Living Organisms: Taxonomy, Kingdoms, Classification, and Types Essay

Submitted By motica
Words: 2104
Pages: 9

The beginnings of life:
- The earth is 4,567 billion years old.

Sequence of evolution of living things:
• atoms
• atoms replicate(replicator).
• First prokaryotic cell( survived in CO2 and water).
• Organisms began to use light as an energy source-photosynthesis(oxygen was produced and was toxic).
• Oxygen and UV combine to create the ozone layer( the atmosphere was formed).
• bacteria and archaea, and eukaryotes combine...endosymbiosis.
• Small organelles like mitochondria and chloroplast fuse into larger cells.
• plant, animal, fungi lines begin to form
• multicellular plants and water animals form.
• the evolution of the amniotic egg allowed the eggs to be laid on land.
• homo sapiens arise.

-The science of classifying organisms is called Taxonomy (categorize all living things and speak in a language that all scientists understand). System based on an organism structure, the more features in common, the closer the relation.
Binomial nomenclature:
-the first part indicates genus and the second part indicates species.

-Kingdom Less similar(broad category)
-Species Very similar(narrow category)

Each different level of hierarchy is called a taxon.
Memory device( "King Philip Could Order Four Good Salads")

Kingdom Animalia:
-Cells do not have cell walls.
-All are multicellular.
-All are heterotrophs.
-Most reproduce sexually.
-Live in terrestrial and aquatic habitats.
- Includes invertebrates(no backbone) and vertebrates( backbone)
-clam, fish, turtle, cat, human.

Kingdom Plantae
-Cell walls contain cellulose.
-All are multi-cellular.
-Most reproduce sexually and asexually.
-Have chloroplasts.
-Mosses, fern, seed, plants.

Kingdom Archaebacteria
-bacteria that live in extreme conditions.
-Bacteria in volcanoes.

Kingdom Eubacteria:
-Simple organisms lacking nuclei (prokaryotic)
-Either heterotrophs or autotrophs.
-Can reproduce asexually.
-Bacteria that are found everywhere
- E. coli.

Kingdom Protista:
- Found in many places, some terrestrial, some aquatic.
-Some have chloroplasts.
-Most are single celled.
-Some are autotrophs, some heterotrophs, some both.
-Reproduce sexually and asexually.
-Amoeba, paramecium.

Kingdom Fungi:
-Similar to plants but unable to carry out photosynthesis.
-Most are multi-cellular.
-Have cell walls but not made of cellulose.
-Reproduce sexually and asexually.
-Most are terrestrial.
-Yeast, mushrooms, mould.

Kingdom Archaebacteria/Eubacteria:

Beginning theory of microbiology:
-Theory of spontaneous generation( Aristotle)
-Invention of microscope(Jansen)
-First sketch of cells(Hooke)
-Every cell is derived from a pre-existing cell(Raspail)
-All living things are composed of cells and cell products(Shwann)
-Cell is the basic unit of life(Braun)
-Where a cell exists, there must have been a pre-existing cell(Virchow)
-Louis Pasteur disproves "theory of spontaneous generation"

Cell theory:
-All living things are composed of one or more cells.
-Cells are the basic units of structure and function in all organisms.
-All cells come from pre-existing cells.
-The activity of an entire organism depends on the total activity of its independent cells.

-Primitive bacteria.
-Survive under extreme conditions.
-Thermophiles: extreme heat.
-Methanogens: Swamps, no O2.
-Halophiles: Salty environments.
-More advanced bacteria, more common.
-All bacteria are single celled.
-All are prokaryotic(no nucleus).
-Cell organelles are not surrounded by membranes.
-DNA is made of a single chromosome in a ring called a plasmid.
-Most reproduce asexually.