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Which of the following statements is false?

A) A typical XX human female has one Barr body.
B) In a cell with X chromosomes lacking the XIC, there is still X inactivation.
C) An individual with Turner Syndrome has no Barr bodies.
D) An individual with Klinefelter syndrome generally has one Barr body.

1 Answer

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Final answer:

The false statement among the options given is option B, which states that X inactivation can still occur in a cell lacking the X Inactivation Center (XIC). Without the XIC, the X chromosome cannot be inactivated. Option B) In a cell with X chromosomes lacking the XIC, there is still X inactivation is a false statement.

Step-by-step explanation:

The student has asked which statement is false regarding Barr bodies and conditions related to sex chromosomes variations. After reviewing information on X chromosome inactivation and characteristics of various syndromes, we can determine the accuracy of each statement given in the question.

  • A) A typical XX human female has one Barr body. - This is true because females have two X chromosomes, and one of them is inactivated to form a Barr body.
  • B) In a cell with X chromosomes lacking the XIC, there is still X inactivation. - This is false because the X Inactivation Center (XIC) is essential for inactivating the X chromosome. Without it, the X chromosome cannot be inactivated.
  • C) An individual with Turner Syndrome has no Barr bodies. - This is true because individuals with Turner Syndrome have only one X chromosome and therefore, there's nothing to inactivate.
  • D) An individual with Klinefelter syndrome generally has one Barr body. - This is true because in Klinefelter syndrome (XXY), one of the X chromosomes is inactivated to form a Barr body.

Based on this information, the false statement is option B, as the presence of the XIC is necessary for X inactivation to occur.

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