2.1 - classification & biodiversity

• Classification means putting organisms into groups based on shared characteristics
• organisms can be classified by:

  • physical features (morphological)
  • DNA analysis
• There are 5 kingdoms:

  • Plants
  • Animals
  • Fungi
  • Protists
  • Prokaryotes
• protists are single celled organisms
• prokaryotes are bacteria
• The order of the taxonomic rank is:

  kingdom > phylum > class > order > family > genus > species
• pneumonic for the taxonomic ranks is: King Prawn Curry Or Fat Greasy Sausages
• When writing the genus, the first letter should be a capital
• when writing the species, it should all be lower case
• scientific names are important as it is the same around the world, so it avoids confusion
• Adaptations are features of an organism that increase its chance of survival. Both morphological and behavioural
• Animals compete for:

  • food
  • territory
  • mates
• Plants compete for:

  • light
  • water
  • minerals
  • space
• size of populations may be affected by:

  • competition
  • predation
  • disease
  • pollution
• The 2 types of competition are intraspecific and interspecific competition.
• intraspecific is competition within a species
• interspecific is competition between species
• biodiversity is the variety of different species in a specific area
• biodiversity help to provide resources needed to sustain life such as food, medicine and industrial materials
• there are high biodiversity in rainforests
• biodiversity can be conserved by:

  • CITES (Convention on International Trade in Endangered Species)
  • Capture breeding programs
  • SSSI (Site of Special Scientific Interest)
  • National Parks
  • AONB (Area of Outstanding Natural Beauty)
• biological control is when another organism is used to kill pests
• biological control agents are usually:

  • predators
  • bacteria
  • parasites
• alien species are organisms that has been introduced to a country it does not originate from
• alien species become invasive when they:

  • have no predators in the area and the population grows out of control
  • compete w native species and cause them to decrease in population
  • prey on native species, reducing population
  • carry disease native species not immune to
• Advantages of biological control:

  • usually specific to a particular pest
  • once a predator is established, no need to reintroduce
  • doesn't kill useful insects or cause bioaccumulation
• Disadvantages of biological control:

  • delay between introducing predators and the reduction of pest
  • biological control agent can compete with native species
  • can introduce new diseases
• random sampling reduces bias
• the two sampling methods are:

  • quadrats
  • line transects
• Quadrats are square frames used to sample an area at random.
• line transects are lines drawn across an area that are sampled at regular intervals along their length.
• transects can show the:

  • frequency of a species in a habitat
  • distribution of a species in a habitat
• The advantages of transects over quadrats is they cover more ground, but disadvantage is it takes longer to record data.
• Advantages of quadrats over line transects is quicker to collect data, but disadvantage is only samples small areas.
• capture recapture technique is a way of estimating the population size of an animal species
• capture recapture method:

  1. animals are captured, marked and released
  2. a few days later, animals are recaptured
  3. the numbers of marked and unmarked animals caught are recorded
  4. the population size is estimated using: number in 1st sample x number in 2nd sample / number in 2nd sample previously marked
• when using capture recapture data, assumptions made include:

  • there are no deaths
  • there is no mass immigration or emigration
  • the marking technique does not affect chances of survival ie. more likely to be noticed by predators or toxic to species
• scientific names are used as they are universal
• A larger sample will give a valid estimate of the number of plants in the area
• method for quadrat samplign:

  1. Randomly throw a quadrat
  2. Count the different species and the number of each in each quadrat
  3. Take a mean number of each species of plants from all the quadrats collected
  4. Multiply up to estimate how many in the whole area