Bio 422 Flashcards
Phenotype
outward appearance of an organism
ex: tall, P
Genotype
genetic makeup of an organism
ex: TT or Tt
Dominant
Describes a trait that covers over, or dominates, another form of that trait
Recessive
An allele that is masked when a dominant allele is present
Heterozygous
having two different alleles for a trait
Homozygous
having two identical alleles for a trait
Gene
equivalents of mendel’s trait
Allele
form of a gene
important phenotypic ratios
3:1
1:1
9:3:3:1
1:1:1:1
mendel seven visble features
seed shape, seed color, pod shape, flower color
pod color, flower postion, stem height
true-breeding
term used to describe organisms that produce offspring identical to themselves if allowed to self-pollinate
P1 generation
parental generation
F1 generation
offspring of the P generation
F2 generation
Offspring resulting from interbreeding of the hybrid F1 generation.
Mendel’s experiment
Gregor Mendel cross-pollinated plants that had different traits, and found that they were heritable
Mendel model organism Peas
easy to grow
true breedding strains
controlled matings (self ferlilzation)
observed characteristics with two different forms
grow maturity in one season
Simple Mendelian Inheritance
A single gene with two different alleles
Alleles display a simple dominant/recessive relationship
True (pure) breeding
an organism that always passes on a specific trait to its offspring, which means the trait is homozygous.
reciprocal crosses
a pair of crosses between a male of one strain and a female of another, and vice versa
Mendel three laws
Dominance/recessiveness
Segregation
Independent Assortment
Law of Dominance
When there are two different alleles, one is dominant and other recessive
Law of Segregation
two alleles for each gene are placed in different gametes
Law of Independent Assortment
the inheritance of one gene does not affect the inheritance of another gene.
complete dominance
a relationship in which one allele is completely dominant over another
autosomal
the sex of the parent giving a particular allele doesn’t matter
monohybrid cross
A cross between two individuals, concentrating on only one definable trait