Extended Medel/Pedigree/Definitions/etc

• Codominance = both alleles are expressed equally
• Carrier = heterozygous, does not have the disease but can pass it on to offspring
• Affected = has the disease
• Recessive = only appears when homozygous (aa)
• Dominant = always appears when present (Aa or AA)
• Incomplete dominance = neither allele is completely masked by the other
• Co-dominance = two different traits appear together (AB), no blending occurs
• Mendelian inheritance = follows Mendels laws of segregation and independent assortment
• The difference between Multiple Alleles and Polygenic Inheritance is that Multiple Alleles involve the same DNA strand, while polygenic inheritance involves multiple DNA strands
• Barr Body inactivates the female X chromosome
• The chromosomes which genes are located can affect expression of traits
• Two copies of each autosomal gene affect phenotype
• Mendel studied autosomal gene traits
• Rules of Inheritance: When traits follow the simple rules of Mendelian Inheritance of dominant and recessive genes
• Complex traits follow different patterns of inheritance that may involve multiple genes and other factors. EX: Incomplete/blended dominance; Codominance; Multiple alleles
• Mendel's rules of inheritance apply to autosomal genetic disorders
• Disorders caused by dominant alleles are uncommon
• Incomplete dominance: blended phenotype/neither allele is completely dominant
• Codominance: Equally dominant and expressed at same time (both phenotypes visible)
• Multiple Alleles: involve same DNA strand but different allele variations in said strand
• Codominant alleles are neither dominant or recessive
• Codominant alleles will both be completely be expressed
• O negative is universal blood donor
• AB blood type is universal recipient
• 3 alleles determine blood type
• Polygenic Traits Examples: Eye color, Skin color, and height
• Phenotype can be affected by environment (height and nourishment; sea turtles and temperature
• Epistatic Genes: interfere with other genes; no new phenotypes produced via this gene interaction
• Regulatory Genes: Control/regulate other gene expressions (silence another gene from expressing its dominant trait.)
• Gene Linkage: Genes carried on same chromosome/ genes close together with a high chance of being inherited together
• Polygenic- multiple dna strands and genes
• Sex linked genes are traits influenced by genes carried via sex chromosomes (normally x chromosomes because more genes than y)
• Mendel's Rule only applies to autosomal genes
• x chromosome inactivation randomly 'turns off' one x chromosome, inactive chromosome=barr body. Whole chromosome inactivated forever.
• Epistatic: Recessive trait blocks another allele (Ex: Albinism)
• Pedigree is a chart for tracing genes in a family
• Autosomal genes show different patterns on a pedigree than sex linked genes.
• Phenotypes are used to infer genotypes on a pedigree
• Squares= Male; Circles= Female
• Colored in shape= person has trait in question