Week 7-8: Mendel and Heredity Flashcards
characteristic
an observable, heritable feature that may vary among individuals
trait
each variant for a characteristic
true breeding
plants that over many generations of self-pollination had produced only the same trait as the parent plant
P generation
true-breeding parent plants at the start of his experiments
hybridization
The mating/crossing of two different true-breeding varieties
F1 generation (first filial)
first generation of plants (the children/offspring of the P generation)
F2 generation (second filial)
F₁ generation to self-fertilize or to only interbreed with other F₁ generation plants
Blending hypothesis (antiquated)
parental traits are blended together to produce offspring that have a mixed/intermediate physical appearance.
alleles
alternative versions of a gene
For example, in pea plants, for the flower color gene there is an allele for purple flowers and an allele for white flowers
homozygous
two alleles for a single gene are identical, as in the case of true-breeding plants
heterozygous
Other times they are two different alleles
Same TRAIT (i.e. height) on both chromosomes of a homologous pair but different ALLELES e.g. tall vs short
Law of segregation
The two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes.
dominant allele
If the two alleles at a locus differ, then one, the dominant allele, determines the organism’s appearance;
recessive allele
has no noticeable effect on the organism’s appearance
genotype
organism’s genetic makeup; includes alleles that may not be physically observable in the organism’s appearance
phenotype
the observable physical expression of the gene,
Punnet square
diagram that visually shows all the
possible genetic outcomes of a
cross.
