Bell Work: 2/11/14 Create the chart below and fill out as part of the Mitosis vs. Meiosis notes (2nd page) for BW. Write

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Bell Work 2/11/14 Create the chart below and
fill out as part of the Mitosis vs. Meiosis notes
(2nd page) for BW. Write Compare Contrast on
your BW sheet.
Meiosis
Mitosis
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Mitosis
Meiosis

• Both are processes of cell division
• Both reproduce new cells
• Both go through Interphase, Prophase, Metaphase,
  Anaphase, Telophase, Cytokinesis

• Asexual cell reproduction (only one parent cell
  is needed)
• Produces an exact copy of itself with 46
  chromosomes
• Reproduces two new cells
• Somatic cells body cells (skin cells, blood
  cells, bone cells, muscle cells)

• Sexual cell reproduction (two parent cells are
  needed)
• Produces cells with half as many chromosomes (23)
• Reproduces four new cells
• Sex cells (sperm egg)

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Objectives

• Describe the relationship among genes,
  chromosomes, and inherited traits. (SPI
  0707.4.3)
• Interpret a Punnett square to predict possible
  genetic combinations passed from parents to
  offspring during sexual reproduction.
  (SPI0707.4.4)

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62. Heredity You will need 3 pages
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Heredity

• Why dont you look like a rhinoceros?
• The answer to this question seems simple Neither
  of your parents is a rhinoceros.
• But there is more to this answer than meets the
  eye.
• As it turns out, heredity, or the passing of
  traits from parents to offspring, is more
  complicated than you might think.
• For example, you may have curly hair, while both
  of your parents have straight hair. You might
  have blue eyes while both of your parents have
  brown eyes.
• How does this happen?

THINK. PAIR. SHARE.
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Who was Gregor Mendel?

• Read pg. 100
• Who Was Gregor Mendel?
• Unraveling the Mystery
• Gregor Mendel discovered the principles of
  heredity while studying the characteristics and
  traits of pea plants.
• A characteristic is a feature that has different
  forms in a population.
• For example, hair color is a characteristic of
  humans.
• The different forms, such as brown or red hair is
  called a trait.

With your elbow partner, name two characteristics
in our class and two different traits of those
characteristics.
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Mendels First Experiments

• One trait was always present in the first
  generation, and the other trait seemed to
  disappear.
• Mendel chose to call the trait that appeared the
  dominant trait.
• Because the other trait seemed to fade into the
  background, Mendel called it the recessive trait.
• The recessive trait for the white flower
  reappeared in the second generation.

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Review Talk with your group

• What is heredity?
• The passing of genetic traits from parent to
  offspring
• Who was Gregor Mendel?
• Discovered the principles, or ideas, of heredity
• Which trait is present in the first generation?
• Dominant trait
• Which trait is present in the second generation?
• Recessive trait

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Challenge Question

• So how is it that both of my parents are short,
  but I am tall?

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The Family Connections

• You and your partner will help each other
  determine the variation of each characteristic
  (trait) that each of you possess. Record your
  traits in the chart labeled My Characteristics
  on the back of the sheet.

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Traits and Inheritance

• Mendel knew from his experiment with pea plants
  that there must be two sets of instructions for
  each characteristic.
• These instructions for an inherited trait are
  called genes.
• Each parent gives one set of genes to the
  offspring.
• The offspring then has two forms of the same gene
  for every characteristic- one from each parent.
• The two forms (often dominant and recessive) of a
  gene are known as alleles.
• Dominant alleles are shown with a capital letter
  (P for dominant purple flowers).
• Recessive alleles are shown with a lowercase
  letter (p for recessive white flowers).

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Just a side note
Take a Look _at_ pgs. 110-111!
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Bell Work 2/12/14

• Review Question
• What is the difference between a gene and an
  allele?
• Challenge Question
• Mendel calculated that ratio of dominant traits
  to recessive traits. He found a ratio of 31.
  What did this tell him about how traits are
  passed from parents to offspring?

THINK. PAIR. SHARE.
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Objectives

• Describe the relationship among genes,
  chromosomes, and inherited traits. (SPI
  0707.4.3)
• Interpret a Punnett square to predict possible
  genetic combinations passed from parents to
  offspring during sexual reproduction.
  (SPI0707.4.4)

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Phenotype Genotype

• Genes affect the traits of an offspring.
• An organisms appearance (the way they look) is
  known as its phenotype.
• In pea plants, possible phenotypes for the
  characteristic of flower color would be purple
  flowers or white flowers.
• The genotype of an organism is the entire genetic
  makeup of an organism the combination of genes
  for a specific trait.
• An organism with two dominant or two recessive
  alleles is homozygous (same size letters- PP or
  pp).
• An organism with one of each (Pp) is heterozygous.

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Inherited Disorders

• Albinism is an inherited disorder that affects a
  persons phenotype in many ways.
• The boy in the picture has inherited a condition
  called albinism.
• Albinism prevents hair, skin, and eyes from
  having normal coloring because that persons gene
  for producing melanin is mutated.

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Punnett Square

• A Punnett square is used to organize all possible
  combinations of offspring from particular
  parents.
• Genotype PP is a purebred.
• What is the genotype for the offspring to the
  right?
• The dominant allele P ensures that the offspring
  will have purple flowers.
• The recessive allele p may get passed to the next
  generation.
• Why?

THINK. PAIR. SHARE.
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Quick Labpg. 107
R round seeds r wrinkled seeds

• Work with your group to complete the Punnett
  square.
• What would be the phenotypes for these offspring?
• RR round seeds
• Rr round seeds
• rr wrinkled seeds

R
r


RR (genotype- two dominant alleles)
Rr (genotype- one dominant allele,one recessive
allele)
R
Rr (genotype- one dominant allele,one recessive
allele)
rr (genotype- two recessive alleles)
r
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Probability

• The mathematical chance that something will
  happen is known as probability.
• Genotype probability
• Pp x Pp cross has a 50 chance of receiving
  either allele from either parent.
• The probability of inheriting two p alleles is
  ½x½, which equals ¼, or 25.

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Monohybrid vs. Dihybrid Punnett Square

• A monohybrid Punnett square is one where only one
  trait is crossed.
• Example A tall pea plant TT is crosses with a
  short pea plant tt.

• A dihybrid Punnett square is one where two traits
  are crossed.
• Example a tall, green flowered plant TtGg is
  crossed with a short, yellow flowered plant ttgg.

T T
t Tt Tt
t Tt Tt
TG Tg tG tg
tg TtGg Ttgg ttGg Ttgg
tg TtGg Ttgg ttGg Ttgg
tg TtGg Ttgg ttGg Ttgg
tg TtGg Ttgg ttGg Ttgg
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Rr x rr
R round seeds r wrinkled seeds
INDIVIDUAL ASSESSMENT



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RrYy x rryy
ELBOW PARTNERS
R round seeds r wrinkled seeds Y yellow
seeds y green seeds





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SpongeBob Genetics

• Scientists at Bikini Bottoms have been
  investigating the genetic makeup of the organisms
  in this community.
• Use the information provided and your knowledge
  of genetics to complete the SpongeBob Genetics
  packet.

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Exit Ticket

• Create your own monohybrid Punnett Square cross.
• Use the examples in your notes for ideas.