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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
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
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Word History
First Known Use
1882, in the meaning defined above
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 17 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
More from Merriam-Webster on polar body
Britannica.com: Encyclopedia article about polar body
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