cannot manufacture their own food).

- this kingdom includes proteobacteria, gram positive bacteria, gram negative bacteria, cyanobacteria, spirochetes and Chlamydia.

Protista

- the Kingdom ___ is its informal name because it mostly consists of unicellular eukaryotes.

- they exhibit more structural and functional diversity than any other group of eukaryotes.

- they are most nutritionally diverse of all eukaryotes, including photoautotrophs (can produce own food), heterotrophs (absorbs organic molecules or ingest larger food particles) and mixotrophs (photosynthesis and heterotrophic nutrition).

- this kingdom also includes animal-like, plant-like, and fungus-like organisms.

Fungi

- the Kingdom ___ are eukaryotic organisms with cell walls containing chitin.

- organisms in this kingdom lack chlorophyll and are heterotrophic.

- there may be some which are unicellular or some that are multicellular.

- some obtain nutrients from dead organic matter (decomposers) and from other living organisms (parasites).

- they reproduce sexually or asexually.

Plantae

- the Kingdom ___ are multicellular, eukaryotic photosynthetic autotrophs containing chloroplasts.

- they are non-motile (fixed to one spot).

- their cell wall is made of cellulose.

- this kingdom includes the bryophytes (seedless vascular plants), ferns and allies, and the seed-bearing plants (gymnosperm and angiosperm).

Animalia

- the Kingdom ___ is multicellular and heterotrophic.

- they require oxygen for aerobic respiration.

- they reproduce sexually or asexually.

- they are motile during at least a part of the life cycle.

Some of the Characteristics That are Used to Determine Placement of the Six Kingdoms of Life

1. Cell Type

2. Nutrient Acquisition

3. Reproduction

Classification of Organism

1. Domain

2. Kingdom

3. Phylum

4. Class

5. Order

6. Family

7. Genus

8. Species

“Dean King Philip Came Over For Good Spaghetti”

Taxonomic Classification

a hierarchical system is used for classifying organisms to the species level.

Domain and Kingdom

the broadest classifications of organisms are by ___.

Genus and Species

the most specific classifications of organisms are by ___.

Phylum, Class, Order, and Family

the hierarchical systems in between include ___.

Species

- are the basic unit of classification or smallest taxon of taxonomy.

- while there are different views on what defines a ___, in sexually reproducing organisms, it has traditionally been defined by the ability of its members to reproduce together to form fertile offspring.

Taxon

a group of organisms at any particular level in a classification system.

Phylum

in plant taxonomy, a division is the equivalent to ___.

Family

a related group of genera comprise a ___.

Genus

the oldest level of taxonomic classification.

Genus and Species Names

scientific names of organisms are derived from ___.

Binomial Nomenclature

a system used in scientific names of organisms.

Species

is a group of individuals that remain relatively constant in their characteristics; can be distinguished from other species and do not normally interbreed.