3: Classification & Biodiversity

• What is the order of the classification system?

  Domain, kingdon, phylum, class, order, family, genus, species
• What are the three domains?

  Archaea, bacteria, eukaryotes
• What are the five kingdoms?

  Prokaryotes, protists, fungi, plants, animals
• Are eukaryotes a domain or kingdom?

  Domain
• Are prokaryotes a domain or kingdom?

  Kingdom
• Which domain do protists, fungi, plants and animals all belong to?

  Eukaryotes
• Which kingdom can fit into either the bacteria or archaea domain?

  Prokaryotes
• Are prokaryotes unicellular or multicellular?

  Unicellular
• Why is the three domain model more widely accpeted over the five kingdom model?

  The three domain model is based off of DNA sequencing, including considerations of base sequences of ribosomal RNA.
• Define species?

  A group of organisms with similiar characteristics that interbeed to produce fertile offspring.
• What are limitations of the 'reproductive model' definition of species?

  Cross-breeding occurs (when different species reproduce). Some members of the same species cannot reproduce due to geographical isolation. Doesn't account for species that reproduce asexually.
• Why is it difficult to assign species?

  Species change over time. How similiar do two organisms need to be to be the same species. Should hybrids be counted as a new species or not.
• What system is used to name species?

  The binomial system.
• In the binomial system, is the first or second word the genus?

  First
• In the binomial system, what does the second word tell you?

  The species
• What can be used to determine evolutionary relationships?

  DNA
• How can DNA be extracted from cells?

  Mechanical break down, adding detergent and salt to break down membranes, adding protease to break down histones, filtering to remove cell debris, adding ice cold ethanol to produce a DNA precipitate
• How can DNA be cut into fragments?

  Using restriction enzymes
• What is the name for when DNA is adjusted for comparison?

  DNA profiling
• What is bioinformatics?

  Biological data on huge databases generally on computers
• How can DNA fragments be seperated?

  Gel electrophoresis
• How is gel electrophoresis conducted?

  DNA sample is placed in a well in the gel, buffer solution is added to keep the pH constant, electrodes at either end have a voltage applied, DNA moves to positive electrode, the smaller the fragment the further it will move so they're seperated due to size.
• Why does DNA move to the positive electrode in gel eletrophoresis?

  DNA has a negative charge due to its phosphate group.
• Name three ways through which species can be distinguished between and evolutionary relationships can be identified?

  Gel electrophoresis, DNA sequencing or bioinformatics
• Explain the process of DNA sequencing?

  DNA fragments are chemically modified so different bases are tagged with different fluorescent markers, gel electrophoresis is used to seperate fragments, bases can be recognised due to different colours
• What are the two main considerations of classification?

  Analogous structures and homologous structures
• What three things may be involved in validating scientific evidence?

  Scientific journals, peer review and scientific conferences.
• Define ecosytem?

  A community of organisms and their surroundings plus the environment in which they live (abiotic factors).
• Define community?

  A group of different organisms living together
• Define population?

  A group of the same organisms living together
• Define niche?

  The precise conditions a species needs (feeing, habitat, behaviour with relation to other organisms).
• What are the three types of adaptations?

  Anatomical, physiological and behavioural
• What is an anatomical adaptation?

  Changes to the form or structure of an organism
• What is a physiological adaptation?

  Changes to the way an organisms body works
• What is a behavioural adaptation?

  Changes to the programmed/instinctive behaviour of an organism
• Elephants having bigger ears to loose more heat is an example of what type of adaptation?

  Anatomical
• Diving mammals redicing there heart rate when diving to minimise oxygen use is an example of what type of adaptation?

  Physiological
• Penguins huddling to preserve heat is an example of what type of adapatation?

  Behavioural.
• Outline the mechanism behind natural selection?

  Organisms sharing the same niche will compete, the one better adapted will survive and reproduce.
• What are the four causes of genetic variation within a species?

  Genetic mutations, crossing over, independent assortment & random fertilisation