Genetics

the scientific study of heredity

any characteristic that can be passed from parents to offspring

and organism that receives different genetic information for a trait from each parent; any organism that has one dominant gene and one recessive

any organism that receives the same genetic information for a trait from each parent; any organism that has either two dominant or two recessive genes

the trait that shows in a hybrid

the trait that does not show in a hybrid

having all dominant genes for a trait

having all recessive genes for a trait

having dominant and recessive genes for a trait

different versions of a gene for the same trait

the type of genes an organism has

the organism’s physical appearance

the inheritance of one gene at a time

.can be grown in a small area
.produce lots of offspring
.can be artificially cross-pollinated

.in a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation
.all the offspring will be heterozygous and express only one dominant trait
.ex) RR x rr = Rr

.during the formation of gametes, the two alleles responsible for a trait separate from each other
.alleles for a trait are then recombined at fertilization, producing the genotype for the traits of the offspring

.alleles for different traits are distributed to sex cells (and offspring) independently of one another
.this law can be illustrated using dihybrid crosses

alleles for these traits are the X chromosome only, not the Y

a relationship in which one allele is completely dominant over another

neither allele is dominant. the two forms of the trait blend into a 3rd form in the heterozygote

both forms of trait show; both alleles are dominant

recessive-complete dominance
red + white = pink- incomplete dominance
red + white = red and white- co-dominance

.traits controlled by more than one gene (more that one pair of alleles)
.these traits show a wide range in different forms
ex) height, skin color, intelligence
.environment has an influence-multifactorial