dna , evolution and genetic modification

• How are base pairs bonded together in a molecule?

  base pairs are bonded so that they are complimentary to each other and are held together by hydrogen bonds.
• Why did the classification system become ?

  • the discovery of archaea through dna analysis shows that they are genetically different.
• how do fossils show time periods?

  • fossils are the main source of evidence and have a smaller brain so therefore have a smaller skull
  • fossils are found in deeper layers of rocks around the grouns
• what is the process of genetic engineering?

  1. the desired gene is obtained using restricting enzymes , leaving sticky.
  2. the same restricting enzymes used would be used to open the plasmid
  3. This gene will then be inserted to the plasmid using ligase joining the complimentary sticky ends together creating recombinant DNA
  4. The plasmid would be inserted into the the cell to produce desired characteistcs.
• why can't we see fossils from further years

  they were soft bodied meaning the decayed very quickly
• system order?

  • kingdom
  • phylum
  • class
  • order
  • family
  • genus
  • species
• domain system?

  • eukaryota
  • bacteria
  • archea
• ardi?

  • structure which shows that they climbed trees and had long arms and short legs whilst also having a small brain
• lucy?

  arched feet that were more adapted to walking

  human length arms and legs

  larger brain

  walked upright more efficiently
• Leaky's fossils?

  short arms and long legs more like a human

  larger brain size

  feet better adapted to walk upright
• describe transcription

  • RNA polymerase attaches to a part of the DNA which does not code for a protein
  • RNA polymerase separates the two strands of DNA so it can access the nucleotides
  • RNA polymerase makes a strand of mRNA by linking RNA nucleotides together . this mRNA strand is complementary to the DNA
• describe translation

  • a ribosome then attaches to the mRNA in the cytoplasm
  • a ribosome moves along an mRNA strand and reads each triplet codon
  • the ribosome joins together the amino acids carried by the tRNA
  • this forms a polypeptide , the type of protein depends on the sequence of amino acids and the protein will fold into shape
• how is tissue culture performed ?

  • take the plant that is needing to be cloned
  • using tweezers , remove a piece of tissue from a fast growing regieon of the plant
  • using an aseptic technique , place the tissue on a special growth medium
  • once the tissue has developed enough, it can be transferred to compost for further growth
• advantages of tissue culture ?

  • produces a lot of offspring with desired feature
  • helps extreemely endangered species
• disadvantages of tissue culture ?

  clones have low survival rate

  gene pool is reduced by producing clones
• what are monocolonial antibodies

  identical antibodies which have been produced from the same immune cell
• why are mc special

  they can bind to only one protien and antigen meaning that they can be used to target chemicals and cells in the body
• how are mc produced ?

  • scientists obtain mice lymphocytes which are stimulated to produce a specific antibody
  • they are combined with tumour cells to form a cell called hybridoma
  • these divide to produce clones of itself which produce the same antibody
• how are mc used in pregnancy tests?

  • on one of the sticks section , mobile antibodies are complementary to HCG hormone which are attached to blue beads
  • the second end has stationary antibodies complementary to HCG hormone
  • when someone urinates on the first section and HCG is present , it binds to the MA to form HCG
  • these are carried in the flow of liquid to the second section
  • the stationary antibodies then bind to the HCG
  • as they are bound to blue bead ,it binds to a blue line indicating pregnancy
• advantages of mc?

  • only bind to specific cells so healthy cells aren't affected
  • can treat many different diseases
• disadvantages of mc?

  • difficult to attatch to drugs
  • triggeres and immune response when used in humans