Biodiversity

• Define species

  A group of organisms which can interbreed and produce fertile offspring
• Define classification

  The process of arranging organisms into groups
• What is a sterile organism?

  Can interbreed but does not produce fertile offspring
• Categories of Classification

  DomainKingdomPhylumClassOrder FamilyGenus Species
• Mnemonic for classification


  Dear King Philip Came Over For Great Spaghetti
• How is a diagram defined as heirachy?

  -smaller groups within larger groups -no overlaps
• How are organisms classified?

  1. Artificial classification= divides groups and organisms based on analogous characteristics (characteristics that have the same function but different evolutionary origins)2. Phylogenetic classification= divides groups and organisms based on homologous characteristics (characteristics that do not have the same function but do have the same evolutionary origin)Scientists use phylogenetic classification
• How are phylogenetic relationships determined?

  1. Structural similarities 2. DNA3. Fossil records
• The Binomial naming system


  The system of naming organisms with two parts1. Genus2. SpeciesEg. Canis lupus (Grey Wolf)Can be written as C. Lupus (after written once)Genus has a capital letter, species is lowercase
• What is biodiversity?

  What is biodiversity?1. Number of different species in a particular area at a different time (species richness)2. Number of organisms of each species (species evenness)Definition= the number of species and the number of individuals of each species in a specified region and time
• What is courtship behaviour?

  Courtship behaviour enables individuals to:-Recognise a member of their own species ( to produce fertile offspring)-Identify a mate that is capable of breeding -Form a bond -Synchronise mating (so there is a maximum probability of sperm meeting an egg)
• What is a phenotype?

  The differences in genes reflected in the appearance of an organism (the expressed allele)
• Organisms that are more closely related should look more similar to each other, however there are some limitations:

  -Effect of the environment -Polygenic (more than one gene codes for the same characteristic)
• What sequences provide the best means for comparison?

  Non-coding sequences provide the best means for comparison as mutations will occur and remain in these sequences as they do not affect the survival of the organism.
• What is gene technology?

  Sampling DNA or mRNA in order to read and compare base sequences of organisms, alternatively the amino acid sequence can be studied
• Immunological Techniques


  -Serum albumin from species A is injected into species B-Species B produces antibodies specific to all the antigen sites on the albumin from species A-Serum is extracted from species B (contains antibodies specific to the antigens on the albumin from species A)-Serum from species B is mixed with serum from the blood of a third species C-The antibodies respond to their corresponding antigens on the albumin in the serum from species C-The response in the formation of a precipitate)-The greater the number of similar antigens, the more precipitate is formed and the more closely the species is related-The fewer the number of similar antigens, the less precipitate is formed and the more distantly the species are related
• Measuring diversity within a community

  
• 5 things humans do which affect biodiversity

  1. Climate change2. Deforestation3. Overexploitation4. Invasive species 5. Pollution
• Problems with agriculture and possible solutions

  Problem: Creating monoculturesSolution: Crop rotations or intercroppingProblem: Overgrazing of landProblem: Removal of hedgerows and replace with fencesSolution: Keeping hedgerowsProblem: Eutrophication as a result of increased use of fertilisers to increase yieldSolution: Limit use of fertilisersProblem: Filling in ponds/ draining marshProblem: Use of pesticides Solution: Use biological control (natural predators)
• A few other ways to maintain biodiversity

  -Plant trees on land with low biodiversity-Create natural meadows where possible -Introduce conservation headlands