Nondisjunction

1.  Watch this video

2.  Study this summary

What Is Nondisjunction?

  • Definition: Nondisjunction is the failure of chromosomes to separate properly during meiosis. If you think about the word, understanding the process becomes a lot easier.
    • Junction: A point where things come together.
    • Disjunction: Things coming apart.
    • Nondisjunction: Failure of things to separate.

How Nondisjunction Happens

  1. During Meiosis I:
    • Homologous chromosomes fail to separate.
    • Resulting gametes:
      • 50% are n+1 (haploid number + 1, with an extra chromosome).
      • 50% are n−1 (haploid number – 1, missing a chromosome).
  2. During Meiosis II:
    • Sister chromatids fail to separate.
    • Resulting gametes:
      • 25% are n+1
      • 25% are n−1
      • 50% are normal.

Consequences of Nondisjunction

Note that symptoms of nondisjunction in humans are not essential knowledge for the AP Bio exam, but could appear on your teacher’s test.

  • Abnormal Gametes:
    • Gametes with n+1 or n−1 can lead to zygotes with abnormal chromosome numbers after fertilization.
  1. Trisomy:
    • Definition: Zygote has an extra chromosome (2n+1).
    • Example: Down syndrome, a trisomy of chromosome 21.
      • Down syndrome is characterized by developmental delays, intellectual disability, distinct facial features (such as a flat facial profile and almond-shaped eyes), and potential health issues like heart defects and low muscle tone.
  2. Monosomy:
    • Definition: Zygote is missing a chromosome (2n−1).
    • Survivability: Most monosomies are not survivable, except for some involving sex chromosomes.

Chromosomal Variations from Nondisjunction of Sex Chromosomes

  1. Turner Syndrome:
    • Cause: Monosomy of the sex chromosomes (X0 only in females).
    • Impact: Affects development but is survivable. Women with Turner syndrome typically have a short stature, delayed or incomplete puberty, and possible infertility. Some individuals may also experience heart or kidney abnormalities and learning difficulties, particularly with spatial reasoning.
  2. Other Variations in Sex Chromosomes:
    • Men with XXY (Klinefelter syndrome). XYY males are taller than average height, have reduced testosterone levels, delayed puberty, reduced muscle mass, and potential infertility. Some individuals may also experience mild learning difficulties.
    • Men with XYY.
    • Women with XXX.
    • These variations result in unique developmental and physical traits.

3. Master these flashcards

[qdeck]
[h] Chromosomal Inheritance: Nondisjunction and Chromosomal Variation

[q] What is nondisjunction?
[a] Nondisjunction is the failure of chromosomes to separate properly during meiosis.

[q] What does the term “junction” refer to, and how does it relate to nondisjunction?
[a]

  • Junction: A point where things come together.
  • Disjunction: Things coming apart.
  • Nondisjunction: Failure of chromosomes to separate.

[q] When does nondisjunction occur during meiosis?
[a]

  1. Meiosis I: Homologous chromosomes fail to separate.
  2. Meiosis II: Sister chromatids fail to separate.

[q] What are the results of nondisjunction during meiosis I?
[a]

  • 50% of gametes are n+1 (extra chromosome).
  • 50% of gametes are n−1 (missing a chromosome).

[q] What are the results of nondisjunction during meiosis II?
[a]

  • 25% of gametes are n+1 (extra chromosome).
  • 25% of gametes are n−1(missing a chromosome).
  • 50% of gametes are normal.

[q] What is a trisomy, and what causes it?
[a] A trisomy occurs when a zygote has an extra chromosome (2n+1), caused by n+1 gametes after nondisjunction.

[q] What is the most common example of trisomy?
[a] Down syndrome, a trisomy of chromosome 21, leading to developmental delays and other effects.

[q] What is a monosomy, and what causes it?
[a] A monosomy occurs when a zygote is missing a chromosome (2n−1), caused by n−1 gametes after nondisjunction.

[q] Are monosomies survivable?
[a] Most monosomies are not survivable, except for some involving sex chromosomes.

[q] What is Turner syndrome?
[a] Turner syndrome is a monosomy where females have only one X chromosome (X0). It affects development but is survivable.

[q] What are some examples of other chromosomal variations caused by nondisjunction?
[a]

  • Men with XXY (Klinefelter syndrome).
  • Men with XYY.
  • Women with XXX.

[q] How does nondisjunction lead to chromosomal variations in gametes?
[a] Nondisjunction causes gametes to have an abnormal number of chromosomes (n+1 or n−1), which results in zygotes with chromosomal abnormalities after fertilization.

 

[/qdeck]

4. Tackle these quizzes

4.1. Nondisjunction: Checking Understanding

[qwiz random = “true” ]

[h]Nondisjunction: Checking Understanding

[i]

[q] In the diagram below, which letter shows a cell that is “2n”?

[textentry single_char=”true”]

[c]IG E=[Qq]

[f]IEV4Y2VsbGVudC4gVGhlIGNlbGwgYXQgJiM4MjIwO2EmIzgyMjE7IGlzIGRpcGxvaWQsIG9yICYjODIyMDsybi4mIzgyMjE7[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBGaW5kIGEgY2VsbCB0aGF0IGhhcyB0d28gc2V0cyBvZiBjaHJvbW9zb21lcy4=[Qq]

[q] In the diagram below, which letter shows a gamete that is “n + 1,” and which resulted from nondisjunction during meiosis I”?

[textentry single_char=”true”]

[c]IG U=[Qq]

[f]IEV4Y2VsbGVudC4gVGhlIGNlbGwgYXQgJiM4MjIwO2UmIzgyMjE7IGlzIG4gKyAxLCBhbmQgcmVzdWx0ZWQgZnJvbSBhIG5vbmRpc2p1bmN0aW9uIHRoYXQgb2NjdXJyZWQgZHVyaW5nIE1laW9zaXMgSSAoYmV0d2VlbiBjZWxsICYjODIyMDthJiM4MjIxOyBhbmQgY2VsbCAmIzgyMjA7Yi4mIzgyMjE7KQ==[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBTdGFydCBieSBmaW5kaW5nIGEgZ2FtZXRlIHRoYXQgaGFzIGFuIGV4dHJhIGNocm9tb3NvbWUgKG1ha2luZyBpdCBuICsgMSkuIFRoZW4sIG1ha2Ugc3VyZSB0aGF0IHRoaXMgY2VsbCByZXN1bHRlZCBmcm9tIG5vbmRpc2p1bmN0aW9uIGR1cmluZyBNZWlvc2lzIEkgKHdoaWNoIGlzIHdoZW4gaG9tb2xvZ291cyBwYWlycyBhcmUgc3VwcG9zZWQgdG8gc2VwYXJhdGUpLg==[Qq]

[q] In the diagram below, which letter shows a gamete that is “n – 1,” and which resulted from nondisjunction during Meiosis II”?

[textentry single_char=”true”]

[c]IG s=[Qq]

[f]IEV4Y2VsbGVudC4gVGhlIGdhbWV0ZSBhdCAmIzgyMjA7ayYjODIyMTsgaXMgbiAmIzgyMTE7IDEsIGFuZCByZXN1bHRlZCBmcm9tIGEgbm9uZGlzanVuY3Rpb24gdGhhdCBvY2N1cnJlZCBkdXJpbmcgTWVpb3NpcyBJSSAoYmV0d2VlbiBjZWxsICYjODIyMDtnJiM4MjIxOyBhbmQgY2VsbCAmIzgyMjA7aC4mIzgyMjE7KQ==[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBTdGFydCBieSBmaW5kaW5nIGEgZ2FtZXRlIHRoYXQgaGFzIGEgbWlzc2luZyBjaHJvbW9zb21lIChtYWtpbmcgaXQgbiAmIzgyMTE7IDEpLiBUaGVuLCBtYWtlIHN1cmUgdGhhdCB0aGlzIGNlbGwgcmVzdWx0ZWQgZnJvbSBub25kaXNqdW5jdGlvbiBkdXJpbmcgTWVpb3NpcyBJSSAod2hpY2ggaXMgd2hlbiBzaXN0ZXIgY2hyb21hdGlkcyBhcmUgc3VwcG9zZWQgdG8gc2VwYXJhdGUpLg==[Qq]

[q] In the diagram below, which letter shows gametes that, when fertilized, will produce a zygote with a trisomy? (Choose one of the two possible answers and enter it below)

[textentry single_char=”true”]

[c]IGU7 IGo=[Qq]

[f]IEV4Y2VsbGVudC4gVGhlIGNlbGxzIGF0ICYjODIyMDtlJiM4MjIxOyBhbmQgJiM4MjIwO2omIzgyMjE7IGFyZSBuICsgMS4gV2hlbiBmZXJ0aWxpemVkIGJ5IGFub3RoZXIgZ2FtZXRlIHRoYXQgaGFzIG9uZSBoYXBsb2lkIHNldCBvZiBjaHJvbW9zb21lcyAobiksIHRoZSByZXN1bHRpbmcgZ2FtZXRlcyB3aWxsIGhhdmUgYSB0cmlzb215Lg==[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBTdGFydCBieSBmaW5kaW5nIHRoZSBnYW1ldGVzIHRoYXQgaGF2ZSBhbiBleHRyYSBjaHJvbW9zb21lIChtYWtpbmcgdGhlbSBuICsgMSku[Qq]

[q] In the diagram below, which letter shows cells that, when fertilized, will produce a zygote with monosomy? Choose one of the two possible answers and enter it below)?

[textentry single_char=”true”]

[c]IGY7 IGs=[Qq]

[f]IEV4Y2VsbGVudC4gVGhlIGNlbGxzIGF0ICYjODIyMDtmJiM4MjIxOyBhbmQgJiM4MjIwO2smIzgyMjE7IGFyZSBuICYjODIxMTsgMS4gV2hlbiBmZXJ0aWxpemVkIGJ5IGFub3RoZXIgZ2FtZXRlIHRoYXQgaGFzIG9uZSBoYXBsb2lkIHNldCBvZiBjaHJvbW9zb21lcyAobiksIHRoZSByZXN1bHRpbmcgZ2FtZXRlcyB3aWxsIGhhdmUgYSBtb25vc29teSAodGhleSYjODIxNztsbCBiZSBtaXNzaW5nIGEgY2hyb21vc29tZSku[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBIZXJlJiM4MjE3O3MgYSBoaW50OiB5b3UgbmVlZCB0byBmaW5kIGEgZ2FtZXRlIHRoYXQgaGFzIGEgbWlzc2luZyBjaHJvbW9zb21lIChtYWtpbmcgaXQgbiAmIzgyMTE7IDEpLg==[Qq]

[q] In the diagram below, which number or letter represents Meiosis I?

[textentry single_char=”true”]

[c]ID E=[Qq]

[f]IEV4Y2VsbGVudC4gTnVtYmVyICYjODIyMDsxJiM4MjIxOyByZXByZXNlbnRzIE1laW9zaXMgSSwgd2hpY2ggaXMgd2hlbiBob21vbG9nb3VzIHBhaXJzIHNlcGFyYXRlLg==[Qq]

[c]IEVudGVyIHdvcmQ=[Qq]

[f]IE5vLCB0aGF0JiM4MjE3O3Mgbm90IGNvcnJlY3Qu[Qq]

[c]ICo=[Qq]

[f]IE5vLiBNZWlvc2lzIEkgaGFzIHR3byBrZXkgZmVhdHVyZXM6IGl0IHNlcGFyYXRlcyBob21vbG9nb3VzIHBhaXJzLCBhbmQgdGhlIGNocm9tb3NvbWVzIHRoYXQgYXJlIHNlcGFyYXRlZCBhcmUgY29tcG9zZWQgb2Ygc2lzdGVyIGNocm9tYXRpZHMgKHNvIHRoZXkmIzgyMTc7cmUgZG91YmxlZCku[Qq]

[q] The non-separation of either homologous pairs or of sister chromatids that can happen during meiosis is called [hangman]

[c]IG5vbmRpc2p1bmN0aW9u[Qq]

[f]IEV4Y2VsbGVudCE=[Qq]

[q] During Meiosis II, sister [hangman] are supposed to be separated.

[c]IGNocm9tYXRpZHM=[Qq]

[f]IEdvb2Qh[Qq]

[q]When an organism has a missing chromosome (instead of a homologous pair) it’s called a [hangman].

[c]bW9ub3NvbXk=[Qq]

[f]IEdyZWF0IQ==[Qq]

[q] When an organism has three chromosomes (instead of a homologous pair) it’s called a [hangman].

[c]IHRyaXNvbXk=[Qq]

[f]IEdyZWF0IQ==[Qq]

[/qwiz]

 

4.2.  Sex determination, Nondisjunction, and Chromosomal Variation

[qwiz random = “true”]

[h]Quiz: Nondisjunction and its consequences
[i]

[q] In the diagram below, the name for what’s happening at the blue arrow is

[c]IHN5bmFwc2lz[Qq]
[c]IGNyb3NzaW5nIG92ZXI=[Qq]
[c]IG5vbi1zZXBhcmF0aW9u[Qq]
[c]IG5vbmRpc2 p1bmN0aW9u[Qq]
[f]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[Qq]
[f]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[Qq]
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[f]IFllcy4gV2hhdCB5b3UgY2FuIHNlZSBpcyB0aGF0IHRoZSBzaXN0ZXIgY2hyb21hdGlkcyBmYWlsZWQgdG8gc2VwYXJhdGUsIGFuZCBib3RoIHdlbnQgdG8gb25lIG9mIHRoZSBkYXVnaHRlciBjZWxscyAobGVhdmluZyB0aGUgb3RoZXIgZGF1Z2h0ZXIgY2VsbCB3aXRob3V0IGFueSBjaHJvbW9zb21lcykuIFRoZSBuYW1lIGZvciB0aGlzIGVycm9yIGlzIG5vbi1kaXNqdW5jdGlvbi4=[Qq]

[q] In the diagram below, which of the numbered daughter cells has a trisomy?

[c]IDE=[Qq]
[c]IDI=[Qq]
[c]ID M=[Qq]
[c]IDQ=[Qq]
[f]IE5vLiBBIHRyaXNvbXkgbWVhbnMgMyBjaHJvbW9zb21lcywgaW5zdGVhZCBvZiBhIGhvbW9sb2dvdXMgcGFpci4gVGhpcyBmaXJzdCBjZWxsIGhhcyBhIGhvbW9sb2dvdXMgcGFpciAodHdvIHNpbmdsZSBjaHJvbW9zb21lcykuIE9uZSBtZW1iZXIgb2YgdGhlIHBhaXIgY2FtZSBmcm9tIHRoZSBzcGVybSwgYW5kIG9uZSBmcm9tIHRoZSBlZ2cuIE5leHQgdGltZSwgbG9vayBmb3IgYSBmZXJ0aWxpemVkIGVnZyAodGhlc2UgYXJlIGFsbCBvbiB0aGUgYm90dG9tIHJvdykgdGhhdCBoYXMgdGhyZWUgY2hyb21vc29tZXMsIGluc3RlYWQgb2YgYSBob21vbG9nb3VzIHBhaXIu[Qq]
[f]IE5vLiBBIHRyaXNvbXkgbWVhbnMgMyBjaHJvbW9zb21lcywgaW5zdGVhZCBvZiBhIGhvbW9sb2dvdXMgcGFpci4gVGhpcyBzZWNvbmQgY2VsbCBoYXMgYSBob21vbG9nb3VzIHBhaXIgKHR3byBzaW5nbGUgY2hyb21vc29tZXMpLiBPbmUgbWVtYmVyIG9mIHRoZSBwYWlyIGNhbWUgZnJvbSB0aGUgc3Blcm0sIGFuZCBvbmUgZnJvbSB0aGUgZWdnLiBOZXh0IHRpbWUsIGxvb2sgZm9yIGEgZmVydGlsaXplZCBlZ2cgKHRoZXNlIGFyZSBhbGwgb24gdGhlIGJvdHRvbSByb3cpIHRoYXQgaGFzIHRocmVlIGNocm9tb3NvbWVzLCBpbnN0ZWFkIG9mIGEgaG9tb2xvZ291cyBwYWlyLg==[Qq]
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[q] In the diagram below, which of the numbered daughter cells has a monosomy?

[c]IDE=[Qq]
[c]IDI=[Qq]
[c]IDM=[Qq]
[c]ID Q=[Qq]
[f]IE5vLiBNb25vc29teSBtZWFucyBvbmUgY2hyb21vc29tZSwgaW5zdGVhZCBvZiBhIGhvbW9sb2dvdXMgcGFpci4gVGhpcyBmaXJzdCBjZWxsIGhhcyBhIGhvbW9sb2dvdXMgcGFpciAodHdvIHNpbmdsZSBjaHJvbW9zb21lcykuIE9uZSBtZW1iZXIgb2YgdGhlIHBhaXIgY2FtZSBmcm9tIHRoZSBzcGVybSwgYW5kIG9uZSBmcm9tIHRoZSBlZ2cuIE5leHQgdGltZSwgbG9vayBmb3IgYSBmZXJ0aWxpemVkIGVnZyAodGhlc2UgYXJlIGFsbCBvbiB0aGUgYm90dG9tIHJvdykgdGhhdCBoYXMganVzdCBvbmUgY2hyb21vc29tZSwgaW5zdGVhZCBvZiBhIGhvbW9sb2dvdXMgcGFpci4gWW91IGNhbiBhbHNvIGxvb2ssIGluIHRoZSByb3cgYWJvdmUsIGZvciBhbiB1bmZlcnRpbGl6ZWQgZWdnIHRoYXTigJlzIG1pc3NpbmcgYSBjaHJvbW9zb21lICh3aGljaCBpbiB0aGlzIGNhc2UsIGlzIHNob3duIGJ5IGFuIGVtcHR5IG51Y2xldXMpLg==[Qq]
[f]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[Qq]
[f]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[Qq]
[f]IEV4Y2VsbGVudC4gTW9ub3NvbXkgbWVhbnMgb25lIGNocm9tb3NvbWUsIGluc3RlYWQgb2YgYSBob21vbG9nb3VzIHBhaXIsIHdoaWNoIGlzIGV4YWN0bHkgd2hhdCB5b3Ugc2VlIGluIGNlbGwgbnVtYmVyIGZvdXIu[Qq]

[q] The image below is a karyotype for

[c]IGEgY2hyb21vc29tYWxs eSBub3JtYWwgbWFsZQ==[Qq]
[c]IGEgY2hyb21vc29tYWxseSBub3JtYWwgZmVtYWxl[Qq]
[f]IFllcy4gTG9vayBhdCB0aGUgbGFzdCBwYWlyIG9mIGNocm9tb3NvbWVzLCBhbmQgbm90ZSB0aGF0IG9uZSBpcyBsYXJnZSwgdGhlIG90aGVyIGlzIHNtYWxsLiBUaGVzZSBhcmUgdGhlIHNleCBjaHJvbW9zb21lcyBvZiBhIG1hbGUgKFggYW5kIFkp[Qq]
[f]IE5vLiBBcyB5b3UgY2FuIHNlZSBieSB0aGUgbGFzdCBwYWlyIG9mIGNocm9tb3NvbWVzLCB0aGlzIHBlcnNvbiBoYXMgYW4gWCBhbmQgYSBZIGNocm9tb3NvbWUgKG9uZSBsYXJnZSwgb25lIHNtYWxsKS4gQSBmZW1hbGUgd291bGQgaGF2ZSB0d28gZXF1YWxseSBzaXplZCBjaHJvbW9zb21lcy4=[Qq]

[q] The image below is a karyotype for

[c]IGEgY2hyb21vc29tYWxseSBub3JtYWwgbWFsZQ==[Qq]
[c]IGEgY2hyb21vc29tYWxs eSBub3JtYWwgZmVtYWxl[Qq]
[f]IE5vLiBMb29rIGF0IHRoZSBsYXN0IHBhaXIgb2YgY2hyb21vc29tZXMsIGFuZCBub3RlIHRoYXQgb25lIGlzIGxhcmdlLCB0aGUgb3RoZXIgaXMgc21hbGwuIFRoZXNlIGFyZSB0aGUgc2V4IGNocm9tb3NvbWVzIG9mIGEgbWFsZSAoWCBhbmQgWSk=[Qq]
[f]IFllcy4gQXMgeW91IGNhbiBzZWUgYnkgdGhlIGxhc3QgcGFpciBvZiBjaHJvbW9zb21lcywgdGhpcyBwZXJzb24gaGFzIHR3byDigJhY4oCZIGNocm9tb3NvbWVzLCBtYWtpbmcgaGVyIGZlbWFsZS4=[Qq]

[q] Which of the following statements about sex chromosomes and gametes is true?
[c]IE1hbGVzIHBhc3Mgb24gYSDigJhZ4oCZIGNocm9tb3NvbWUgaW4gdGhlaXIgZ2FtZXRlcy4gRmVtYWxlcyBwYXNzIG9uIGFuIOKAmFjigJkgY2hyb21vc29tZS4=[Qq]
[c]IGJvdGggbWFsZXMgYW5kIGZlbWFsZXMgY2FuIGNyZWF0ZSBnYW1ldGVzIHRoYXQgY2FycnkgYSDigJhZ4oCZIGNocm9tb3NvbWUgb3IgYW4g4oCYWOKAmSBjaHJvbW9zb21lLg==[Qq]
[c]IFdoZW4gYSBtYW4gcHJvZHVjZXMgZ2FtZXRlcywgaGFsZiBvZiBoaXMgc3Blcm0gd2lsbCBjYXJyeSBhbiDigJhY4oCZIGNocm9tb3NvbWUsIGFuZCBoYWxmIG9mIGhpcyBzcG VybSB3aWxsIGNhcnJ5IGEg4oCYWeKAmSBjaHJvbW9zb21lLiBCeSBjb250cmFzdCwgYWxsIG9mIGEgd29tYW7igJlzIGVnZ3Mgd2lsbCBjYXJyeSBhbiBYIGNocm9tb3NvbWUu[Qq]
[f]IE5vLiBBIG1hbuKAmXMgc2V4IGNocm9tb3NvbWVzIGFyZSDigJhYWSzigJkgRHVyaW5nIG1laW9zaXMsIHRoZSBYIGFuZCBZIGNocm9tb3NvbWVzLCB3aGljaCBhcmUgaG9tb2xvZ291cywgd2lsbCBzZXBhcmF0ZS4gVGhlIHJlc3VsdGluZyBnYW1ldGVzIHdpbGwgZWl0aGVyIGhhdmUgYW4gWCBjaHJvbW9zb21lLCBvciBhIFkgY2hyb21vc29tZS4gWW91IGFyZSwgaG93ZXZlciwgcmlnaHQgYWJvdXQgdGhlIGZlbWFsZTogYSBmZW1hbGXigJlzIHNleCBjaHJvbW9zb21lcyBhcmUg4oCYWFgu4oCZIEFzIGEgcmVzdWx0LCBhbGwgb2YgdGhlIGVnZ3MgdGhhdCBzaGUgcHJvZHVjZXMgd2lsbCBoYXZlIGFuIFggY2hyb21vc29tZS4=[Qq]
[f]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[Qq]
[f]IFRoYXTigJlzIHJpZ2h0LiBBIG1hbuKAmXMgc2V4IGNocm9tb3NvbWVzIGFyZSDigJhYWSzigJkgRHVyaW5nIG1laW9zaXMsIHRoZSBYIGFuZCBZIGNocm9tb3NvbWVzLCB3aGljaCBhcmUgaG9tb2xvZ291cywgd2lsbCBzZXBhcmF0ZS4gVGhlIHJlc3VsdGluZyBnYW1ldGVzIHdpbGwgZWl0aGVyIGhhdmUgYW4gWCBjaHJvbW9zb21lLCBvciBhIFkgY2hyb21vc29tZS4gQSBmZW1hbGXigJlzIHNleCBjaHJvbW9zb21lcyBhcmUg4oCYWFgu4oCZIEFzIGEgcmVzdWx0LCBhbGwgb2YgdGhlIGVnZ3MgdGhhdCBzaGUgcHJvZHVjZXMgd2lsbCBoYXZlIGFuIFggY2hyb21vc29tZS4=[Qq]

[q] Which of the following statements about sex determination in humans is true?
[c]IFRoZSBlZ2cgZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIGEgZmVtYWxlLiBUaGUgc3Blcm0gZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIGEgbWFsZS4=[Qq]
[c]IFRoZSBzcGVybSBkZXRlcm1pbmVzIHRo ZSBzZXggb2YgdGhlIG9mZnNwcmluZy4=[Qq]
[c]IFRoZSBlZ2cgZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIHRoZSBvZmZzcHJpbmcu[Qq]
[f]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[Qq]
[f]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[Qq]
[f]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[Qq]

[q] The image below shows the sex chromosomes of male and female fruit flies. Based on the diagram, you can infer that in fruit flies


[c]IFRoZSBlZ2cgZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIGEgZmVtYWxlLiBUaGUgc3Blcm0gZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIGEgbWFsZS4=[Qq]
[c]IFRoZSBzcGVybSBkZXRlcm1pbmVzIHRo ZSBzZXggb2YgdGhlIG9mZnNwcmluZy4=[Qq]
[c]IFRoZSBlZ2cgZGV0ZXJtaW5lcyB0aGUgc2V4IG9mIHRoZSBvZmZzcHJpbmcu[Qq]
[f]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[Qq]
[f]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[Qq]
[f]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[Qq]

[q] What’s the best diagnosis of the karyotype below?

[c]IEEgY2hyb21vc29tYWxseSBub3JtYWwgbWFsZQ==[Qq]
[c]IFR1cm5lciBT eW5kcm9tZQ==[Qq]
[c]IEtsaW5mZWx0ZXIgU3luZHJvbWU=[Qq]
[c]IERvd24gU3luZHJvbWU=[Qq]
[f]IE5vLiBMb29rIGF0IHRoZSBzZXggY2hyb21vc29tZXMuIEEgY2hyb21vc29tYWxseSBub3JtYWwgbWFsZSB3b3VsZCBoYXZlIGFuIFggYW5kIGEgWSBjaHJvbW9zb21lLiBOZXh0IHRpbWUsIGNob29zZSBhIGRpZmZlcmVudCBhbnN3ZXIu[Qq]
[f]IFllcy4gQXMgeW91IGNhbiBzZWUsIHRoaXMgZmVtYWxlIGhhcyBhIHNpbmdsZSBYIGNocm9tb3NvbWUsIHdoaWNoIGlzIHRoZSBjaHJvbW9zb21hbCBjYXVzZSBvZiBUdXJuZXIgc3luZHJvbWUu[Qq]
[f]IE5vLiBMb29rIGF0IHRoZSBzZXggY2hyb21vc29tZXMuIFlvdSBjYW4gc2VlIHRoYXQgdGhlcmXigJlzIGEgc2luZ2xlIFggY2hyb21vc29tZS4gS2xpbmVmZWx0ZXIgaXMgYSBzeW5kcm9tZSB0aGF0IGltcGFjdHMgbWFsZXMsIGFuZCBpdOKAmXMgY2F1c2VkIGJ5IGFuIGV4dHJhIFggY2hyb21vc29tZSAoYXMgb3Bwb3NlZCB0byBhIG1pc3NpbmcgWCBjaHJvbW9zb21lLCB3aGljaCBpcyB3aGF0IHlvdSBzZWUgaGVyZS4=[Qq]
[f]IE5vLiBEb3duIHN5bmRyb21lIGlzIGNhdXNlZCBieSBhbiBleHRyYSAyMXN0IGNocm9tb3NvbWUgKHRyaXNvbXkgMjEpLiBUaGlzIHBlcnNvbiBvbmx5IGhhcyB0d28gMjFzdCBjaHJvbW9zb21lcy4=[Qq]

[q] What’s the best diagnosis of the karyotype below?

[c]IEEgY2hyb21vc29tYWxseSBub3JtYWwgbWFsZQ==[Qq]
[c]IFR1cm5lciBTeW5kcm9tZQ==[Qq]
[c]IEtsaW5mZWx0ZX IgU3luZHJvbWU=[Qq]
[c]IERvd24gU3luZHJvbWUu[Qq]
[f]IE5vLiBMb29rIGF0IHRoZSBzZXggY2hyb21vc29tZXMuIFRoZXJlIGFyZSB0d28gWCBjaHJvbW9zb21lcyBhbmQgYSBZIGNocm9tb3NvbWUuIEEgY2hyb21vc29tYWxseSBub3JtYWwgbWFsZSB3b3VsZCBoYXZlIGp1c3Qgb25lIFggY2hyb21vc29tZSBhbmQgb25lIFkgY2hyb21vc29tZS4gTmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyLg==[Qq]
[f]IE5vLiBMb29rIGF0IHRoZSBzZXggY2hyb21vc29tZXMuIFRoZXJlIGFyZSB0d28gWCBjaHJvbW9zb21lcyBhbmQgYSBZIGNocm9tb3NvbWUuIEEgcGVyc29uIHdpdGggVHVybmVyIHN5bmRyb21lIGhhcyBhIHNpbmdsZSBYIGNocm9tb3NvbWUgKFhPKS4gTmV4dCB0aW1lLCBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyLg==[Qq]
[f]IEV4YWN0bHkuIExvb2sgYXQgdGhlIHNleCBjaHJvbW9zb21lcy4gVGhlcmUgYXJlIHR3byBYIGNocm9tb3NvbWVzIGFuZCBhIFkgY2hyb21vc29tZS4gVGhpcyBpcyB0aGUgY2hyb21vc29tYWwgY2F1c2Ugb2YgS2xpbmVmZWx0ZXIgc3luZHJvbWUgKFhYWSku[Qq]
[f]IE5vLiBEb3duIHN5bmRyb21lIGlzIGNhdXNlZCBieSBhbiBleHRyYSAyMXN0IGNocm9tb3NvbWUgKHRyaXNvbXkgMjEpLiBUaGlzIHBlcnNvbiBvbmx5IGhhcyB0d28gMjFzdCBjaHJvbW9zb21lcy4=[Qq]

[q] What’s the best diagnosis of the karyotype below?

[c]IERvd24gU3 luZHJvbWUu[Qq]
[c]IFR1cm5lciBTeW5kcm9tZQ==[Qq]
[c]IEtsaW5mZWx0ZXIgU3luZHJvbWU=[Qq]
[f]IFllcy4gRG93biBzeW5kcm9tZSBpcyBjYXVzZWQgYnkgYW4gZXh0cmEgMjFzdCBjaHJvbW9zb21lICh0cmlzb215IDIxKS4=[Qq]
[f]IE5vLiBBIHBlcnNvbiB3aXRoIFR1cm5lciBzeW5kcm9tZSBoYXMgYSBzaW5nbGUgWCBjaHJvbW9zb21lIChYTykuIEluIHRlcm1zIG9mIHRoZSBzZXggY2hyb21vc29tZXMsIHRoaXMgcGVyc29uIGlzIGEgbm9ybWFsIG1hbGUsIHdpdGggYW4gWCBhbmQgYSBZIGNocm9tb3NvbWUuIFRoZSB0aGluZyB0byBsb29rIGZvciBoZXJlIGlzIHRoZSAyMXN0IGNocm9tb3NvbWUuIFRha2UgYSBsb29rLCBhbmQgY2hvb3NlIGEgZGlmZmVyZW50IGFuc3dlciBuZXh0IHRpbWUu[Qq]
[f]IE5vLiBBIG1hbiB3aXRoIEtsaW5lZmVsdGVyIHN5bmRyb21lIGhhcyB0d28gWCBjaHJvbW9zb21lcywgYW5kIGEgWSBjaHJvbW9zb21lIChYWFkpLiBJbiB0ZXJtcyBvZiB0aGUgc2V4IGNocm9tb3NvbWVzLCB0aGlzIHBlcnNvbiBpcyBhIG5vcm1hbCBtYWxlLCB3aXRoIGFuIFggYW5kIGEgWSBjaHJvbW9zb21lLiBUaGUgdGhpbmcgdG8gbG9vayBmb3IgaGVyZSBpcyB0aGUgMjFzdCBjaHJvbW9zb21lLiBUYWtlIGEgbG9vaywgYW5kIGNob29zZSBhIGRpZmZlcmVudCBhbnN3ZXIgbmV4dCB0aW1lLg==[Qq]

[q] The chromosomal pattern associated with Turner syndrome is
[c]IFRyaXNvbXkgMjE=[Qq]
[c]IFhYWQ==[Qq]
[c]IF hP[Qq]
[c]IFhZWQ==[Qq]
[f]IE5vLiBUcmlzb215IDIxIGlzIGFzc29jaWF0ZWQgd2l0aCBEb3duIFN5bmRyb21lLiBUdXJuZXIgc3luZHJvbWUgaXMgZm91bmQgb25seSBpbiBmZW1hbGVzIGFuZCBpbnZvbHZlcyBpbmhlcml0aW5nIGEgc2luZ2xlIFggY2hyb21vc29tZS4gVXNlIHRoYXQgaW5mb3JtYXRpb24gdG8gY2hvb3NlIGEgZGlmZmVyZW50IGFuc3dlciBuZXh0IHRpbWUu[Qq]
[f]IE5vLiBYWFkgaXMgYXNzb2NpYXRlZCB3aXRoIEtsaW5lZmVsdGVyIHN5bmRyb21lLiBUdXJuZXIgc3luZHJvbWUgaXMgZm91bmQgb25seSBpbiBmZW1hbGVzIGFuZCBpbnZvbHZlcyBpbmhlcml0aW5nIGEgc2luZ2xlIFggY2hyb21vc29tZS4gVXNlIHRoYXQgaW5mb3JtYXRpb24gdG8gY2hvb3NlIGEgZGlmZmVyZW50IGFuc3dlciBuZXh0IHRpbWUu[Qq]
[f]IFllcy4gVHVybmVyIHN5bmRyb21lIGlzIGNhdXNlZCBieSB0aGUgaW5oZXJpdGFuY2Ugb2YgYSBzaW5nbGUgWCBjaHJvbW9zb21lLCByZXByZXNlbnRlZCBieSB0aGUgbm90YXRpb24gWE8u[Qq]
[f]IE5vLiBYWVkgaXMgY2F1c2VkIGJ5IHRoZSBpbmhlcml0YW5jZSBvZiBhbiBleHRyYSBZIGNocm9tb3NvbWUuIFR1cm5lciBzeW5kcm9tZSBpcyBmb3VuZCBvbmx5IGluIGZlbWFsZXMgYW5kIGludm9sdmVzIGluaGVyaXRpbmcgYSBzaW5nbGUgWCBjaHJvbW9zb21lLiBVc2UgdGhhdCBpbmZvcm1hdGlvbiB0byBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyIG5leHQgdGltZS4=[Qq]

[q] The chromosomal pattern associated with Klinefelter syndrome is
[c]IFRyaXNvbXkgMjE=[Qq]
[c]IFhY WQ==[Qq]
[c]IFhP[Qq]
[c]IFhZWQ==[Qq]
[f]IE5vLiBUcmlzb215IDIxIGlzIGFzc29jaWF0ZWQgd2l0aCBEb3duIFN5bmRyb21lLiBLbGluZWZlbHRlciBzeW5kcm9tZSBvY2N1cnMgaW4gbWFsZXMgd2hvIGluaGVyaXQgYW4gZXh0cmEgWCBjaHJvbW9zb21lLiBVc2UgdGhhdCBpbmZvcm1hdGlvbiB0byBjaG9vc2UgYSBkaWZmZXJlbnQgYW5zd2VyIG5leHQgdGltZS4=[Qq]
[f]IFllcy4gWFhZIGlzIGFzc29jaWF0ZWQgd2l0aCBLbGluZWZlbHRlciBzeW5kcm9tZS4gS2xpbmVmZWx0ZXIgc3luZHJvbWUgb2NjdXJzIGluIG1hbGVzIHdobyBpbmhlcml0IGFuIGV4dHJhIFggY2hyb21vc29tZS4=[Qq]
[f]IE5vLiBUdXJuZXIgc3luZHJvbWUgaXMgY2F1c2VkIGJ5IHRoZSBpbmhlcml0YW5jZSBvZiBhIHNpbmdsZSBYIGNocm9tb3NvbWUsIHJlcHJlc2VudGVkIGJ5IHRoZSBub3RhdGlvbiBYTy4gS2xpbmVmZWx0ZXIgc3luZHJvbWUgb2NjdXJzIGluIG1hbGVzIHdobyBpbmhlcml0IGFuIGV4dHJhIFggY2hyb21vc29tZS4gVXNlIHRoYXQgaW5mb3JtYXRpb24gdG8gY2hvb3NlIGEgZGlmZmVyZW50IGFuc3dlciBuZXh0IHRpbWUu[Qq]
[f]IE5vLiBYWVkgaXMgY2F1c2VkIGJ5IHRoZSBpbmhlcml0YW5jZSBvZiBhbiBleHRyYSBZIGNocm9tb3NvbWUuIEtsaW5lZmVsdGVyIHN5bmRyb21lIG9jY3VycyBpbiBtYWxlcyB3aG8gaW5oZXJpdCBhbiBleHRyYSBYIGNocm9tb3NvbWUuIFVzZSB0aGF0IGluZm9ybWF0aW9uIHRvIGNob29zZSBhIGRpZmZlcmVudCBhbnN3ZXIgbmV4dCB0aW1lLg==[Qq]

[q] The chromosomal pattern associated with Down syndrome is
[c]IFRyaXNv bXkgMjE=[Qq]
[c]IFhYWQ==[Qq]
[c]IFhP[Qq]
[c]IFhZWQ==[Qq]
[f]IFllcy4gVHJpc29teSAyMSBpcyBhc3NvY2lhdGVkIHdpdGggRG93biBTeW5kcm9tZS4gVHJpc29teSAyMSBpcyBhbm90aGVyIHdheSBvZiBzYXlpbmcgdGhhdCB0aGVyZSBhcmUgdGhyZWUgY2hyb21vc29tZXMsIGluc3RlYWQgb2YgdHdvIChhIGhvbW9sb2dvdXMgcGFpciku[Qq]
[f]IE5vLiBYWFkgaXMgYXNzb2NpYXRlZCB3aXRoIEtsaW5lZmVsdGVyIHN5bmRyb21lLiBEb3duIHN5bmRyb21lIGlzIGNhdXNlZCBieSBhbiBleHRyYSBjaHJvbW9zb21lLCBidXQgbm90IGluIHRoZSBzZXggY2hyb21vc29tZXMuIFNlZSBpZiB5b3UgY2FuIGZpbmQgdGhhdCBleHRyYSBjaHJvbW9zb21lIGluIHRoaXMgaW1hZ2Ugd2hlbiB5b3Ugc2VlIHRoaXMgcXVlc3Rpb24gYWdhaW4u[Qq]
[f]IE5vLiBYTyBpcyBhc3NvY2lhdGVkIHdpdGggVHVybmVyIHN5bmRyb21lLCBhbmQgaXQgaW52b2x2ZXMgYSBtaXNzaW5nIFggY2hyb21vc29tZS4gRG93biBzeW5kcm9tZSBpcyBjYXVzZWQgYnkgYW4gZXh0cmEgY2hyb21vc29tZSwgYnV0IG5vdCBpbiB0aGUgc2V4IGNocm9tb3NvbWVzLiBTZWUgaWYgeW91IGNhbiBmaW5kIHRoYXQgZXh0cmEgY2hyb21vc29tZSBpbiB0aGlzIGltYWdlIHdoZW4geW91IHNlZSB0aGlzIHF1ZXN0aW9uIGFnYWluLg==[Qq]
[f]IE5vLiBYWVkgaXMgY2F1c2VkIGJ5IHRoZSBpbmhlcml0YW5jZSBvZiBhbiBleHRyYSBZIGNocm9tb3NvbWUuIERvd24gc3luZHJvbWUgaXMgY2F1c2VkIGJ5IGFuIGV4dHJhIGNocm9tb3NvbWUsIGJ1dCBub3QgaW4gdGhlIHNleCBjaHJvbW9zb21lcy4gU2VlIGlmIHlvdSBjYW4gZmluZCB0aGF0IGV4dHJhIGNocm9tb3NvbWUgaW4gdGhpcyBpbWFnZSB3aGVuIHlvdSBzZWUgdGhpcyBxdWVzdGlvbiBhZ2Fpbi4=[Qq]
[x]
[restart]

[/qwiz]

 

What’s Next?

Proceed to the next tutorial, Mendelian Genetics: Key Concepts