Gregor Mendel Flashcards
Gregor Mendel
Father of genetics, Austrian Monk
1857
began collecting pure lines of peas
Why did he choose self fertilising peas
So all offspring look like their parent
How many traits did Mendel choose
7
1st trait
Round or wrinkled ripe seed coats(testa)
2nd trait
yellow or green seed interiors(cotyledon-food storage)
3rd trait
purple or white petals
4th trait
Inflated or pinched ripe pods
5th trait
long or short stems
Why peas
self fertilizing
short growth period
produce large number of offspring
Mendel’s Experiment
crossed pure plants with alternative phenotypes for a single trait
Then recorded how many offspring there were of each type(1st generation results)
Allowed them to self-fertilise
GG
homozygous dominant
gg
homozygous recessive
Gg
heterozygous
Findings
again recorded natural of offspring(F2)
did maths,atical analysis
deduced several principle
published paper in scientific journal(1866)
F1 showed
1 of 2 parental traits
f2 generation- missing trait shown
25 percent of time
1st result
Traits are not blended as they are passed from parent to offspring
2nd result
each parent makes equal contribution
3rd result
genes can be carried but not expressed
Law of segregation
Traits are controlled by pairs of factors/genes and separate at gamete formation
Law independant assortment
When 2 or more characteristics are concerned the factors for these enter the gametes independently of each other
