IBBiology: SLDPRevision Notes3. Genetics3.1 Genes & Chromosomes3.1.10 Skills: Using Databases

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First teaching 2014

Last exams 2024

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Skills: Using Databases (DP IB Biology: SL)

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Use of Databases to Identify Gene Loci

Use of databases to identify the locus of a human gene and its polypeptide product

  • Following the sequencing of the whole human genome, we now know the exact locus (position) of every gene across the 23 pairs of chromosomes
  • Online databases have been built that are able to locate any known gene or allele
  • Anyone can access these loci
    • One example is the European Molecular Biology Laboratory database (EMBL)

  • Examples of genes that can be located are
    • The CFTR protein, critical to cystic fibrosis, on chromosome 7
    • HBB, a faulty allele of which is the cause of sickle-cell anaemia, on chromosome 11
  • If we know the locus of a particular gene, medicine can establish the location of a faulty allele, which is often recessive
    • A faulty allele can be cut out of the chromosome by genetic engineering using recombinant DNA technology
    • Replacing a faulty allele could lead to genetic therapy
    • Location databases of cancer-related genes are often vital information to researchers, doctors and patients involved in cancer genetics

    • Use of Databases: Comparing Base Sequences

    Use of a database to determine differences in the base sequence of a gene in two species

    • The Genbank® database is another that can be used to search for DNA base sequences
      • Uses a computer data analysis technique called BLAST (Basic Local Alignment Search Tool) to spot and 'line up' similar base sequences

  • A protein common to all organisms is cytochrome C
  • This makes its gene sequence a good one to compare between organisms
  • The sequence is available for many different organisms across all three domains
  • This gives important information about evolutionary relationships between organisms

    • Bioinformatics, downloadable AS Level & A Level Biology revision notes

    The use of databases to compare base sequences (and protein sequences) between species

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    Phil

    Author: Phil

    Phil has a BSc in Biochemistry from the University of Birmingham, followed by an MBA from Manchester Business School. He has 15 years of teaching and tutoring experience, teaching Biology in schools before becoming director of a growing tuition agency. He has also examined Biology for one of the leading UK exam boards. Phil has a particular passion for empowering students to overcome their fear of numbers in a scientific context.