Genome Sequencing Flashcards Preview

OCR Biology F215 > Genome Sequencing > Flashcards

Flashcards in Genome Sequencing Deck (3)
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1
Q

Outline the steps involved in sequencing the genome of an organism

A
  • genomes are first mapped to identify which chromosome or section of chromosome they have come from
  • samples of the genome are then sheared into smaller sections (shot gun approach) using restriction enzymes
  • these DNA fragments are then inserted into BACs (bacterial artificial chromosomes), each fragment is inserted into a different BAC
  • the BACs are then transferred to E.coli and as the cells grow in culture many copies of the sections are produced (clone libraries)
  • the DNA is then extracted from cells containing specific BACs and cut into smaller fragments using restriction enzymes
  • each copy is cut with a different restriction enzyme so this gives different fragment types
  • the fragments are then separated using gel electrophoresis
  • each fragment is then sequenced using an automated process (Sanger sequencing)
  • computer programmes then compare overlapping regions from the cuts made by different restriction enzymes in order to reassemble the whole BAC segment sequence
2
Q

Define the term genome

A

The entire genetic code in the cells of a single species

3
Q

Explain how gene sequencing allows for genome wide comparisons between individuals and species

A
  • can be used to ascertain how important the gene is
  • work out evolutionary relationships - the more similar the sequence the more closely related the species
  • compare the genome of a pathogenic organism with that of a similar non- pathogenic organism - enables us to find out what genes are important in causing a disease
  • identify genes which cause inherited diseases
  • investigate the effects of specific mutations by manufacturing a mutation and inserting it into a microorganism