Species and Taxonomy

• What is the binomial system?

  A system of naming organisms using two words:

  The Genus and then the species.

  (genus has a capital letter and both are in illatics)
• Why do different species look similar?

  1. Live in similar environments
  2. Have similar selection pressures
  3. Similar alleles will have the selective advantage
  4. Produce similar/ same proteins and therefore have similar characteristics
• What is a hierarchy? (2 marks)

  1. Smaller groups arranged within larger groups
  2. No overlap between groups
• State the order of the classification system

  Domain

  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• What is each group called in the classification system?

  Taxa
• Why do we need a classification system?

  • To understand relationships between organisms and keep track of changes
  • The system needs to be universal
• Define a population

  A community of one species that can interbreed
• Define a community

  A group of two or more different species in one area
• Define environment

  All factors affecting growth of an organism
• Define a habitat

  An area inhabited by a specific organism
• Define a species

  Two organisms that interbreed to produce fertile offspring
• Define a niche

  A role taken by a type of organism within its community.
• Define carrying capacity

  The number of a particular species that a region can support without environmental degradation
• Define Interspecific

  Occurring between species
• Define Intraspecific

  Occuring within a species
• Explain Primary Succession

  1. Pioneer species colonise bare rocks as they can withstand the harsh conditions
  2. Mosses and smaller plants can now survive and increase the depth and content of the soil. This continues as the abiotic factors become less harsh
  3. New species change the environment so it become less suitable for the pioneer species and become outnumbered by new species
  4. Changes to the abiotic environment result in a less hostile environment an increases biodiversity
  5. Final stage = Climax community (dominated by trees)
• Explain Secondary Succession

  1. Starts as a potential climax community
  2. Disrupted by human deforestation, natural disaster or fires and plants are destroyed
  3. The land is left with SOIL
  4. Succession occurs again
• What occurs during succession ?

  • Species richness increases and the number of organisms increases
  • Increases biodiversity
  • Larger plants and animals colonise an area so create more complex food webs
• Define a climax community

  An ecological community in which populations of plants or animals remain stable
• State three comparisons of genetic diversity that the scientists use in order to generate a classification

  1. The (base) sequence of DNA;
  2. The (base) sequence of mRNA;
  3. The amino acid sequence (of proteins);