Week 3 - Patterns Of Inheritance Flashcards
(20 cards)
Gene
Section of DNA that codes for a particular characteristic
Mongenetic trait
One pair of genes determines a given characteristic
Polygenetic inheritance
More than one pair of genes determine a characteristic
Phenotype
Observable characteristic/expression of a particular genotype
Genotype
Genes responsible for a particular characteristic
Trait
Particular characteristic of an individual (phenotypic expression)
Alleles
Alternate forms of a gene
Homozygous
Pure breeding
Both genes for a characteristic are identical
(TT) or (tt)
Heterozygous
Hybrid
Genes for a characteristic are different
(Tt)
Dominant
Expressed in phenotype
Will mask recessive gene
(T) dominant over (t)
Recessive
Only appears in phenotype when it is homozygous
Monohybrid Cross
Cross between 2 individuals in which only a single pair of characteristics is being studied
Parental Generation (P)
2 parents who are crossed
First Filial Generation (F1)
First offspring which results from cross of 2 parents
Second Filial Generation (F2)
Formed when 2 F1 individuals are cross with one another
Sex chromosomes
Chromosomes which determine sex of offspring
Two types: X and Y
Autosomes
Chromosomes that are the same in both sexes
Not sex chromosomes
Test Cross
Used to determine genotype of an organism
Individual of unknown genotype is crossed with an individual that is homozygous recessive
Incomplete Dominance
Both alleles fully expressed in phenotype of heterozygote
Eg. Red and white snapdragons produce pink offspring
RR offspring=red pigment
WW offspring=no pigment
RW offspring=some red pigment appears pink
Codominance
Pair of alleles equally expressed but not blended in heterozygote
Eg.
Red cattle=red pigment
White cattle=no pigment
Roan cattle=mixture of red hair and hair without pigment
ABO blood grouping
