Final Exam Genetics Flashcards
(155 cards)
Heritable alterations in DNA sequence
Mutations
Locations on a chromosome
Loci
An individual with two different alleles at the same locus is
Heterozygous
For complete dominance the phenotype seen in a heterozygous individual is the result of
Dominant allele
And allele who’s phenotype is not expressed in a heterozygote
Recessive allele
A cross between true breeding parents that differ at only one trait is a
Mono hybrid cross 3 to 1
Cross between parents that differ into traits 9:3:3:1
Dihybrid cross
Used to determine the genotype of one showing a dominant phenotype by mating with individual showing recessive phenotype. 1:1 or all dominant.
Also, a cross between an individual of known genotype to a homozygous recessive individual.
Test cross
Cross an F1 to an individual with an identical genotype to the parent or the actual parent
Back cross
1:2:1
Incomplete dominance. When an F1 hybrid does not resemble either true breeding parent. Intermediate phenotype where both alleles contribute to the phenotype. Pink flowers.
AaxAa
3:1
Complete dominance. AaxAa
9:3:4 AaBb x AaBb
Recessive epistasis. Case of epistasis in which the epistatic allele is recessive. labs. When the presence of two recessive alleles at one gene mask the effects of the alleles at a second Jean.
The effects of a dominant allele at one gene hide the effects of the allele at another Gene
Dominant epistasis.
9:7 AaBb x AaBb at least one dominant allele is necessary, genes working in tandem to produce a particular trait. Purple flowers in sweet peas A-B-
Complementary Gene action
Both traits show up equally in the heterozygote in the F1, in the in the F2 1:2:1. Blood group alleles (a plus B sugars) AB blood type
Codominance
Phenomenon in which a single gene determines a number of distinct and seemingly unrelated characteristics.
Plieotropy
Alternate forms of a gene are called
Alleles
Occurs in individuals who have inherited two recessive allele of the H Jean and do not produce the H carbohydrate that is precursor to A and B antigens. They may possess either or both alleles but are unable to express them. Looks type O. Recessive epistasis.
Bombay phenotype
A trait determined by more than one gene, or a gene and the environment
Multi-factorial
Phenomenon in which a single gene determines A number of distinct and seemingly unrelated characteristics. More than one effect.
Plieotropy
Indicates how many members of a population with a particular genotype show expected phenotype.
Percent penetrance
The degree or intensity with which a particular genotype is expressed
Expressivity
Process in which heterozygosity for loss of function mutant recessive allele for two different genes that affects the same pathway produces normal phenotype
Complementation
Condition in females caused by the presence of only one X chromosome
Turner syndrome