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Published byEmmeline Cole Modified over 9 years ago
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Do Now 12/14/15 Get out the “Genetic Traits” activity from Friday and work on that for about 10 minutes Homework: Finish Genetic Traits activity
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Guinea Pig Finalists were, in order – Taco (23) – Oreo (20) – Plutonium (Pluto) (12)
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DNA and Genetics
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Who are you? This question can be answered many ways… Personality traits – Kindness – Vegetarian or Carnivore – Competitiveness ***Traits you can control
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Who are you? This question can be answered many ways… Physical Traits – Height – Eye color – Hair color and texture – Foot size – Bone strength ***Traits you can’t control
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Who are you? DNA controls your inherited traits DNA is given to each new daughter cell in the cell cycle to ensure that genetic information and traits are maintained.
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DNA Structure DNA double helix DNA backbone Bases DNA has a structure we call a double helix
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DNA Double Helix
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Bases are Important! There are four bases: The order of these bases along a strand of DNA codes for your genes. Adenine A Thymine T Cytosine C Guanine G
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DNA is Picky Just like a model wearing a suit jacket with suit pants, or a t-shirt with blue jeans, A only pairs with T and G only pairs with C. You put air (A) in your tires (T) You put gas (G) in your car (C)
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DNA Replication DNA will unzip, and allow for 2 new copies of DNA to be made. How? – Uses the base pairs to see what piece needs to be added to the DNA next
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DNA Replication https://www.youtube.co m/watch?v=zdDkiRw1Pd U https://www.youtube.co m/watch?v=zdDkiRw1Pd U
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Grasshoppers Walter Sutton studied sex cells in grasshoppers – Found 24 chromosomes in “body cells” – Found 12 chromosomes in “sex cells” – What???
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Sex Cells Humans have 46 chromosomes in body cells Where does your DNA come from? – Half from Mom, half from Dad How many chromosomes in sex cells? 23 Body cells have 23 pairs (46 total) of chromosomes – Why pairs?
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Meiosis Process of creating sex cells from a body cell One cell will undergo division twice, creating 4 sex cells After two cell divisions, four cells with 23 chromosomes each are formed.
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Do Now 12/15/15 Submit activity in the box by the window How do base pairs work together to ensure that DNA is replicated properly? Homework: None
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Twins Identical twins are born with the same DNA – Fertilized egg will split Fraternal twins are born with separate DNA – Two different eggs fertilized by two different sperm – Much like regular brothers and sisters
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Twins Identical twins later in life do not have the same DNA – How? Studies found that certain things can change the DNA over extended time – Diet and smoking are thought to change DNA – Mutations do change DNA
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Genes Genes are found on chromosomes Genes have multiple alleles – Dominant and recessive Each body cell has about 35,000 genes
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Protein synthesis The order of the bases in DNA controls what protein is to be made – DNA is the instructions for making proteins Need a messenger to carry the instructions!
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Protein Synthesis mRNA is the messenger that carries the “code” to the _______________? – Ribosomes
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Protein Synthesis mRNA gives the ribosomes the instructions, and the proteins are made from chains of amino acids! Video – https://www.youtube.com/watch?v=gG7uCskUOrA https://www.youtube.com/watch?v=gG7uCskUOrA
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Mutations A mutation affects the way that proteins are made, which changes a trait about a person – Substituting a base pair – Deleting a base pair – Adding a base pair
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Mutations
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Mutations can be good and bad – Mutation that turns a rabbit white Help or hurt survival chances in a snowy area? Help or hurt survival chances in a wooded area? – Mutation that increases resistance to bacteria Help or hurt survival chances?
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Do Now 12/18/15 Trace the order of steps in DNA replication OR Trace the order of steps in mRNA production Finish “Discovering DNA Structure” Updated study guide
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Additional Terms Heredity – The passing of traits from parent to offspring Dominant – Only one allele needs to be present for trait to appear Recessive – Two alleles need to be present for trait to appear
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DNA Replication DNA will unzip, and allow for 2 new copies of DNA to be made. How? – Uses the base pairs to see what piece needs to be added to the DNA next
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DNA Replication https://www.youtube.co m/watch?v=zdDkiRw1Pd U https://www.youtube.co m/watch?v=zdDkiRw1Pd U
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Protein Synthesis mRNA is the messenger that carries the “code” to the _______________? – Ribosomes
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Protein Synthesis mRNA gives the ribosomes the instructions, and the proteins are made from chains of amino acids! Video – https://www.youtube.com/watch?v=gG7uCskUOrA https://www.youtube.com/watch?v=gG7uCskUOrA
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DNA And mRNA Comparison Both produce genetic material Both read the existing base pairs to determine the sequence of the new strand(s) Both happen inside the nucleus
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Contrast DNA Replication – Produces 2 new strands (DNA) – Unzips the entire molecule – DNA cannot leave the nucleus mRNA Production – Produces 1 new strand (RNA) – Only opens the molecule at the bubble – RNA can leave the nucleus
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Mutation Ripple effect change in order of bases in DNA → change in order of bases in mRNA → change in protein produced → change in one of your traits
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