Fundamentals of Genetics

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Fundamentals of Genetics
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Gregor Mendel

• The father of modern genetics the study of
  heredity
• Experimented with garden peas in the 1800s
• He produced a hybrid pea plant an organism that
  receives different genetic information from each
  parent - in his experiments
• He looked at only a few different traits, they
  were seed shape, color, pod shape, pod color,
  flower position and height.

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Gregor Mendel

• He took 2 pure bred plants the parent contains
  only one gene for each genetic trait and
  crossed them.
• After performing his experiment he found
• Dominant trait - the trait that is expressed
  was always expressed. Usually shown as a capital
  letter.
• Recessive trait the trait that is only when
  there is two of them- usually shown as a lower
  case letter.

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Vocabulary Words

• Before beginning, a vocabulary word.
• Alleles - different versions for
• the same trait.
• Example T (tall) and t (short) are alleles for
  the
• gene that controls height of the pea plant.
• Homozygous having two (2) of the same alleles
  for the same trait.
• Example TT homozygous dominant
• tt homozygous recessive
• Heterozygous having two (2) different alleles
  for the same trait.
• Example Tt

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More Vocabulary Words

• Genotype the genes that an organism possesses
• Phenotype the way the genes are expressed (how
  the organism looks)
• Can you answer this question?
• How does your genotype control your phenotype.

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Mendels Laws

• 1. Law of Segregation - each pair of alleles
  segregates, or separates during meiosis.
• 2. Law of Dominance An allele that always
  controls a trait is called the dominant allele.
  An allele that is hidden when paired with a
  dominant allele is called a recessive gene

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Mendels Laws

• 3. Law of Independent Assortment the
  association of traits in a parent does not seem
  to matter. Mendel concluded that traits, or
  factors, are inherited independently.