Biology 6.2-DNA 2

• An allele is a different version of the same gene, inherited from one's parents.
• Dominant and recessive homozygous and heterozygous refer to the inheritance of genes.
• Genotype is the entire collection of alleles that one has, while phenotype is the characteristics that one gets from their genotype.
• Genes that we inherit determine the characteristics that we develop.
• Some characteristics are coded by a single gene, some are coded by several genes that interact with each other.
• Genes code for a particular type of protein.
• There are multiple forms of the same protein (with different codes for each).
• Alleles are different versions of the same gene.
• We have two copies of every gene (one from each parent) so we will have two alleles of each gene.
• Alleles can be the same or different.
• Having the same alleles means they are homozygous.
• Having different alleles means they are heterozygous.
• If the alleles are different, one will be dominant (expressed) and one will be recessive (not expressed).
• Dominant alleles will be expressed no matter what.
• Recessive alleles need two of them to be expressed.
• The phenotype is how those genes express themselves.
• Genes can have multiple alleles.
• Genes code for proteins which determine characteristics like eye colour.
• Genotype is the entire collection of alleles that an individual has for a particular gene.
• Phenotype is the expressed characteristic from the genotype.