Unit 5 Genetics Flashcards
Trait
Each variant for a character
True-breeding
Over many generations, it had produced only the same variety as the parent
Hybridization
Mating of two true-breeding parents with at least one differing characteristic.
Allele
Alternative versions of a gene
Law of segregation
States that the two alleles for a heritable character separate from each other during gamete formation and end up in different gametes
Phenotype
An organisms appearance or observable traits
Genotype
An organisms genetic makeup
Testcross
Breeding an organism of unknown genotype with a recessive homozygote
Monohybrid Cross
Cross of two heterozygotes (Rr)
Dihybrid Cross
A cross between two individuals, concentrating on two definable traits
Law of Independent Assortment
States that each pair of alleles segregates independently of each other pair of alleles during gamete formation
Multiplication Rule
States that to determine the probability, we multiple the probability of one event by the probability of the other event
Addition Rule
States that the probability that any one of two or more mutually exclusive events will occur is calculated by adding their individual probabilities
Complete dominance
The offspring always looked like one of the two parental variety because one allele in the pair showed __________
Incomplete dominance
Three or more potential varieties from crossing two parents
Co-dominance
Two alleles each affect the phenotype in separate, distinguishable ways
Pleiotropy
Most genes have multiple phenotypic effects called…
Epistasis
the phenotypic expression of a gene a one locus alters that of a gene at a second locus
Polygenic Inheritance
An additive effect of two or more genes on a single phenotypic character
Carrier
Heterozygous person can transmit the recessive allele to their offspring without themselves having the trait
Gametes
reproductive cells; egg and sperm
homologous chromosomes
Chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis.
Pedigree
A diagram that shows the occurrence of a genetic trait in several generations of a family.
Punnett Square
A chart that shows all the possible combinations of alleles that can result from a genetic cross
wildtype allele
most common allele in a population
wildtype phenotype
most common phenotype
dominant allele
an allele that is fully expressed in the phenotype of a heterozygote
recessive allele
An allele whose phenotypic effect is not observed in a heterozygote.
Heterozygous
having two different alleles for a trait
Homozygous
having two identical alleles for a trait
F1 generation
offspring of the P generation
P generation
Parental generation, the first two individuals that mate in a genetic cross
F2 generation
The offspring of the F 1 generation
sex-linked traits
A trait associated with a gene that is carried only by the male or female parent.
Recombination
the genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division
crossing over
exchange of genetic material between homologous chromosomes during prophase I of meiosis
