Genetic variants

• Genetic variants are small changes in the order of bases that make up a strand of DNA
• Genotype refers to the genes present in the DNA of an individual, whereas phenotype refers to the visible effects of those genes
• A genetic variant in coding DNA alters the sequence of bases and changes the sequence of amino acids, thus altering the final structure of the protein produced
• Most mutations do not alter the protein or only do so slightly, but some can have serious effects by changing the protein's shape
• Mutations can also occur in the non-coding parts of DNA that control whether the genes are expressed
• Alleles, different forms of the same gene, lead to differences in inherited characteristics as they code for different forms of the same protein
• In monohybrid inheritance, a Punnett square diagram is used to determine the probability of offspring having certain genotypes and phenotypes based on the alleles inherited from the parents
• Uppercase letters represent dominant characteristics, while lowercase letters represent recessive characteristics in genetic diagrams