TODAY'S ACTIVITY - Genes and alleles 17th February 2014

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/classification_inheritance/genesandinheritanceact.shtml



UNDERSTANDING GENES AND ALLELES


This is called a karyotype. Notice that the chromosomes have been paired up with similar sized chromosomes. One of each chromosome pairs comes from each parent
This is called a karyotype. Notice that the chromosomes have been paired up with similar sized chromosomes. One of each chromosome pairs comes from each parent

Activity on making a karyotype -

http://learn.genetics.utah.edu/content/chromosomes/karyotype/



  • A gene is a section of DNA on a chromosome, it codes for a protein that can lead to a characteristic being shown in an individual

This is a pair of homologous chromosomes. The gene shown here is for flower colour. Notice how this gene has 2 alleles. In this case, the 2 alleles are different
This is a pair of homologous chromosomes. The gene shown here is for flower colour. Notice how this gene has 2 alleles. In this case, the 2 alleles are different

  • Every gene has 2 alternative forms; these 2 forms are called alleles. We may get the same allele from our parents or 2 different ones as shown below




external image dominantrecessivealles.gif


http://scienceprimer.com/Alleles-genotype-phenotype