Heredity - MT3 - Part 2 Flashcards
Who did Mendel interest?
Karl Nageli
- eminent botanist
What did Nageli suggest?
That Mendel try to repeat his work with a different plant - hawkweed
What kind of plant was hawkweed?
Apomictic
Apomictic
Produces seeds without fertilization
Why was Nageli’s suggestion a terrible idea?
Because hawkweed was an apomictic plant
- Mendel genetics is sexual genetics and the plant wouldn’t work in this scenario
What did Nageli say about the cell theory?
That cells come from pre-existing cells
What could Mendel not do?
Repeat his work
- this was a contributing factor that lead him to abandon science
What 2 things did Weismann distinguish between?
- Germ-plasma
2. Somato-plasma
Germ-plasma
The precursor cells of sex cells
- the sex cells come form a group of cells that set aside very early in development
- preserved and not do divide often
What is germ-plasma responsible for?
Gernerational continuity
Somato-plasma
The rest of the cells in the body
- important but not for generational continuity
What did Weismann and Mendel’s theory of inheritance have on common?
It invovled hereditary particles rather than fluids
What does a germ cell have?
Hundreds of complete sets of hereditary particles, passed along form previous generations
What did each cell contain?
Chromosomes that contain genomes going back many generations
Biometrics
Is the application of statistics to biological problems
Who was biometrics pioneered by?
Sir Francis Galton
- cousins of Darwins
What kind of variation did Mendel study?
Discrete (discontinuous) variation
What kind of variation did Galton study?
Quantitative (continuous) variation
What did Galton thing quantitative (continuous) variation to be the key for?
To the study of both hereditary and evolution
- as well important in the study of practical problems of genetics such as increase milk production of cattle or of yields of crops
What did Galton’s law not distinguish between?
Genes and genomes
- no atoms of inheritance
What did Galton want to know?
If prayer had any power
What was Galton considered to be the founder of?
Eugenics
Eugenics
Is the science of improving the human race heritably by selective reproduction
What did Alberta Eugenics Board do?
It didnt selectively breed people, but it supervised the sterilization of mentally handicapped individuals
What was Mendel simply viewed as?
A pea breeder
What were the 3 rediscover?
- Hugo de Vries discovery
- Carl Correns discovery
- Erich von Tschermak discovery
What did de Vries do?
From breeding experiments with poppies he independently derived all of Mendel’s observations and explanation models
- dominant vs recessive
What did de Vries discover?
The re-appearance of the recessive trait in the F2 generation
- 3:1 ratio in the F2 generation
What did de Vries conclude?
That the hereditary units were intracellular pangenes
- probably located on the chromosome
- structural interpretation
What did Correns do?
The same kind of experiments with peas, but with maize
Who did Correns dislike?
de Vries
Why did Correns dislike de Vries?
Because he never credited Mendel in any of his papers
What did von Tschermak do?
He bred peas, using green/yellow cotyledons and round/wrinkle seeds and derived the same 3:1 ratio
- he also did the same backcross as Mendel and got the same results
- friendly to Mendel’s case because his grandfather ruined his life
