Topic 1 - Classification and Biodiversity

• How do we classify organisms

  Living things are classified according to their:

  • Morphological features
  • DNA analysis
• Five Kingdom System (morphological features)


  Groups:

  1. Bacteria
  2. Single celled organisms
  3. Fungi
  4. Plants
  5. Animals
• Three Domain System (analysis of DNA)


  Groups:

  1. Ancient bacteria
  2. Bacteria
  3. All other organisms with a nucleus
• Classifying Plants

  Flowering Plants: rely on pollination to disperse their seeds which requires insects to spread pollen

  • Daisies
  • Roses
  • Dandelions

  Non Flowering Plants -

  • Mosses
  • Ferns
• Classifying Animals

  Vertebrates - have a backbone

  • Birds
  • Snakes
  • Humans

  Invertebrates - don't have a backbone

  • Insects
  • Spiders
• Level of classification

  More similar towards genus

  1. Kingdom
  2. Phylum
  3. Class
  4. Order
  5. Family
  6. Genus
  7. Species
• Genus -

  • First part of an organisms' scientific name
  • Starts with a capital letter
• Species -

  • Second part of an organisms' scientific name
  • Starts with a lowercase
• An adaptation is a special feature that allows an organism to survive better in their environment
• Morphological adaptations (structural adaptations/what they look like)

  Examples:

  • Ear length - small ears = less heat loss due to small surface area
  • Coat colour - camouflage - able to hide from predators
  • Body mass - less heat loss through an animal with a large body mass
• Behavioural adaptations

  Example:

  • Fennec fox is nocturnal - it hunts at night because it's cooler
• Organisms that are better adapted to the environment can reproduce
• Animals compete for...

  • Food
  • Water
  • Mates
  • Habitat
• Animals population can be affected by...

  • Disease
  • Number of predators
  • Pollution
• Plants compete for...

  • Light
  • Water
  • Minerals
  • Space
• Plants populations can be affected by...

  • Pollution
  • Disease
  • Number of herbivores eating them
• Interspecific competition

  • Animals from different species competing for the same resource
• Intraspecific competition

  • Animals from the same species competing for the same resource
• The binomial system

  • All organisms are given a two part scientific name
  • This is used as they are universal
  • The names are the same in all languages to avoid confusion
• Biodiversity

  • Biodiversity is the measure of the variety of different species and the numbers of each of those species in a particular area
• Importance of Biodiversity

  • Provides food and potential foods
  • Industrial materials
  • New medicines
  • Enhances human well-being
• Protecting Biodiversity

  • National parks
  • Seed/sperm banks
  • Local biodiversity action plans
  • Captive breeding programs
• Biological control

  • Use of a species to control the population size of another species by killing of the pests
• Chemical control

  • Involves the use of pesticides and can poison the environment
• Advantages of biological control

  • It is specific to a particular pest
  • Once the predator is established, there is no need to reintroduce it at a later date
  • The pest does not develop resistance to the predator
• Disadvantages of biological control

  • There is a delay between introducing the predator and a reduction in the pest
  • It does not completely eradicate the pest, only brings it's number down to acceptable levels
• Invasive species

  • A species introduced that has a negative effect on the environment
• A lot of research needs to be carried out for biological control to ensure that any alien species introduced into a habitat does not become invasive and to prevent any species introduced having a negative effect on a non-targeted species
• Measuring Biodiversity in Plants

  Random Sampling

  Random Sampling - a method used to measure the abundance of organisms in a location using quadrats to study this and by picking random sets of coordinates to avoid bias

  Step by step method:

  1. Randomly throw a quadrat (usually 1m^2 grid)
  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

  Example:

  Total number of cockles in sample = 3

  Whole area = 850

  3×850 = 2550 cockles (estimate)
• Measuring Biodiversity in Plants

  Line Transect/Systematic Sampling

  Line Transect/Systematic Sampling - method used to measure the abundance of organisms often moving towards or away from a changing abiotic factor (e.g. forests) and it is a biased method as you measure at specific intervals

  Step by step method:

  1. Place a line transect across the length of a body of land and record the number of 3 different species of organisms at regular intervals of 2,4,6,8,10m using quadrats
  2. Repeat step one 3 times to improve confidence in results
  3. Record results in a table and calculate a mean result
• A transect line is often a tape measure or a rope
• Transects often show

  • Frequency of a species in a habitat
  • Distribution of species in a habitat
• To improve accuracy of data when measuring biodiversity in plants

  • Sample area must be typical of the whole area
  • Increase sample size
  • Method of sampling mustn't affect the results
• Measuring Biodiversity in Animals

  Capture/Recapture technique

  Step by step method:

  1. Carefully collect organisms found in 1 area without trampling habitat or leaving litter
  2. Mark the organisms and return them to the same area they were collected from
  3. Leave time for organisms to reintegrate into their community
  4. Return and again collect as many organisms possible and collect data on those already marked and unmarked from the second sample
  5. Use an equation to calculate the estimated population size
• Equation for Capture/Recapture technique

  N = MC÷R

  N = estimated population size

  M = number of animals captured and marked on the first visit

  C = number caught on second visit

  R = number caught that were marked on second visit
• Measuring Biodiversity in Animals

  When using the capture/recapture technique we must ensure that...

  • There is no death
  • No immigration or emigration
  • Marking technique doesn't affect chances of survival
  • Enough time has passed between the two samples so the marked can mix with the rest of the population
  • No destruction of a habitat or litter left
  • Marking technique doesn't affect chances of being recaptured