Chapter 5 Patterns of Inheritance (Defs.) Flashcards
Organisms that exhibit the same traits, generation after generation.
True breeding
In breeding, the organisms initially crossed and are typically true breeding.
P generation or parental
The offspring of a cross of the P generation.
F1 generation or first filial
A cross of two individuals that differ by one trait. Only one trait is monitored in the cross.
Monohybrid cross
The offspring of a cross between the F1 generation.
F2 generation or second filial
The form of a trait that always appears when an individual has an allele for it.
Dominant
The form of a trait that only appears when an individual has two alleles for it.
Recessive
Traits are determined by pairs of alleles that segregate during meiosis so that each gamete receives one allele.
Law of segregation
The combination of alleles for any given trait, or the organism’s entire genetic make-up.
Genotype
The physical and physiological traits of an organism.
Phenotype
An organism that has two identical alleles of a gene.
Homozygous
An organism that has two different alleles of a gene.
Heterozygous
A cross between a parent of unknown genotype and a homozygous recessive parent.
Test cross
A cross of two individuals that differ in two traits due to two different genes.
Dihybrid cross
During gamete formation, the two alleles for one gene segregate or assort independently of the alleles for other genes.
Law of independent assortment
Traits determined by genes are inherited through the movement of chromosomes during meiosis.
Chromosome theory of inheritance
A flowchart that uses symbols to show the inheritance patterns of traits in a family over many generations.
Pedigree
A health-care professional with specialized training in medical genetics and counselling.
Genetic counsellor
A technique aimed at treating genetic disorders by introducing the correct form of the defective gene into a patient’s genome.
Gene therapy
