Additional Factors at a Single Locus Can Affect a Genetic Cross
Additional factors that act on a single gene can alter the expected outcomes that Mendel’s basic principles of inheritance predict. This text provides an overview of exceptions to Mendelian inheritance, including types of dominance (e.g., incomplete dominance and codominance), multiple alleles, pleiotropy, lethal alleles, and penetrance and expressivity.
Topics
- 1:2:1 genotypic ratio
- 1:2:1 phenotypic ratio
- 3:1 phenotypic ratio
- codominance
- complete dominance
- complete penetrance
- dominance relationship
- dominance
- expressivity
- F1 hybrid
- genotype
- genotypic ratio
- Gregor Mendel
- heterozygous
- homozygous
- hybrid
- incomplete dominance
- incomplete penetrance
- inheritance
- invariable expressivity
- law of independent assortment
- law of segregation
- lethal allele
- Mendel
- Mendelian trait
- multiple alleles
- pea plant
- pea seed shape
- penetrance
- phenotype
- phenotypic ratio
- Pisum sativum
- pleiotropy
- simple trait
- single-gene inheritance
- true-breeding parent
- types of dominance
- variable expressivity