biodiversity and classification

• classification

  sorting or grouping things according to similarities and differences
• taxonomy

  naming and classifying wide range of living things
• Aristotle classified organisms into two groups plants and animals
• Aristotle classified plants into two groups herbs, shrubs, and trees.
• Aristotle also classified them in the way that they move [flying, walking, or swimming]
• After the 19th century, all organisms were classified according to physical appearance, scientists studied the anatomy of organisms based on their differences and similarities
• second half of the 19th century scientist began to stress the use of evolutionary relationships in their classification system. This meant scientists do not rely on competitive anatomy instead they used paleontology, embryology, physiology, and genetics.
• examples of classification systems

  two kingdom system, five kingdom system, and three domain system
• two kingdom system

  living organisms placed in two large groups or kingdoms, kingdom Animalia and kingdom Plantae.
• examples five-kingdom system

  kingdom Monera, kingdom Protista, kingdom fungi, kingdom Plantae, and kingdom Animalia
• prokaryote

  an organism that does not have a definite nucleus.
• eukaryote

  an organism with a definite nucleus
• autotrophic

  organisms able to manufacture their food using light energy
• heterotrophic

  organisms unable to manufacture their own food instead they obtain their food from other living organisms
• saprophytic

  growing in or on dead organic matter
• saprotrophic

  feeding on dead organic matter
• decomposers

  heterotrophic organism that feeds on the dead remains of animals
• unicellular organisms

  organism made of one cell
• multicellular

  organism that is made of many cells
• three-domain system of classification

  domain archaea, domain eubacteria which is from the kingdom Monera, and domain Eukarya which consists of the kingdom Protista, Fungi, Plantae, and Animalia.
• kingdom Monera

  bacteria are the smallest living organisms, and they can only be seen with a microscope. All bacteria species have DNA but no nuclear membrane[no definite nucleus]
• parasites

  heterotrophic organisms that obtain food from living organisms
• pathogenic

  bacteria or parasites that cause disease
• mutualism

  bacteria that live in or on plants and animals that benefit both organisms
• kingdom Protista


  a large group of protists [algae] are plant-like, protozoans are animal-like, slime moulds similar to fungi but look like moulds and produce spores.
• kingdom fungi

  mushrooms and yeast are examples of fungi, they are different from plants because they do not have chlorophyll, all fungi reproduce spores but lack chlorophyll
• kingdom Plantae

  organisms in this kingdom have similar characteristics like they all have cell walls all are multi-cellular, all have chlorophyll, plants are multicellular
• kingdom Animalia

  common characteristics in animals are they are all multicellular, all of them have cells with cell walls, and all do not have chlorophyll. Animals are motile because they are able to move, fungi secret enzymes onto their food outside their bodies to absorb the food, and animals use enzymes to digest their food after they have ingested their food