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ASSESSMENT REMINDER: If you FAIL (below 70%) an assessment, regardless of the type, you can retest (following reteach) the objective you failed for a maximum.

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Presentation on theme: "ASSESSMENT REMINDER: If you FAIL (below 70%) an assessment, regardless of the type, you can retest (following reteach) the objective you failed for a maximum."— Presentation transcript:

1 ASSESSMENT REMINDER: If you FAIL (below 70%) an assessment, regardless of the type, you can retest (following reteach) the objective you failed for a maximum of a 70%. The retest must be done within 1 week of receiving your test back and must be done during tutorials. If you pass an assessment that is short answer you receive the grade you got (just like last semester) and are not able to correct short answers. If you pass an assessment that has a multiple choice portion you may CORRECT the multiple choice portion you missed for 1 point each. Corrections are made during tutorials and must be done within 1 week of receiving your test back. (Just like last semester….!) You don’t have to schedule to retest or make corrections! Your ticket in to retest/correct is your original assessment! 6e, 6f, assessment reteach, retest, MC corrections will be the Week of February 9-13 th during tutorials!!! 6f will be given back next week and grades will be in the grade book by Monday for 6f

2 Karyotypes

3 You should be able to answer the following questions by next class (based on handouts…) 1.How many chromosomes are present in a normal human karyotype? 2.What is a karyotype? 3.What is non-disjunction? 4.Which pair of chromosomes represent the sex chromosomes? How can you tell X and Y apart? 5.What is an aneuploidy? 1.Provide at least one example of an aneuploidy 6.What does trisomy mean? What is an example of one? How can you pick it out on a karyotype?

4 Karyotypes Definition - A picture of chromosomes cut out and grouped together. Typical human karyotype: –46 total chromosomes –23 total pairs –44 autosomes –2 sex chromosomes (XX or XY) *An embryo without an X chromosome is incapable of survival

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7 Is the following individual male or female?

8 Is this karyotype of a male or female? question here]

9 “Normal” Human Female “Normal” Human Female Why? Because she lacks a “Y” chromosome.

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11 Is the following individual male or female?

12 Is this karyotype of a male or female? question here] A.Male[Option 1] B.Female

13 “Normal” Human Male “Normal” Human Male Why? Because he has a “Y” chromosome.

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15 Non-disjunction Non-disjunction is a failure of chromosomes to properly separate during either Stage 1 or Stage 2 of meiosis Upon fertilization the zygote may have one too many chromosomes ( trisomy) or one too few chromosomes (monosomy)

16 Which chromosome number shows non-disjunction?

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18 Monosomy X, Female Turner Syndrome Pectus excavatum (picture) Short stature Webbed neck Abnormal eye features (drooping eyelids) Absent or retarded development of secondary sexual characteristics that normally appear at puberty Infertility Dry eyes

19 Which chromosome number shows non-disjunction?

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21 Trisomy 21 Down Syndrome, Female 47, XX, +21

22 Down Syndrome Most commonly known trisomy 1:700 births; 1 in 6 die within 1 st year Average age is 16.2 years Common facial feature Short stature Stubby fingers and toes Large tongue – makes speech difficult

23 Which chromosome number shows non-disjunction

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25 Patau Syndrome (Trisomy 13)

26 1:15,000 births as most fetuses die before term –Of those that survive, 5% live to age 3; 45% die within the first month and 90% die within first year Close set eyes, low set ears Small head Extra fingers and toes Serious eye, brain, and circulatory defects

27 Which chromosome number shows non-disjunction?

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29 XXY Klinefelter Syndrome Tall (around six feet) Hypogonadism (small testes) Unable to produce sperm (infertile) Sparse facial and body hair Gynecomastia (male breast disorder)

30 Which chromosome number shows non-disjunction

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32 XYY Jacob’s Syndrome Tend to have a wiry-build Severe acne Minor birth defects Minor outturning of the elbows Fertility is not affected

33 HOMEWORK, Chromosomal analysis handout (lab station 1) It could be useful to use your karyotype flow chart to answer the questions (especially on notation) Due next class by 9:00 (that would be Tuesday)


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