Bell Work: 1/24/12

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Bell Work 1/24/12

• Based on the figure to the left, which of the
  following statements best describes
  cross-pollination?
• A The stigma comes in contact with flowers from
  another plant.
• B Pollen from the anther travels to the stigma of
  the same flower.
• C Pollen from the anther travels to the ovule of
  a different flower.
• D Wind transfers pollen from other plants,
  delivering it to the stigma.

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Challenge Question

• During pollination, what determines the
  characteristics (type, color, size, etc.) of the
  new flower that will be produced from the seeds?

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Objectives

• Describe the relationship between genes,
  chromosomes, and inherited traits (SPI 0707.4.3)

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Cells

• What is the control center of both the plant and
  animal cell?
• nucleus

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Nucleus

• The nucleus is a large organelle in a
  eukaryotic cell that contains chromosomes.
• What part of the school are the chromosomes like?
• Chromosomes are made up of protein and DNA.
• The proteins carry out all the functions and
  characteristics of living organisms, such as
  carrying substances, sending messages,
  protecting the body.
• DNA, or deoxyribonucleic acid, is genetic
  material that determines a plant or an animal's
  inherited traits.
• Genes are sections of DNA that give instructions
  for inherited traits, which are passed from one
  generation to the next.
• Traits are the different forms of
  characteristics, such as purple petals or brown
  hair, that plants and animals have.

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Relationship among chromosomes, DNA, genes...
Nucleus contains chromosomes
Chromosomes are made of DNA ( proteins)
Sections of DNA are called genes.
Genes are sets of instructions for inherited
traits
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Brain Pop
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DNA

• A strand of DNA looks like a twisted ladder.
• This shape is known as a double helix.

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DNA Structure

• DNA is made of nucleotides.
• A nucleotide consists of a sugar, a phosphate,
  and a base.
• Four types of nucleotides
• Sides or backbone phosphate sugar
• Rungs of the ladder pair of bases

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Making Copies of DNA

• The pairing of bases allows the cell to
  replicate, or make copies of, DNA.
• Each base always bonds with only one other base.
• Adenine (A) gt Thymine (T)
• Guanine (G) Cytosine (C)

The sequence CGAC will bond with what?
Sequence GCTG
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How When Copies are Made

• During replication, a DNA molecule is split down
  the middle, where the bases meet.
• The bases on each side of the molecule are used
  as a pattern for a new strand.
• DNA is copied every time a cell divides.
• The job of unwinding, copying, and re-winding the
  DNA is done by the proteins within a cell.

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How DNA WorksUse pgs. 134-135 to create a flow
chart that explains how DNA works.
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(No Transcript)
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3-2-1

• 3 things you learned today
• 2 questions you have
• 1 way this relates to your daily life

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Changes in Genes

• Check out pg. 138 140!
• Changes in the number, type, or order of bases on
  a piece of DNA are known as mutations.
• Sometimes bases are left out, extras are added,
  or the most common, the wrong base is used.
• Consequences of Mutations
• improved trait, no change, harmful trait
• Most of the time proteins detect an error and fix
  it.
• Mutagens, like radiation, can cause mutations in
  DNA.
• When scientists manipulate or change individual
  genes within organisms it is called genetic
  engineering.
• DNA fingerprinting identifies the unique patterns
  in an individuals DNA.
• A clone is an exact copy of another organisms
  genes.

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DNA Drawing

• Draw a portion of a DNA strand.
• You must show the following
• Double helix structure
• Phosphate sugar backbone
• Paired bases in the middle (must be correctly
  bonded base pairs)

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Paper DNA

• Step 1 label the bases on the paper model with
  A, T, G, or C from the bottom to the top. Color
  code the boxes lightly with colored pencil, using
  the DNA guide on the board.
• Step 2 Unzip the paper model by cutting it in
  half vertically and glue the pieces in the
  correct location on your worksheet so the bases
  match up correctly.

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Step 4 Have me check your work build a DNA
model!
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3-2-1

• 3 things you learned today
• 2 questions you have
• 1 way this relates to your daily life