Modification of Mendelian Ratio Flashcards
Most frequently encountered allele in a population, arbitrarily considered as normal.
Wild-type allele
Modification of genetic sequence.
Mutation
Mutation that brought about diminished functionality of the gene.
Loss of function mutation
Eventual loss of function of a gene due to mutation.
Null allele
Increased activity of a gene due to mutation.
Gain of function mutation
Mutation in a gene that does not necessarily altered its activity.
Neutral mutation
Lowercase and italicized (dd)
Recessive allele
Uppercase and italicized (DD)
Dominant allele
Both alleles are DOMINANT thereby expressing 2 distinct gene products.
Heterozygotes
In a population of organisms, the presence of three or more alleles of the same gene.
Multiple alleles
Simplest case of multiple alleles is that which three alternative alleles of one gene exist.
The ABO Blood Group
Discovered ABO Blood Group
Karl Landsteiner
A antigen
A phenotype
B antigen
B phenotype
A and B antigen
AB phenotype
neither antigen
O phenotype
A rare variant of the ABO antigen system in which affected individuals do not have A or B antigens and thus appear to have blood type O, even though their genotype may carry unexpressed alleles for the A and/or B antigen.
The Bombay phenotype
Genetic mutation which might lead to death.
Lethal Alleles
Genes function primarily for the expression/production of substances essential to life.
Lethal Alleles
[3] Mutations in genes that do such may be lethal:
- Heterozygous recessive lethal allele
- Homozygous recessive lethal allele
- Dominant lethal allele
It is defined as the tendency for alleles close together on the same chromosome to be transmitted together as an intact unit through meiosis.
Genetic linkage
The nonreciprocal interaction between nonallelic genes such that one gene influences or interferes with the expression of another gene, leading to a specific phenotype.
Epistasis
Other cases of gene interaction yield novel, or new, phenotypes in the F2 generation, in addition to producing modified dihybrid ratios.
Novel Phenotypes
The lethal mutation is present (mutation that leads to total non-functionality of the gene) but there is another allele that may compensate.
Heterozygous recessive lethal allele
