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Gregor Mendel
• The study of heredity started with the work of Gregor Mendel and his pea plant garden.
• Gregor Mendel is considered to be the father of genetics.
• Genetics is the study of biological inheritance patterns and variation in organisms.
Who was Gregor Mendel?
Gregor Mendel was born in 1822 in Austria.He grew up on his family’s farm and wasable to learn a lot about flowers and fruittrees. After going to college, he joined a
monastery. At the monastery, he worked inthe garden where he studied how traits were
passed form parent to offspring.
Why??
Mendel noticed that some patterns ofinheritance made sense and others did not. Forexample, Mendel noticed that when he crossed
a purple flowered pea plant with a whiteflowered pea plant, that all of the offspring had
purple flowers. He then noticed that if hecrossed two of these offspring, then one out of
every four offspring had white flowers.Mendel wanted to know why.
What did Mendel Do?
Mendel looked at 7 traits of pea plants.Mendel crossed pea plants with two
different forms of each trait (for example,smooth/wrinkled peas or yellow/green peas)to determine which traits would appear and
how often. Mendel was then able todetermine which of the 7 traits weredominant and which were recessive.
How??
• The flowers of pea plants are self pollinating which means that they contain both male and female reproductive structures.
• Pollen from one flower or plant can fertilize the eggs of the same plant or another plant.
HOW???
Mendel cut off the anthers of one flowerand used the pollen from these anthers tofertilize the stamen on another plant. Forexample, he used the pollen from a plant
that produced wrinkled seeds to fertilize theplant that produced round seeds. The stigma
of the flower actually turns into seeds(peas). These seeds/peas are then planted in
the ground to produce more pea plants.
Steps of Mendel's Experiment
Mendel’s Conclusions
• He came to three important conclusions from these experimental results:1. that the inheritance of each trait is determined by "units" or "factors" that are passed on to descendents unchanged (these units are now called genes ) 2. that an individual inherits one such unit from each parent for each trait 3. that a trait may not show up in an individual but can still be passed on to the next generation.
