As hard as I try I am not going to be able to avoid all scientific terminology. To try and make things as clear as possible I have defined the key terms below:

  • DNA – (Deoxyribonuclaic acid) The very stuff that makes us as we are. DNA is the building blocks of life. It is a sequence of little elements called bases which are either A,T,C or G. For more information and to see how it works see: What is DNA?,DNA
  • Gene – A section of DNA which codes for a protein. Every living organism is made up of cells. Every cell is made up of amino acids (along with some other chemicals). Amino acids are just a configuration of proteins. Hence, a gene codes for proteins which form amino acids which form cells, building organisms and making them as they are. As genes determine what proteins are made, these ultimately determine what cells are made thus determines what the organism’s properties are. For humans this includes things like eye colour, hair type, skin colour etc… What is a gene?
  • Genome – The entire set of genes or genetic material present in a organism
  • Chromosome – A chromosome is a thread like strand of DNA. Each organism has its DNA packaged into a collection of chromosomes so that it fits in each cell. Each organism has two copies of each chromosome one which it inherited from its mother and one from its father. Chromosomes
  • Loci – The loci of a gene is the place on the specific chromosome where the gene is found. (Plural – locus)
  • Alleles – Alleles are the different forms that a gene can take. As you have 2 copies of each chromosome you have two copies of each gene. Thus you have 2 alleles for each gene which can be the same or different. Alleles can be dominant or recessive which affect the phenotype (see below)
  • Genotype – The combination of alleles found at the loci of the gene on the 2 chromosomes which are the same.
  • Phenotype – The displayed trait resulting from the genotype Genotypes and phenotypes