Fundamentals of Genetics

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Fundamentals of Genetics

• Chapter 9

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Background Information

• Genetics is a field in biology that deals with
  how characteristics are transmitted from parents
  to their offspring
• Gregor Johann Mendel founded this study

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Gregor

• In 1842 at the age of 21 Gregor Mendel lived at a
  monastery in Brunn Austria
• In 1851 he moved the U. of Vienna
• He researched heredity (traits transferred from
  parents to offspring)

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Mendel cont.

• He worked primarily with garden peas (Pisum
  sativum)
• He worked with plants that each had two
  contrasting traits

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Copy Traits
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Parts of the Flower
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Pollination

• Mendel controlled how plants were pollinated
• Mendel transferred pollen from the male anther to
  the female stigma

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Self vs. Cross Pollination

• Self- When pollen is transferred to the stigma on
  the same flower Cross- Pollinating the pistil of
  a different flower either on the same plant or a
  different plant

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His Experiments

• 1st started growing plants that were pure for
  each of the 7 traits
• Plants that are pure produce offspring with only
  the same trait
• Eventually he had 14 strains
• Each strain was called the parent generation (P1
  generation)

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Experiments cont.

• He then cross-pollinated plants for the same
  charecteristic (yellow pods with a green pods).
  He did this by dusting the anther on the stigma
  of the other plant

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Experiments cont.

• The offspring plants were called first filial
  generation or the F1 generation
• He recorded what plant was made (green or yellow)
• These new plants self pollinated and made the F2
  generation
• 100s of crosses later and a lot of documentation
  gave us this ?

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Mendels Crosses Data
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Recessive vs. Dominant

• The trait found on the offspring in the 1st
  filial generation was the dominant trait
• The trait that came ¼ of the time on the 2nd
  filial was recessive