polar body

noun

: a cell that separates from an oocyte during meiosis and that contains a nucleus produced in the first or second meiotic division and very little cytoplasm

Examples of polar body in a Sentence

Recent Examples on the Web
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
In parthenogenesis, a polar body fuses with the unfertilized egg, triggering it to form an embryo. Stephanie Pappas, Scientific American, 18 Feb. 2024 During spontaneous parthenogenesis, eggs fuse with polar bodies to create a new offspring without the genetic contribution of another parent. Evan Bush, NBC News, 29 Feb. 2024 The egg and each polar body each contain half of the complement of genes needed to make a new organism. Stephanie Pappas, Scientific American, 18 Feb. 2024 During facultative parthenogenesis, however, a polar body fuses with the egg to create the necessary number of chromosomes to give birth. Kyle Melnick, Washington Post, 9 June 2023 The female also produces polar bodies, which are small cells that hold chromosomes nearly identical to the egg. Kyle Melnick, Washington Post, 9 June 2023 But studies of other birds have revealed that on occasion, the polar body somehow merges again with the egg, acting like sperm fertilizing it. Sarah Zhang, The Atlantic, 28 Oct. 2021 If an egg with a W chromosome merges with its polar body, the resulting WW embryo will not be viable. Sarah Zhang, The Atlantic, 28 Oct. 2021 In one version of parthenogenesis called automixis, an animal can merge a polar body with an egg to produce offspring. Corryn Wetzel, National Geographic, 25 Aug. 2020

Word History

First Known Use

1882, in the meaning defined above

Time Traveler
The first known use of polar body was in 1882

Dictionary Entries Near polar body

Cite this Entry

“Polar body.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polar%20body. Accessed 18 Nov. 2024.

Kids Definition

polar body

noun
: a cell that separates from the immature ovum during meiosis and that contains a nucleus produced in the first or second division of meiosis but very little cytoplasm

Medical Definition

polar body

noun
: a cell that separates from an oocyte during meiosis:
a
: one containing a nucleus produced in the first meiotic division

called also first polar body

b
: one containing a nucleus produced in the second meiotic division

called also second polar body

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