Mendel

1
Mendels Work

• Principles of Genetic Inheritance

2
Gregor Mendel

• 1851 Began experimenting with pea plants
• 1866 Presented presented a paper describing a
  process for inheritance of characteristics
• 1900 His work is rediscovered and he is
  recognized as the Father of Genetics

3

• Cross-pollination animation

4
(No Transcript)
5
Genes

• A gene is a segment of DNA that codes for a
  specific trait.
• Different forms of a gene are called alleles.
• Individual alleles control the inheritance of
  traits.

6
Alleles

• One allele is inherited from each parent.

7
Alleles

• A dominant allele is one that shows up when it is
  present. (Capital letter C)
• A recessive allele is hidden by a dominant
  allele. It is expressed when both are recessive.
  (lower case letter c)

8

• The genotype is the combination of alleles CC,
  Cc, cc.
• The phenotype is the expression of the alleles
  CC red, Cc red, cc white.

9

• The possible outcomes of a genetic cross are
  shown on a Punnett square.
• The probability of an outcome can be determined
  using a Punnett square.

10

• Whats wrong with this Punnett square?

11

• More complex outcomes can be shown using the
  Punnett square. You will explore this in high
  school biology.

12
Punnett Squares

• Use this link to try different combinations of
  traits. The traits are in English.
• The labels are in Hebrew. Use the left button to
  start the cross. Use the right button to reset
  the square.
• http//zinman.org.il/html/bio/sim/sim.html

13

• Pea Experiment