Mendel: Fundamentals of Genetics

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MendelFundamentals of Genetics
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Gregor MendelFather of Genetics

• 1842 age of 21entered Austrian monasteryjob
  was to tend to the garden.
• 1851entered University of Viennastudied math
  and science. Focused on statistics.
• After college, returned to the monastery and
  taught high school as well as tending to the
  garden.

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• Mendel worked with garden pea plants and how they
  passed their physical characteristics (traits)
  from one generation to the next.what we call
  heredity.
• Mendel observed each physical trait had two
• optionsexample a pea plant can be tall or
  short.
• He called the options factors, we now
• call them alleles. Mendel reasoned each
• trait had two alleles.

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• Other traits of pea plants
• that Mendel observed

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• Mendels Experiments
• -Worked with pure plants, meaning always
  producing offspring with the same trait.
• -Homozygous
• -Parental generation P1 generation.
• -Offspring of the P1 generation F1 generation.
  
• -Offspring of the F1 generation F2 generation

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What Mendel observed
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Mendels Findings

• Mendels Rule of Dominance
• -Mendel concluded that one allele in a pair may
  prevent the other from physically appearing. He
  called this the dominant factor.
• -The allele that did not appear but appeared
  later was called the recessive allele.

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• Mendels Law of Segregation
• -Mendel concluded that alleles separate during
  the formation of reproductive cells (Meiosis).
• What this means each gamete produced during
  Meiosis only receives one allele of the pair
  during gamete formation.
• Therefore, When the gametes (sperm egg) combine
  during fertilization, the offspring have two
  alleles controlling a specific trait.

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• Law of Independent Assortment
• -Mendel crossed plants that differed in two
  traits. For example, flower color and seed
  color. He concluded that the alleles for
  different traits are not connected and are
  distributed to gametes independently.
• What this means an organism can be dominant for
  one trait and recessive for another trait.

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• What Mendel didnt realize was, what was the
  mechanism for passing traits from one generation
  to the next?

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Chromosomes Genes

• Genes- segment of DNA on a
• chromosome that controls a
• particular trait.
• Different forms of genes are called alleles.
• Letters are used to designate alleles.
• Capital letters dominant alleles (G, T, H)
• Lower case letters recessive alleles (g, t, h)

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• Homozygous- both alleles of a pair are alike.
• HH or hh
• (Homozygous dominant or homozygous recessive)
• Heterozygous- alleles of a pair are different.
• Hh

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• Genotype- genetic makeup of an organism.
  Consists of the alleles that an organism inherits
  from its parents. For example HH, Hh, or hh.
• Phenotype- the physical appearance of an
  organism. (Example- purple flowers.)