moon 2+ primer Flashcards
what was the blending theory? what does it predict?
traits of parents get mixed like fluid in the offspring, resulting into new traits that resembles parents
prediction: If blended like fluid, parent’s traits are lost in the offspring and cannot be recovere
what did mendel do?
Mendel was able to controlthe crosses between different pure bred pea plants.
whats isogenic?
pure bred
progeny?
offspring
how did mendel disprove the blending theory?
when crossing purple plant with white plant, they didnt blend with each other, the progeny showed the dominant phenotype
whats mendel’s first experiment?
crossing two isogenic pea plants (one purple and one white)
what was the F1 of mendel’s first experiment? what did he do with this generation and what does this say about the blending theory?
what does this experiment suggest?
the F1 was purple heterozygous flowers
self-pollination experiment (monohybrid cross): disproves the blending theory, as the result of this was both purple and white flowers (shows that there is recovery of parental traits)
This also suggests that the “element” responsible for the flower color (trait/phenotype) works like particles, not like fluid, not only maintained from one generation to the next but can be separate
what is mendel’s model/hypothesis?
There are two copies of the “element” (associated with a trait/phenotype) that are inherited from the parents, but only one of the two is visible (dominant/recessive)
Only one of the two is transmitted to the next generation
what is the resulting ratio of the monohybrid cross?
3:1 (3 contain at least one dominant allele)
why did mendel’s experiments work?
Traits affected by only one gene. Many traits (people’s height) are affected by multiple genes
Pure genetic background and ability to cross-or self-pollinate (ability to control cross/mating).
Ability to obtain a large number of progeny
why is the ability to obtain a large number of progeny important?
-low prob events can happen at any time during data collection
-a large sample size helps to determine precise data
-a large sample size reduces the variability betwen experiments
true or false, all traits determined by a single gene
false, some like height determined by multiple genes
during meiosis, how many gametes does a A/a cell produce
4 gametes, same ratio of A to a
only one gets transmitted to the offspring during self pollination
whats a monohybrid?
heterozygote of a gene ex: purple plant that has both white and purple gene
whats a monohybrid cross?
the crossing of 2 individuals that are heterozygous for the same gene
whats a test cross? what is it useful for determining?
the cross of an individual to a fully recessive individual
Testcross is very useful for determining the genotype a testee.
why are loss of function mutations often recessive?
Loss of function mutations (molecular term) are often recessive(phenotype) because a single wild-type copy of the gene can often provide necessary functions for the organism.
what does haplosufficient mean
as long as have one functional copy, mutation does not manifest
what does cystic fibrosis do? what is it caused by?
-Cystic fibrosis affects the cells that produce mucus, sweat and digestive juices such as the lung
-Caused by mutation in the Cystic Fibrosis Transmembrane Receptor (CFTR gene)
why do two carrier parents of CF have a 1 in 4 chance of having a child with CF?
cause CF is a haplosufficient gene
why is the prevalence of CF in canada around 1/3600 when 1/30 people is a carrier?
