Mendel’s Experiments
Genetics: the study of hereditary
Heredity: the passing of traits
from parents to offspring.
Genetics was founded by Gregor
Mendel.
List some information about
Mendel (could also read from text).
http://www.youtube.com/watch?v=vIrrtM47Wio
Mendel’s Experiments
• Mendel noticed that there were several different traits in
pea plants that were passed from parent to offspring.
• Each trait is controlled by a gene
– Gene: a segment of DNA that determines a trait (makes
a protein)
– Allele: An alternate form of a gene.
Mendel’s Experiments
Experiment 1
• Mendel wanted to know what would happen if he crosspollinated a true-breeding tall plant with a true-breeding
short plant.
– True-breeding: the plant was created through selfpollination.
– A true-breeding short plant will always produce short
offspring through self pollination.
– What did Mendel
expect to see in the P
generation cross?
Mendel’s Experiments
• Principle of Dominance: • Dominant Alleles:
– The trait is always
some alleles are
expressed if a dominant
dominant and others are
allele is present.
recessive.
– Abbreviated with a
capital letter (T).
• Recessive Allele:
– Trait is only expressed if
there is no dominant
allele present.
– Abbreviated with a
lower case letter (t).