exam questions

• Describe how the primary structure of trypsin molecules can be used to produce a phylogenetic tree (3)

  -       Determine the sequence of amino acids for trypsin 

  -       Determine the number of differences or similarities in sequences of amino acids between species

  -       The greater the number of differences the less closely related the species are or more similarities the more related
• explain how these 2 sloths are now classed as different species (2)

  -       They are no longer able to interbreed to produce fertile offspring 

  -       Because populations have become reproductively isolated 
• Which group to fungi belong?

  -       Prokaryota
• Which of the following contain prokaryotic organisms (1) 

  -       Archaea and bacteria
• Describe the features which could be used to identify the prokaryotic cells in the blood sample (4) 

  -       It would have a cell wall 

  -       It would have circular DNA 

  -       It may have a flagella or slime capsule 

  -       Would have plasmids 

  -       No nucleus

  -       Smaller ribosomes
• Explain how molecular phylogeny can be used to show that these 2 populations are reproductively isolated (3) 

  -       Analyse the DNA or RNA of the species in the different populations 

  -       Comparison of amino acid sequences 

  -       The more differences there are the more reproductively isolated they are

  -       So not in the same species thus cannot interbreed to produce fertile offspring
• Describe how molecular phylogeny can be used to determine the relationships between 2 cats (2) 

  -        Analyse the DNA and sequence of amino acid chains in proteins

  -        The more similarities the more closely related they are