genetics (key words)

• mutation


  change in DNA sequence. Can involve changes to genes or whole chromosomes.
• gene mutation


  a change in the DNA sequence of a particular gene
• chromosome mutation


  a change to a chromosome, either additional chromosome or mission chromosome
• non-disjunction


  failure of the homologous chromosomes to separate during meiosis
• polyploidy


  a condition where the cells of an individual have more than two paired chromosomes
• hybridisation


  the breeding of two populations, producing a mixture, a genetic hybrid
• haploid


  a cell containing half the number of chromosomes
• diploid


  a cell that has paired chromosomes
• diploid number


  the normal number of chromosomes present in the cells of a diploid organism
• meiosis


  the type of cell division that creates four daughter cells, each with half the genetic information in sex cells
• crossing over

  crossing over occurs during meiosis 1 leading to recombination and is the result of homogenous chromosomes partners breaking and swapping portions of their genetic material
• gene pool


  the alleles available. within a population
• allele frequency 


  the number of a certain allele available in a population - how common it is