Mendelian Genetics I

• What is the most reliable way to solve genetic problems?

  Using a Punnett Square
• Why did the fruit flies in Morgan's experiment not follow Mendel's 2nd law of inheritance?

  Linkage and recombination
• What is polygenetic inheritance?

  A type of non-Mendelian inheritance that occurs when multiple genes work together to influence a trait
• What are the key things to note about epistasis

  It's an interraction between alleles of different genes, not alleles of the same geneThe F2 genotype ratios depend on the function of the specific alleles and how the gene products act togetherEpistasis does not disprove Mendel's laws
• What is Mendel's 2nd law of inheritance?

  Independent assortment: During gamete formation, different pairs of alleles segregate independently of each other
• What is Mendel's 1st law of inheritance?

  Segregation: Alleles of each gene segregates during gamete formation and then unite, one from each parent at fertilisation
• Mendel's second principle, that of independent assortment, states that...

  Alleles from two genes have an equal probability of segregating to a gamete.
• What is co-dominance? When both alleles in a heterozygous individual are fully expressed, resulting in a phenotype that shows a combination of both traits.
• What is incomplete dominance?

  Incomplete dominance is a genetic inheritance pattern where the heterozygous phenotype is a blend of the two homozygous phenotypes.
• What is a dominance hierarchy?

  Some traits involve multiple alleles with a ranking of dominance.
• What is pleiotropy?

  Pleiotropy is the phenomenon where a single gene influences multiple traits or phenotypes.