Exam 2

• How can the proband be caused?

  a mutation during gamete formation
• What is the proband?

  the individual whose phenotype first brought attention to the family
• What is an example of a pattern a pedigree might reveal?

  if it is due to a dominant or recessive allele
• What is a pedigree?


  family tree with respect to given trait
• What do pedigrees do?

  reveal patterns of inheritance of human traits
• When is null hypothesis accepted?

  p value of or greater than 0.05
• When is the null hypothsis rejected?

  p value is less than 0.05
• A p value greater than or equal to 0.05 means what?

  the observed deviation from the expected results will be obtained by chance alone more than 5% of the time.
• A p value of less than 0.05 means what?

  the observed deviation from expected results will be obtained by chance alone less than 5% of the time
• What is probability value?

  When degrees of freedom is determined, chi-square value can be interpreted in terms of a corresponding probability value
• What does n mean for degrees of freedom?


  number of different categories into which data points may fall (different outcomes)
• Why must degrees of freedom be taken into account ?

  the greater the number of categories, the more deviation is expected as a result of chance
• What is degrees of freedom equal to?

  n=1
• What is the Chi-square an analysis of?

  observed vs. expected deviations
• if a null hypotheis is determined by statistical analysis to be rejected then any observed difference is...

  accepted to not be attributed purel by chance
• if a null hypothesis is determined by statistical analysis to fail to be rejected then any observed difference is...

  accepted to be attributed purely by chance
• A null hypothesis can either be...

  accepted or rejected
• null hypothesis

  assumes data will fit the expected ratio/assumes there is no real difference between measured values and predicted values
• Chance deviation


  chance events are subject to random fluctuations
• Chi-square analysis


  evaluates influence of chance on genetic data
• sum law


  the probability of two (or more) mutually exclusive events occurring is equal to the sum of the events individual probabilities
• product law


  the probability of two (or more) independent events occurring together can be calculated by multiplying the individual probabilities of the events
• Probability


  How likely something is to happen
• What would be some example genotypes for a two character testcross?

  GGWW, GGWw, GgWW, Gg,Ww
• In a two character testcross the individuals express....

  two dominant traits
• In a two character testcross the genotypes are...

  unknown
• What is a testcross for one character a cross between?

  dominant phenotype and homozygous recessive
• What does a testcross for one character determine?

  if an individual displaying a dominant phenotype is homozygous or heterozygous for that trait
• What is a testcross for one character used for?

  to determine an unknown genotype
• What is an easier method to the trihybrid cross?

  fork-line method
• How many boxes does the Punnett square for a trihybrid cross have?

  64
• What is a trihybrid cross?

  segregation and independent assortment applied to three different characters
• Does the monohybrid or dihybrid cross generate a unique F2 generation?

  dihybrid
• What does the dihybrid cross consist of?

  two pairs of contrasting traits
• What can be visualized using a Punnett square?

  genotypes and phenotypes resulting from combining gametes
• What does the Punnett square display?

  all possible random fertilization events
• Who devised the Punnett Square?

  Reginald C. Punnett
• What is it called when F1 individuals self pollinate or cross pollinate with other F1 hybrids?

  F2 generation
• Would the F1 generation be homozygous or heterozygous?

  heterozygous
• What was the hybrid offspring of the P generation called?

  F1 generation