topic 3 - mendelian genetics

true breeding

organisms that produce offspring of the same variety over many generations of self-pollination

P generation

true breeding parental generation

F1 generation (first filial)

hybrid offspring of P generation that show the dominant phenotype only

F2 generation (second filial)

offspring of the F1 generation

Punnet squares

diagrams used to predict allele combinations of offspring from a cross with known genotypes

homozygous

an organism that has identical alleles for a trait

heterozygous

an organism that has two different alleles for a gene

genotype

genetic makeup (alleles) of an organism

phenotype

an organisms appearance which is determined by genotype

dominant

the trait that is "stronger" and shows up when the organism heterozygous

recessive

the trait that is "weaker" and is less likely to be a phenotype

alleles

alternative versions of a gene

law of segregation

each gamete for the P generation will contain one allele for flower color

Law of independent assortment

genes for one traits re not inherited with genes of another trait (only applies to genes located on different chromosomes aka not homologous or genes that are very far apart and dont cross over)

monohybrid crosses

a cross between F1 hybrids that produce a 3:1 ratio

dihybrid crosses

a cross between F1 double hybrids that produce a 9:3:3:1 ratio

multiplication rule

probability that two or more independent events will occur at the same time

addition rule

probability that two or more mutually exclusive events will occur

pedigrees

family trees that give a visual representation of inheritance patterns of traits