Classification & biodiversity

• Classification systems allow us to organize living things into groups based on similarities and differences.
• The Linnaean system is the most widely used classification system.
• Biodiversity is the total number and variety of species in a given area
• Biodiversity can be studied using sampling techniques
• Organisms can be classified according to morphological features
• Scientists group similar organisms together to make them easier to identify
• Groups start big and organisms within have only a few similarities
• As you move down the groups, they get smaller and organisms have more features in common
• The biggest groups are called kingdoms
• The five kingdoms are:

  • Animal
  • Plant
  • Fungi
  • Single-celled organisms (Protoctists)
  • Bacteria
• Animal kingdom can be further split into:

  • Vertebrates: animals with a backbone (e.g., amphibians, mammals, reptiles, bony fish, birds)
  • Invertebrates: animals without a backbone (e.g., molluscs, annelids, arthropods, nematodes)
• Plant kingdom can be divided into:

  • Flowering plants produce flowers for reproduction (e.g., sunflowers, grass plants)
  • Non-flowering plants reproduce using spores (e.g., ferns, mosses)
• Biodiversity is the total number and variety of species in a given area
• Biodiversity can be studied using sampling techniques
• Organisms can be classified according to morphological features
• The classification of organisms down to species follows a particular order:

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• The binomial system of classification uses the organism's genus and species to create its name
• The binomial system is universal and Latin is used to name organisms
• In the binomial system, each organism is named for its genus then its species
• The binomial classification of an organism is written in italics, with the genus name first (capitalized) and the species name following (lower case)
• Organisms that share a genus name are closely related, but they are only the same species if both the genus and species name are the same
• The binomial classification of a tiger is Panthera tigris
• The binomial classification of a lion is Panthera leo
• Biodiversity is the total number and variety of species in a given area
• Biodiversity can be studied using sampling techniques
• Organisms can be classified according to morphological features
• Morphological adaptation is a structural change that gives an organism a greater chance of survival in its habitat
• Behavioural adaptation is the way an organism reacts to its environment to aid its survival. Example: Arctic fox in cold habitat has smaller ears and thick fur to retain body heat or Fennec fox in the desert has large ears to radiate heat and cool down and the Pangolin is nocturnal in a desert-like habitat to hunt for food at night due to heat during the day.
• Biodiversity is the total number and variety of species in a given area
• Biodiversity can be studied using sampling techniques
• Organisms can be classified according to morphological features
• Biologists estimate the size of a population by taking random samples of the area to be studied
• Using a quadrat:

  • A quadrat is usually a 1 m^2 frame made of wood
  • It may contain wires to mark off smaller areas inside, such as 5 × 5 squares or 10 × 10 squares
  • Organisms underneath, usually plants, can be identified and counted
  • Quadrats may also be used for slow-moving animals, eg slugs and snails
• To take a truly random sample with a quadrat:

  • Measure out an area to be surveyed
  • Use a random method to collect coordinates for the vertical and horizontal axes measured out
  • Select the first coordinate and move that distance along the x-axis
  • Select the second coordinate and move that distance along the y-axis
  • Place the quadrat where the coordinates meet, making sure the placement is consistent each time
  • Count the number of organisms in the quadrat
  • Repeat this procedure at least 25 times
• Estimating population size:

  • Calculate the number of organisms found in the whole area using the equation:

  (Total organisms found in sample) x (Total area) / (Total area sampled)

  
  

  Example calculation:

  Sally finds 40 flowers in a 10 m^2 quadrat in a 50 m^2 field

  She calculates the estimated number of flowers in the whole field as:

  40 x (50 / 10) = 200 flowers
• Example calculation:

  Sally finds 40 flowers in a 10 m^2 quadrat in a 50 m^2 field

  She calculates the estimated number of flowers in the whole field as:

  40 x (50 / 10) = 200 flowers
• Biodiversity is the total number and variety of species in a given area
• Biodiversity can be studied using sampling techniques
• Organisms can be classified according to morphological features
• A transect is a line across a habitat or part of a habitat