nondisjunction

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Word: Nondisjunction

Part of Speech: Noun

Definition: Nondisjunction is a biological term that describes a mistake that happens during cell division (specifically meiosis), where the chromosomes (the structures in our cells that carry genetic information) do not separate properly. This can lead to cells having an unusual number of chromosomes, which can cause genetic disorders.

Usage Instructions:

• When to Use: Use "nondisjunction" when discussing topics related to genetics, biology, or diseases caused by chromosome abnormalities.
• Context: It is often mentioned in discussions about genetic conditions or during explanations of how cells divide.

Example Sentence:

• "Nondisjunction during meiosis can lead to conditions like Down syndrome, where a person has an extra copy of chromosome 21."

Advanced Usage:

In advanced discussions, you might encounter phrases like "meiotic nondisjunction" to specify that the error occurs during the first or second round of meiosis.

Word Variants:

• Nondisjunctional (adjective): Relating to nondisjunction.
  • Example: "Nondisjunctional errors can result in various genetic disorders."

Different Meaning:

While "nondisjunction" primarily refers to the biological process, in a more general sense, it could also mean any failure to separate or distinguish between two things, though this usage is rare.

Synonyms:

• Chromosomal separation failure
• Chromosome segregation error

Related Terms:

• Disjunction: This is the opposite of nondisjunction, meaning that the chromosomes separate correctly during cell division.
• Aneuploidy: A condition that results from nondisjunction, where there is an abnormal number of chromosomes in a cell.

Idioms and Phrasal Verbs:

While there aren’t specific idioms or phrasal verbs directly related to "nondisjunction," you might come across phrases like "to pair up" (as in chromosomes pairing during meiosis), which emphasizes the connection between chromosomes.

Summary:

Nondisjunction is an important term in genetics that describes a failure in chromosome separation during cell division, leading to potential genetic disorders.

Academic

Noun

1. meiosis in which there is a failure of paired homologous chromosomes to separate; results in an abnormal number of chromosomes in the daughter cells