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Reading quiz

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Reading quiz WHY sexual reproduction? Mixes 2 organisms traits to increase the likelihood of passing the BEST traits & increasing survival of that species. – PowerPoint PPT presentation

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Title: Reading quiz


1
Reading quiz
  • WHY sexual reproduction?
  • Mixes 2 organisms traits to increase the
    likelihood of passing the BEST traits
    increasing survival of that species.
  • NOT a guarantee that these BEST traits will all
    show up in 1 offspring. Its RANDOM chance.
    HOPE to get the best.
  • DOES NOT CAUSE EVOLUTION
  • Evolution is driven by many things and MUTATIONS
    is one of them.
  • Cloning (mitosis) CAN have mutations too! Sexual
    Repo (Meiosis) speeds up passing mutations around
    which speeds up the slow process of Evolution.

2
  • Tell me when there is 3 minutes left so I can
    pass back the quiz.
  • See me after school for questions (room 602- 300
    to 330)

3
Web quest review!
4
Meiosis!
  • These notes will be done quickly. They are
    review of your reading web quest. Now is the
    time to ask questions. I will post these notes
    on the hw web so pay attention ask questions?

5
More information on your good friends
Chromosomes!
  • I.) In cells, chromosomes exist in pairs. One
    from mother and one from its father.
  • A.) In humans, we have a total of 46 chromosomes.
    23 chromosomes from mom and 23 chromosomes from
    our dad.

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7
  • 1.) Therefore, we have 23 pairs of chromosomes.
  • 2.) These pairs of chromosomes are called
    HOMOLOGOUS pairs.
  • a.) Same in SIZE and FUNCTION.
  • b.) They have genes for the same TRAITS in the
    same order.

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9
  • 3.) Any cell with 2 sets of chromosomes (1
    complete set from mom and 1 from dad) is called a
    DIPLOID cell.
  • a.) ALL the cells in your body are diploid EXCEPT
    the GAMETES (sex cells).
  • b) Gametes only have one set of chromosomes which
    means they only have 23 chromosomes SO we call
    them HAPLOID
  • c. )WHY? If the chromosome wasnt halved then
    each generation the chromosome number would
    double.

10
Meiosis
  • I.) Specialized cells in reproductive organs
    (OVARIES in females and TESTES in males) undergo
    a form of cell division called meiosis to produce
    haploid gametes.

11
Sperm/Egg
  • You pass on half your genes to offspring
  • You must make a gamete (sperm or egg cell) with
    half of your chromosomes
  • Each gamete randomly receives 1 of the 2 versions
    of each chromosome

12
Meiosis
  • Each parent cell produces 4 haploid daughter
    cells
  • Each daughter cell has 1 set of chromosomes
    (instead of the usual 2) OR (half of the parents
    chromosomes)

13
of Possible Gametes
  • There are 223 possible chromosome combinations to
    make a gamete
  • 8,388,608 possibilities
  • So you are 1 out of 8,388,6082 possibilities
  • You are quite literally 1 in a trillion (1 of
    70,368,744,200,000 possible combinations of your
    parents)

14
Which side of the cell the chromosome lines up on
223 crossing over!!!
15
Whats the Point?
  • Meiosis allows us to have offspring that are
    different and have a unique combination of genes
  • This increases diversity in the population
  • Increased diversity means increased ability for
    the species to survive and adapt to new situations

16
  • HW compare Mitosis Meiosis.
  • Use your brain the worksheet to answer as much
    as possible.
  • Consult your notes/Internet if necessary, just
    not other biology students.
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