Transcript Mr. Altorfer Science

Mr. Altorfer
Science
Heredity
Section 1
Mendel and His Peas
Pages 114 to 117
• What you will learn: (our objectives)
– Explain the relationship between traits and
heredity.
– Describe the experiments of Gregor Mendel.
– Explain the difference between dominant and
recessive traits.
• Heredity- The passing of genetic traits
from parent to offspring.
– Why do you have brown eyes while both your
parents have blue eyes?
– Why are you the only left handed person in
your family?
– Heredity! That’s why!
Who Was Gregor Mendel?
• Gregor Mendel– Born in 1822
– He became a monk (lived in a monastery)
– He studied heredity by working with pea
plants.
One of my heroes!
A pea plant
Unraveling the Mystery
• Why did Mendel use pea plants?
– Pea plants can self pollinate.
– Peas can also pollinate other pea plants.
Characteristics vs. Traits
• Characteristics- A feature that has
different forms in a population or a group.
– Eye Color, Hair Color
• Traits- Different forms of a characteristic.
– Blue Eyes or Brown Eyes, Red Hair or Brown
Hair
• What traits does this cat have?
– Eye Color:
– Hair Color:
Mendel’s Experiments
• Dominant Trait- The trait observed in the
first generation when parents that have
different traits are bred.
• Recessive Trait- A trait that reappears in
the second generation after disappearing
in the first generation when parents with
different traits are bred.
Ratio’s and Mendel’s Experiments