Heredity

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Heredity

• By Mr. Kauffman

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Outline

• What are genes?
• Gregor Mendel
• Where can we find our genes?
• What do our genes do?
• Our Genes
• Genetic Trait Tree
• Where do we get our genes from?
• Inheritance
• Predicting Inheritance
• Modern uses of DNA technology

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What are genes?

• Heredity the passing of genes from parents to
  offspring (children)
• Gene a specific part of DNA that controls a
  hereditary trait
• Hereditary traits characteristics that can be
  passed from parents to their offspring

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Inherited vs. Acquired Characteristics

• Inherited characteristics characteristics that
  are controlled by genes/DNA passed from parents
  to their offspring
• Examples -gt height, natural hair color, eye
  color

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Inherited vs. Acquired Characteristics

• Acquired characteristics characteristics that
  can be developed or altered during a persons
  lifetime
• Examples -gt tattoo, learning to play a sport,
  learning to play a musical instrument

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Gregor Mendel

• Austrian monk
• Considered to be the father of modern Genetics
• Used pea plants to demonstrate how certain
  characteristics were passed through generations
• Seed shape, seed color, flower color, pod shape,
  pod color, and stem height

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Mendels Work
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Where can we find our genes?

• We have 1000s of genes and each one is found at
  a specific location on a specific chromosome
• What does that mean?
• All genes are found in specific places
• Everyone has different combinations of traits,
  but
• The genes for those traits are found on the same
  parts of chromosomes in everyone

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What do our genes do?

• Genes determine the traits that we have
• We are most familiar with physical traits
• So basically our genes determine what we look
  like
• Physical traits are observable characteristics
• Things that we can see
• examples hair color, eye color, tongue rolling,
  ear lobes, hairline

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Genetic Trait Tree

• We are going to be creating a Genetic Trait Tree
  to examine certain characteristics (traits)
  within our class
• For this activity we will be examining 3 traits
• Free or attached ear lobes
• Widows peak
• Tongue rolling

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Our Genes

• How many genes do humans have?
• http//web.ornl.gov/sci/techresources/Human_Genome
  /posters/chromosome/

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Our Genes

• We have 2 copies of each gene (1 from each
  parent)
• Each gene has 2 or more variations for what we
  see
• We can inherit the same or different variations
• examples
• Hair color brown, black, red, blonde
• Tongue rolling can do it, cant do it

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Where do we get our genes from?

• ½ comes from mother
• 23 single chromosomes in the egg cell
• ½ comes from father
• 23 single chromosomes in sperm cell

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Where do we get our genes from?

• When the sperm and egg cells combine they form 1
  cell with 46 single chromosomes (23 pairs).
• All humans have started as 1 cell just like that

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Inheritance

• The characteristics seen in us depend on 2
  things.
• 1. the combination of genes we get from our
  parents
• 2. how those genes interact with each other
• The different variations of genes are called
  alleles
• 2 basic alleles (gene variations)
• Dominant the trait/characteristic that is
  always seen if it is present
• Recessive the trait/characteristic that is only
  seen when the dominant variation is not present

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Dominant and Recessive Traits

• Example of dominant and recessive alleles
• A person can have a widows peak (dominant) or a
  straight hairline (recessive)
• 2 dominant alleles a person with a widows peak
• 1 dominant and 1 recessive allele a person with
  a widows peak
• 2 recessive alleles a person with a straight
  hairline

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Inheritance Terms

• Homozygous Dominant 2 dominant genes
• Homozygous Recessive 2 recessive genes
• Heterozygous 1 dominant and 1 recessive gene

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Predicting Inheritance

• Punnett Square a tool to predict the
  characteristics a child can inherit from its
  parents
• Use the alleles each parent has to determine the
  possible gene combinations that can be passed to
  offspring
• Capital letters dominant allele
• Lowercase letters recessive allele

W dominant
w recessive
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Punnett Square Example

• Example using hairline
• Mother has the following combination Ww
• Father has the following combination ww
• They each pass 1 gene variation (letter) to their
  offspring
• Draw a Punnett Square
• Label sides
• Add parent variations
• Fill in the square

MOTHER
W
w


W w
FATHER
w
w w
w
W w
w w
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Punnett Square Example

• What does this show us?
• Dominant widows peak
• Recessive straight hairline
• Genotype genetic makeup
• 2 of 4 children have Ww and 2 have ww
• Phenotype physical appearance
• 50 chance of having a child with a widows peak
• 50 chance of having a child with straight
  hairline

MOTHER
W
w


W w
FATHER
w
w w
w
W w
w w
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Modern uses of DNA Technology

• Selective Breeding
• Breeding plants or animals for specific traits
  (making them look the way we want)
• Has been used to create all of the different
  breeds of dogs that we currently have
• Bred to make them better hunters, or nicer
  temper, or better for protection

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Modern uses of DNA Technology

• Forensic Science
• DNA Fingerprinting identifying people based on
  their DNA
• What shows on TV have you seen that use this?

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Forensic Science Pictures
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Forensic Science Pictures
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Modern uses of DNA Technology

• Genetic engineering
• Changing the DNA of an organism to alter it in
  some way
• Has been used to alter plants and vegetables
• Grow bigger, faster, in tougher conditions, and
  resistant to insects

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Modern uses of DNA Technology

• Gene Therapy
• A type of genetic engineering in which damaged
  genes are replaced by normal genes

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Genetic Engineering Movies
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Modern Uses of DNA Technology

• Cloning
• Creating an exact copy of an existing organism
• Dolly (a sheep) was the first cloned animal to
  survive the process
• Happened in 1997
• How is it done?
• There are problems with it though

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Cloning
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Cloning Movies
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Cloning Movies
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Cloning Movies