linkage and mapping Flashcards
what does it mean if genes are genetically linked?
the genes are in close proximity to one another on the same chromosome and so they assort together.
define parental type
the offspring which has the same phenotype as the parent - genotype doesn’t matter
define recombinant or non-parental type
mixed phenotype - crossover event happened and offspring does not resemble parent
what is criss-cross inheritance
when the sons look like their mother and the daughters look like their father
when considering genes on the X chromosome, we only look at the _______ offspring
male
crossover events are like __________
accidents
the further apart two genes are, the more ____________ types there will be
recombinant
a chromosome cannot be longer than ______ map units
50
what does the null hypothesis for linkage state?
the genes are not linked and they assort independently. the deviations from expected numbers are due to chance.
what does a p-value of 0.05 mean?
there is a 5% chance that the observed deviation is due to chance
what does a high p-value and a low p-value mean
p-value high: the deviation is insignificant so we cannot reject the null hypothesis
low p-value: the deviation is significant so we reject the null hypothesis. genes are linked
recombinant frequency cannot surpass ___%
50
what are the limitations of two-point crosses?
- it’s difficult to determine the correct order of genes
- not accurate for determining the distance between genes that are far away from each other
what is region I and region II on a chromosome?
region 1: two highest frequencies (not including parent types) that are single crossover recombinants between the two most distance adjacent genes
region II: second two highest frequencies that are single crossover events between two closest adjacent genes
