block day- april 18, 2012
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Block Day- April 18, 2012. Homework : None Make an entry : Entry 37: Mitosis vs. Meiosis -4/18/12 Complete the chart. Mitosis vs. Meiosis. Mitosis Meiosis Mitosis Mitosis Meiosis Meiosis. Meiosis Meiosis Mitosis Meiosis Meiosis Mitosis Both. Make an entry. - PowerPoint PPT PresentationTRANSCRIPT
Block Day- April 18, 2012Homework: None
Make an entry: Entry 37: Mitosis vs. Meiosis-4/18/12Complete the chart
Mitosis vs. Meiosis1)Meiosis2) Meiosis3)Mitosis4) Meiosis5)Meiosis6) Mitosis7)Both
8)Mitosis9) Meiosis10)Mitosis11)Mitosis12)Meiosis13)Meiosis
Make an entryEntry 38: Karyotypes-4/18/12
Definition:A karyotype is a
picture of a person’s chromosomes.
Cut out from picture and match each in pairs
In a karyotype, homologous pairs of chromosomes are matched and labeled.
How do we identify homologous chromosome pairs?
1. Size2. Stain with a dye to produce a pattern of
bands (banding pattern)3. Position of the centromere
Centromere
Gender determination• Females have 2 “X” chromosomes.• Males have 1 “X” and 1 “y” chromosome.
X XFemale
X yMale
Why make karyotypes?• Some diseases are caused by problems
with chromosomes– Extra chromosomes– Missing chromosomes– Broken chromosomes
• Making karyotypes allows scientists to identify these diseases.
Example karyotypesUsing karyotypes to predict disease
Chromosomal Abnormalities• Caused by problems in Meiosis
– Errors in Meiosis
• Cannot be detected until the embryo (baby) is already made
Detecting Chromosomal Abnormalities
Amniocentesis
Chromosomal Abnormalities
• Some chromosomal abnormalities are linked to maternal age (Down’s Syndrome)
Amniocentesis
• High-Risk mothers and mothers who have odd test results may get an Amniocentesis– An “amnio” is a sample of the amniotic fluid that surrounds the
baby. This fluid contains the baby’s cells.
Amniocentesis
• From the Amniocentesis, a karyotype can be made.
Disease (extra chromosome)
Normal (complete set of chromosomes)
Karyotype Lab• Get a laptop, write down your number - log in to computer and wait!• Go to the pickup work folder and open the
document “Links for Karyotype Lab”
• Using the links- complete the fill in the blank notes on the chromosomal disorders: Down, Turner, and Kleinfelter syndromes.
When you are finished-
Tape this into the Karyotype entry- Shut down your laptop