Taxonomy and Classification

  1. Classification
  2. Importance of
  3. Work with a diversity of life
  4. Organizes organisms in a logical manner
  5. Assign a universal accepted name to each organism.
  6. Biological Classification
  7. Artistotle was one of the first people to classify living organisms
  8. Carolus Linnaeus developed a system for naming plant and animals that is still in use today.
  9. This system is called Binomial Nomenclature
  10. Each organism has a two part name
  11. The genus is the first name and is always capatilized
  12. The species is the second part of the name and is lower case.
  13. Both names are either underlined or Italicized.
  14. ex. Human = Homosapien

Homo = the genus

sapien = species

  1. After naming the organisms, Linnaeus grouped them together according to the body structures they shared.
  2. Groups which organisms are classified in are called taxa and the science of naming organisms is called taxonomy.
  3. the smallest taxa is the species
  4. if organisms share many features but are clearly separate biological units, they are classified as a different species but in the same genus.
  5. The system of grouping organisms is as follows:
  6. Kingdom
  7. Phylum
  8. Class
  9. Order
  10. Family
  11. Genus
  12. Species

So if we classify a human it would be as follows

Kingdom-Animalia

Phylum-Chordata

Subphylum-vertebrata

Class-Mammalia

Order-Primates

Family-Hominidia

Genus-Homo

Species-sapien

v. There are 3 domains to classify organisms under; classified based on rRNA

1. Archaea: include the kingdom Archaeabacteria

2. Bacteria: include the kingdom Eubacteria

3. Eukarya: which includes the kingdoms protista, fungi, plantae and

Animalia

vi. The six kingdoms are:

  1. Archaeabacteria-ancient bacteria that live in extreme

environments;

2. Eubacteria: (bacteria and blue-green algae)-they are

prokaryotic organisms.

3. Protista (paramecium, amoeba, euglena which are protozoans, and

the volvox and sprirogyra which are the algaes.)

4. Fungi (mushrooms and yeast)

5. Plantae (plants)

6. Animalia (invertebrates=no backbone and vertebrates=have a

backbone)

II. Viruses

  1. Structure
  2. Viruses are not considered to be living organisms, therefore they do not fall into any of the kingdoms above.
  3. Viruses are composed of a protein coat called a capsid and nucleic acid (RNA or DNA)
  4. An example of a virus is the bacteriophage, which attacks bacteria.
  5. Viruses vary in size from 20 to 400 nanometers (one billionth of a meter).
  6. Specific viruses infect specific organisms (hosts)
  7. Ex. A plant virus cannot infect an animal unless it mutates (Avian Flu)
  8. Viruses are pathogens (disease causing).

  1. Life Cycle
  2. In order to reproduce, viruses must invade or infect a living host cell.
  3. Infect-injects their DNA into the cell of the host
  4. The host can’t tell the difference between its own DNA and a viruses DNA
  5. the viruses enzymes destroy the hosts DNA but not its own!
  6. Replication-it uses the materials of the host cell to make thousands of copies of itself.
  7. host cell becomes filled with viral DNA molecules
  8. can occur as fast as 25 minutes depending on which virus is attacking.
  9. The infected cell bursts and releases hundreds of virus particles that infect other cells.
  1. Archaeabacteria
  2. Ancient bacteria
  3. Survive extreme environments like when life 1st began
  4. Extreme thermophiles-“heat lovers”.
  5. Extreme halophiles-“salt lovers”
  6. Methanogens-“methane makers”, anaerobic

III.Kingdom Eubacteria (Monerans)

  1. Prokaryote organisms (no nucleus)
  2. Unicellular
  3. Reproduce through binary fission or conjugation
  4. They can cause disease.
  5. Antibiotics can kill them
  6. Different shapes: cocci (round), bacillus (rod shaped) and Spirilli (spiral shaped).
  7. They do not have membrane bound organelles (only ribosomes) and they have a cell membrane and cell wall.
  8. They are autotrophs and heterotrophs

IV.Kingdom Protista

  1. Most single celled (unicellular)
  2. Eukaryotes (have a nucleus)
  3. 2 categories: protozoans-animal like; algae-plant like
  4. Algae is a protista that has a chloroplast (unlike the animal-like protists with no chloroplast)
  5. They reproduce by binary fission and conjugation
  6. Movement varies between species; some have cilia, flagella or a psuedopod which is a false foot.
  7. Ex. Paramecium, euglena, amoeba
  1. Fungi
  2. These are multicellular organisms
  3. Eukaryotic
  4. Heterotrophic, use absorption to feed as well.
  5. They have an asexual and sexual reproductive stage
  6. They have a cell wall made of chitin.
  7. Examples: mold, yeast, mushroom, mildew
  8. Plantae
  9. Multicellular
  10. Go through photosynthesis
  11. Eukaryotic
  12. Have chloroplasts
  13. Have a cell wall made of cellulose
  14. Alteration of generations (sexual and asexual mode of reproduction).
  15. Ex. Moss, ferns, pine and flowering plants
  1. Animal Kingdom
  2. Eukaryotic
  3. Multicellular
  4. No chloroplast (heterotrophs)
  5. No cell wall
  6. Lower animals like sponges have asexual reproduction; higher animals have sexual reproduction.
  7. Ex. Inverts and vertebrates

Animal Characteristics

1.Levels of organization

a. become higher as animals become more complex

b. start with organelles→cells→tissue→organs→organ system→organism

2. Symmetry

a. Radial symmetry-simplest animals have this

-no real head

-many are sessile (don’t move)

-body parts repeat around an imaginary line drawn thorugh the center of the

body.

  1. bilateral symmetry
  2. more complex animals have this
  3. body parts that repeat on either side of an imaginary line drwn down the middle of the body. One side is the mirror image of the other.
  1. animals with bilateral symmetry have front and back ends
  2. Anterior-front end
  3. Posterior-is the back end
  4. Dorsal-upper side
  5. Ventral-lower side
  1. most animals have a concentration of organs and nerve cells in their head region called cephalization
  2. small clusters of nerve cells are called ganglia

**Order of Phylums in Kingdom Animalia**

-Phylums increase in complexity (sponges are the most primitive)

1. Porifera (pore bearing)-sponges

2. Cnidaria (stinging cells)-jellyfish, coral, sea anemones

3. Platyhelminthes (flat worms)-flatworms

4. Nematoda (round worm)-roundworms

5. Mollusca (soft body)-squid, octopus ,snails, and clams

6. Annelida (little rings→segmented body)-earthworms

7. Arthropoda (jointed foot-exoskeleton)-crabs, shrimp, insects, millipedes, centipedes,

spiders

8. Echnidermata (spiny skin)-starfish, sea urchins, sea cucumbers

9. Phylum: Chordata-have a notochord, nerve cord and gill slits

Subphylum: Urochordata-sea squirts

  1. in larval stage they are bilateral and have a notochord
  2. in adult form they are no longer bilateral, and no longer retain their notochord

Subphylum: Vertebrate (have a backbone)

  1. Class Agnatha-jawless fish
  2. Class Chondricthyes-cartilagenous fish (sharks, rays and skates)
  3. Class Osteichthyes-bony fish
  4. Class Amphibia-Frogs, toads, salamanders
  5. Class Reptilia-alligators, crocodiles, snakes and turtles
  6. Class Aves-birds

7.Class Mammalia-kangaroos, people, whales, gorilla’s etc.