Science Test 1 Revision

• Taxonomy


  A branch of science that groups and names organisms based on their relationships
• Classification


  • The process of sorting things into groups
  • Biologists use classification to identify and name organisms
• Biologists group organisms based on their similarities and differences
• First Nations classification systems


  • Differ in many respects from Linnaean taxonomy
  • Include criteria that links the organism's use, age, stage in life cycle, sex, social status and totemic association
  • Totemic refers to a spiritual connection between a group of people or an individual and a specific animal, plant or natural object
• First Nations classification criteria


  • Edible or inedible
  • Totemic or non-totemic
  • Use (alive or dead)
• Taxonomy is the study of relationships between organisms and formally classifying and naming them based on these relationships
• Taxonomy used to simply consider the physical similarities between organisms, but now also considers genetic similarities
• Hierarchical classification


  Smaller groups are placed within larger groups, with no overlap between groups
• Kingdom


  The highest and broadest classification on the Linnaean taxonomic rankings
• Phylum


  The taxonomic ranking below kingdom and above class
• Species


  The most specific taxonomic ranking below genus
• Scientists have classified nearly 2 million species on Earth, but current estimates for the number of species that actually exist ranges hugely
• Of the 4 billion species that have existed on Earth, 99.9% are now estimated to be extinct
• Carl Linnaeus


  A Swedish botanist who developed the basis of the classification system still used today, known as the Father of Taxonomy
• Linnaeus realised the classification system used at the time was not working, with animals being categorised by whether they were wild or tame, or if they were big or small, and plants being given overly descriptive names
• Linnaeus sorted organisms into hierarchical groups based on their physical similarities, developing the levels of classification: kingdom, phylum, class, order, family, genus and species
• Linnaeus managed to classify over 13,000 organisms during his life
• Rules for writing scientific names


  • The first part (genus) is written with a capital letter
  • The second part (species) starts with a lowercase letter
  • Italics should be used if typing
  • Underline if writing by hand
• The species (second part of the name) is used to identify specific organisms, as they share many similarities but are all unique
• The 9 phyla


  • Poriferans
  • Platyhelminthes
  • Annelids
  • Cnidarians
  • Nematodes
  • Molluscs
  • Arthropods
  • Echinoderms
  • Chordates
• Binomial nomenclature is the biological system of naming the organisms in which the name is composed of two terms, where, the first term indicates the genus and the second term indicates the species of the organism
• Grouping organisms based on what they look

  like considers an organism’s morphology.
• When making keys, some characteristics, like colour,

  size and shape, are not so useful as these characteristics can

  change over time, or with the seasons.
• Bacteria


  • Prokaryotic
  • Not as old as archaea, appearing about 2.5–3 billion years ago
  • Human bodies are home to approximately 100 trillion 'good' bacteria, mostly found in the gut
  • Decompose waste material
  • Can increase the productivity of soil
  • Used to produce food (miso, tempeh, cheese, yoghurt) and industrial materials
  • Some are disease-causing
• Protistia


  • Eukaryotic
  • Mostly unicellular but can be multicellular
  • A group of organisms that do not fit into any other kingdom: some scientists call this kingdom the junk drawer! As a result, organisms in this kingdom are very diverse
  • Many are parasites and cause disease, such as Plasmodium that causes malaria or Giardia that causes giardiasis
  • Phytoplankton protists are photosynthetic and produce almost half of the oxygen on Earth
• Parasite


  An organism that lives in or on another organism and takes its food from its body
• Non-vascular plants


  • Do not have specialised cells that can transport water and nutrients from one part of the plant to another
  • Cannot grow very big
  • Often found spread across rocks or the ground in cool, moist, shaded areas
  • Reproduce using spores (a single-celled reproductive unit)
  • Include mosses, liverworts and hornworts, and some algae
• Vascular plants


  • Have specialised vascular tissue made of specialised cells that can transport water and nutrients around the plant
  • Ferns, non-flowering plants and flowering plants all have vascular tissue that make up stems and roots
• Flowering plants


  • Produce flowers and fruits that allow them to reproduce
  • Use brightly coloured flowers and sweet nectar to lure insects, birds and other animals that can help spread pollen to produce seeds
• Ferns


  • Some of the earliest land plants, existing on Earth for approximately 360 million years
  • Reproduce using spores
  • Do not produce seeds
  • Grow well in moist, humid, shaded areas
• Non-flowering plants


  • Include cycads and conifers
  • Reproduce using seeds that are exposed or in cones, not enclosed in fruit
  • Male cones produce pollen that fertilises female cones
  • Female cones protect the seeds
• Fungi


  A group of organisms that include mould, mushrooms and yeast
• Fungi


  • They are not producers so cannot produce their own food
  • They digest organic material and absorb the nutrients
• Fungal reproduction


  Spreading spores
• Fungal cells


  • Surrounded by a rigid cell wall made of chitin
  • Provides structural support and protection
  • Distinguishes them from other organisms
• Fungi, bacteria, archaea and protists

  • They are decomposers
  • They grow well in warm, moist conditions
• Fungi have one of the most important roles on Earth
• By decomposing waste material and dead matter, fungi release vital nutrients that can be recycled back into the ecosystem