Genetic inheritance Flashcards
Phenotype
An organisms outside appearance
Gene
A DNA sequence that codes for a protein that produces a given trait
Heterozygotes
Carrier
Hemizygous
X
Wild-type
default genotype pr phenotype
Mutant
Mutated alleles
Loss of function mutations
recessive. Needs to affect both alleles
Gain of function mutations
Dominant
Pea plant Punett squares results
parents: RR x rr
F1: all Rr
F2: RR, Rr, rr
(1:2:1 genotype) (3:1 phenotype)
Test cross
A dominant phenotype of unknown genotype is crossed with a homozygus recessive organism.
Backcrossing
When a hybrid is crossed back with its parents. Goal: obtain more offspring similar to parent
Dihybrid cross
Looking at two different phenotypes
What is the phenotypic ration when crossing heterozygotes in a dihybrid cross?
9:3:3:1
Complete dominance
One dominant allele masks expression of other
Codominance
Dominant alleles are both expressed
EX) AB bloodtype
Incomplete dominance
When the F1 generation shows a blended phenotype. Intermediate of both parents
Penetrance
Percent of individuals with a given genotype who display the associate phenotype
Expressivity
Severity of phenotype
Autosomal
Non-sex inherited. Affect F and M equally
Sex-linked
sex linked inherited mutation
Law of segregation
allele pairs segregate randomly from each other into gametes
law of independent assortment
Alleles from separate traits are independently inherited
Law of dominance
Recessive alleles will be masked to some degree
Chiasmata
Crossing over points
