genetics 2 Flashcards
1
Q
what were the details of Mendel’s hybridization experiments?
A
- took 8 years to breed pure strains of pea plants
- had 22 varieties and 7 pairs of traits (dominant and recessive)
- cross fertilized between varieties
2
Q
What were the results of Mendel’s hybridization experiments?
A
- saw that recessive traits disappeared in the hybrid generation and reappeared in the next generation
- saw discontinuous evolution, that hybrid individuals were not always stable
- seen as the law of segregation
- also saw that D/r trait pairs acted independently (traits don’t influence the inheritance of another)
3
Q
what were three cited reasons why Mendel’s work was neglected during his life?
A
- was published in a semi-obscure journal (actually was a fairly known journal at the time)
- Paper was atheoretical (Mendel did not set his work into context of a general theory)
- both the study system (peas) and trait (colour) were viewed as unimportant
4
Q
Who was von Nageli? How did he influence some of Mendel’s work (negatively)
A
- Botanist who was an expert on hybridization
- he actively was pursuing a theory of inheritance
- told Mendel to work on Hieracium, but when Mendel tried to replicate his work he couldnt
- this is because Hieracium often undergoes parthenogenesis
5
Q
what were some issues with Mendels tables?
A
- wrote homozygous as a/A
- wrote that Aa was hybrid individuals
- never implied pairs of ‘particles’ (alleles)
6
Q
How did theories of inheritance pre 1900’s vary?
A
- discrete vs continuous variation and evolution
- where particles of inheritance came from
- structure of particles
7
Q
who were the individuals who ‘rediscovered’ Mendels 3:1 ratio?
A
- Hug de Vries
- Carl Correns
- Erik von Tschermak
8
Q
who was nettie stevens?
A
- worked with Thomas Hunt Morgan, never credited for her work with him
- her research showed chromosomes contained inherited information
- worked on sex determination in insects
