Key Terms Chapter 8
Terms
undefined, object
copy deck
- hereditary
- transmission of genetic traits from parent to offspring
- genetics
- study of hereditary
- monohybrid cross
- cross involving one pair of contrasting traits
- true-breeding
- displaying only one form of a particular trait in offspring
- P generation
- (parental generation) the first two individuals that mate in a genetic cross
- F1 generation
- the first offspring from a cross of two varieties in the parental generation
- F2 generation
- the offspring from crosses among individuals of the F1 generation
- allele
- an alternative form of a gene
- dominant
- genetic trait that is expressed when its allele in homozygous or heterozygous
- recessive
- genetic trait that is not expressed when the contrasting form of the trait is present
- homozygous
- refers to an individual with two identical alleles for a trait
- heterozygous
- refers to an individual with two different alleles for a trait
- genotype
- the genetic makeup of an organism as indicated by its set of alleles
- phenotype
- observable characteristics of an organism
- law of segregation
- first law of heredity stating that pairs of alleles for a trait separate when gametes are formed
- law of independant assortment
- second law of heredity stating that pairs of genes separate independently of one another in meiosis
- Punnett square
- diagram used by biologists to predict the probable outcome of a genetic cross
- test cross
- a genetic cross of an individual whose phenotype is dominant but whose genotype is unknown, with a homozygous recessive individual
- probabliity
- the likelihood that a specific even will occur
- pedigree
- family history that shoes how a trait is inherited over several generations
- sex linked trait
- a trait that is determined by a gene found on the X chromosome
- polygenic trait
- characteristic of an organism that is influenced by several genes
- incomplete dominance
- condition in which a trait in an individual is intermediate between the phenotype of its parents
- codominance
- condition in which both alleles for a gene are expressed when present
- multiple alleles
- the existence of more that two alleles (versions of a gene) for a genetic trait