Warm Up

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Warm Up

• Earn 5 extra points on last Fridays test.
• Write the balanced chemical reaction for
  photosynthesis and cellular respiration.
• Include where each reaction takes place and label
  each molecule.

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What Do They Have In Common?
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Genes and Heredity

• McDougall Littel

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Parents and Offspring Are Similar

• You are an individual who has a unique
  combination of characteristics.
• These characteristics are also known as traits.
• Many of your traits may resemble those your
  parents like your hair color, eye color, and
  blood type.
• These characteristics are called inherited traits.

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Parents and Offspring Are Similar.

• Some traits are acquired, not inherited.
• An acquired trait develops during your life.
• Learned behaviors are one type of acquired
• trait.
• Reading
• Writing
• Riding a bike
• Acquired traits cannot be transmitted
  genetically.

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Genes Are On Chromosome Pairs.

• A gene is a unit of heredity that occupies a
  specific location on a chromosome and codes
• for a particular characteristic or trait.
• Heredity is the passing of genes from parents
• to offspring.

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Genes are on Chromosome Pairs

• Cells contain pairs of chromosomes, one from each
  parent.
• The chromosomes in a pair are called homologs.
• They have the same size and shape, and carrying
  genetic information for particular traits.
• The genes code for the expression of traits.

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Genes Are On Chromosome Pairs

• Chromosomes come in pairs.
• The various forms of the same gene are called
  alleles (uh-LEELZ).
• Examples height, eye color, hair color, tongue
  roll.
• Alleles
• AA
• Bb
• Cc
• DD
• ee
• Each member in a pair is called a homolog.

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Each Species has a Certain Number of
Chromosomes.

• Chimpanzees have 24 pairs of chromosomes.
• Fruit flies have 4 pairs of chromosomes.
• Humans have 23 pairs.
• Human chromosomes are numbered 1-22.
• The 23rd pair are the sex chromosomes.

• For a total of 48 chromosomes.
• 8 in all.
• 46 total
• XX - chromosomes for Females.
• XY - for chromosomes Males.

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Gregor Mendel

• Gregor Mendel is the father of genetics.
• He investigated the inheritance of traits among
  pea plants.

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Alleles Interact to Produce Traits.

• Genotype is the name for the genes an organism
  has.
• Your genotype is not always obvious from your
  phenotype.
• Sometimes your genes contain information that is
  not expressed in your phenotype.
• Its what we cant see.

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Alleles Interact to Produce Traits.

• An organisms phenotype describes the actual
  characteristics that can be observed.
• Its what you can see.
• -height
• -size of your feet
• -baldness
• Observable traits and are part of your phenotype.

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Dominant and Recessive Alleles

• A dominant allele is one that is expressed in the
  phenotype.
• -B Brown eyes
• -b Blue eyes
• -The BB and Bb genotype would produce an
  offspring with brown eyes because brown eyes are
  dominant.

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Dominant and Recessive Alleles

• A recessive allele is one that is expressed in
  the phenotype only when two copies of it are
  present on the homologs.
• -b (blue) is recessive
• -bb blue eyes
• Two brown haired parents produce a blonde child.

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Dominant and Recessive Alleles

• If both alleles are the same, the organism is
  homozygous, or purebred, for that trait
• AA, BB, aa, bb
• If the two alleles are different, the organism is
  heterozygous, or hybrid, for that trait.
• Aa, Bb, Cc, Dd, Ee, Ff

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Dominant and Recessive Alleles

• Dominant alleles are always written with a
  capital letter.
• TT, AA, GG, CC, UU
• Recessive alleles are always written with a
  lowercase letter.
• tt, aa, gg, cc, uu

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What Do They Have In Common?
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They Sharethe SameGene Pool