By: Kristin Hare and Annah Hoffner

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Mendel and His Peas
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• By Kristin Hare and Annah Hoffner

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INTRODUCTION

• Heredity, or the passing of traits from parents
  to offspring, is more complicated than you might
  think.

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Gregor Mendel

• Gregor Mendel was born is Heinzendorf, Austria in
  1822 on a farm where he learned about flowers and
  fruit trees.
• When he was 21 he entered a monastery.
• The monks taught science and performed many
  scientific experiments.
• Mendel discovered the principles of heredity in
  the monastery garden.

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Unraveling the Mystery

• From working with plants, Mendel knew that the
  patterns of inheritance were not always clear.
• For example, sometimes a trait that appeared in
  one generation (parents) was not present in the
  next generation (offspring).
• Mendel decided to study garden peas to learn what
  caused the pattern of the peas in each generation.

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Why PEAS?

• Pea plants grow quickly (in a garden).
• Pea plants are cheap.
• Many different kinds (of traits or
  characteristics).
• No ethical questions.
• Can self-pollinate.

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Self-Pollinating Peas

• A self-pollinating plant has both male (pollen)
  and female (ovule) reproductive structures.
• Because the peas were self-pollinating, Mendel
  was able to grow a true-breeding plant.

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True - Breeding Plant

• When a true-breeding plant self- pollinates, the
  offspring will have the same trait as the parent.
• For example, a true-breeding plant with purple
  flowers will always have offspring with purple
  flowers.

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Characteristics

• A characteristic is a feature that has different
  forms in a population.
• Mendel studied only one characteristic at a time.
• The different forms (such as round peas and
  wrinkled peas) are called TRAITS.

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Mix and Match

• Mendel decided to see what would happen if he
  crossed two plants that had different traits of a
  single characteristic.
• He removed the anthers of purple flowered plant
  so that it could not self-pollinate, and
  cross-pollinated it with a white flowered plant.

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Mendels Experiments
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Traits

• A dominant trait is the trait observed in the
  first generation when parents that have different
  traits are bred.
• A recessive trait is a trait that reappears in
  the second generation (after disappearing in the
  first generation) when parents with different
  traits are bred.
• To recede means to go away or back off.
• The hidden trait.

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TRAITS
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D
R
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Gone but Not Forgotten

• In 1865, Mendel published his findings, however,
  it wasnt until 30 years after he had died that
  his work was widely recognized.

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The End